Manitoba HVDC Research Centre Inc.

244 Cree Crescent
Winnipeg, Manitoba, Canada R3J 3W1 
T 204 989 1240 F 204 989 1277
sales@pscad.com www.hvdc.ca 

Introduction to PSCAD and

Applications

Training Course Presented by the Manitoba

HVDC Research Centre

Course Date:
Location:
Lead Instructor:

1 / 72
 

PSCAD GETTING-STARTED
TUTORIALS

Getting Started and Basic Features

Prepared by: Dharshana Muthumuni

Date: August 2005
Revision: 3
Date: March12, 2007

  2 / 72 
 

Getting Started - Tutorial 1

Objective(s):
  Getting familiar with PSCAD.


  Getting familiar with different sections of the Master Library.



  Different ways to access the master library.



  Creating a simple case.



  Data entry.


  Plotting and control.



  Interactive controls.


T1.1 Create a new case by using either the Menu or Toolbar . A new case should appear
in the Workspace settings entitled noname [psc] . Right-click on this Workspace settings
entry and select Save As… and give the case a name.

 NOTE: Do not use any spaces in the name!  

Create a folder called c:……/PscadTraining/Tutorial_01. Save the case as case01.psc  

T1.2 Open the main page of your new case. Build a case to study the inrush phenomena
when energizing a transformer. The component data is as shown. The transformer is rated
66/12.47 kV.

R
L 

66 kV,60 Hz Source
R Z+ = 3.9Ohms / 75.58 deg
R
L  Z0 = 14.95 Ohms / 80.46 deg

I  
 a
66 kV BUS
E_66
     K
     R Timed
     B Breaker 
BRK Logic
Open@t0

Y-Y Transform er 

7.5 MVA
Z = 6.14 %      1
     #
Full load loss = 0.3%
No load loss = 0.5%      2
No load current 1 %      #

1 
 e
 6 

 
Fig.1 Transformer energizing circuit.

T1.3 Plot the currents (Ia) and voltages (E_66) on the HV side of the transformer. Note: 
Ia and Ea contains the three waveforms of the three phases.

  3 / 72 
 

Fig.2 Basic steps to create a graph with a selected signal.

T1.4  The LV side of the transformer is not connected to a load or any other system
equipment. The breaker is closed at 0.5 s to energize the transformer 66 kV side.

Inrush is related to core saturation. Verify that saturation is included in the model used
for this simulation.

Ask your instructor to explain the large resistance connected to the HV side.

Inrush current magnitude depends on the ‘point on wave’ switching conditions. Use a
manual switch to operate the breaker. Note the point on wave dependency of the inrush
 peak.

Main ...
BRK_Control
C O
BRK

1  
Fig.3 Two state switch attached to a control panel.

  4 / 72 
 

T1.5  Modify the case to include a 12.47 kV/0.5 MVA (Wound rotor type) induction
machine. This case will be used to study the process of starting an Induction motor. The
component data is as shown.

12.47 kV BUS

81m U/G
54m OH Capacitor  Main ...
800 KVars per phas e R_C1
C O

R_C1 42.5 [uH] 40.94 [uF]

R_C1
I   
 b 
Feeder  EN484 1

 S  C
E  O
 C  U
T  P P
I    I   
 O L 
E
N D
Short line of 7.4 km
Z+ = 0.2 E-4 + j0.3 E-3 Ohms/m
Z0 = 0.3 E-3 + j0.1 E-2 Ohms /m
Use default values for the capacitances
B
  _
Etrv
m
 o
 t  
Timed
Breaker 
E
B_mot Logic
Open@t0
m
 o
 t  
   N
0.001
500 kVA Induction machine.
This block models the mechanical Squerriel Cage Type.
   M
characteristics of a typical load.    I 13.8 kV(L-L) 7.697 kV
(Phase)
Mechanical Torque Irated = 0.02804 [kA]
   L
2 *    W    S T Inertia = 0.7267 [s]
W X 0.8 TIN Stator resistance = 0.005 PU
 0 
.
 0 
.
Rotor Resistance = 0.008
 0   0 
TIN
 

You may use the wire mode to connect different components.

T1.6 Enter the component data.

Note: Use ‘typical’ data for the machine. 

T1.7 Plot the currents on either side of the transformer (ia and ib).

T1.8 The input torque to the machine is equal to 80% of the square of the speed. Derive
this signal using control blocks. i.e

  5 / 72 
 

T m   0.8   w2  

Use control blocks to implement the above equation.

Your instructor will explain the calculation program structure of EMTDC and the
definition of ‘electric’ and ‘control’ type models. 

T1.9 The breaker (initially open) should be closed at 0.2s to start the motor.

T1.10 Plot the machine speed, the mechanical torque and the developed electric torque.

Note: Some variables can be measured from within the component. These are normally
listed under the parameter section ‘Internal output variables’  

If time permits… 

T1.11  Add a load of 1 MVA at 0.8-power factor at 12.47 kV. The same transformer
supplies this load. Does the load see an unacceptable voltage sag during motor start?

  6 / 72 
 

Data:
Motor
500 kVA Induction machine.

Wound rotor Type.

13.8 kV(L-L) 7.697 kV (Phase)

Irated = 0.02804 [kA]

Inertia = 0.7267 [s]

Stator resistance = 0.005 PU

Rotor Resistance = 0.008 PU

Short Line
Short line of 7.4 km

Z+ = 0.2 E-4 + j0.3 E-3 Ohms/m

Z0 = 0.3 E-3 + j0.1 E-2 Ohms/m

Use default values for the capacitances

Mechanical Load model

This block models the mechanical
characteristics of a typical loa d.
Mechanical Torque

2 *
W X 0.8 TIN

Capacitor leg
Capacitor 
800 KVars per phas e

R_C1 42.5 [uH] 40.94 [uF]  

  7 / 72 
 

PSCAD ESSENTIAL TRAINING

Tutorials 1 –  6
1.  Initializing a simulation
2.  Switching study
3.  Transformers and inrush
4.  Transmission lines
5.  Power electronic switching
6.  Induction machine dynamics
7.  Synchronous Machines and controls
8.  Wind farms and doubly fed machines

Prepared by: Dharshana Muthumuni

Date: August 2005
Revision: 2
Date: Feb 16, 2007

  8 / 72 
 

Tutorial 1 – Two Area Power System  – Initializing the simulation to a specific load
flow.

T1.1 Create a new case by using either the Menu or Toolbar. A new case should appear
in the Workspace settings entitled noname  [psc] . Right-click on this Workspace settings
entry and select Save As… and give the case a name.

NOTE: Do not use any spaces in the name!  

Create a folder called c:……/PscadTraining/T_01. Save the case as T_01_a.psc  

T1.2 Open the main page of your new case. Build a case representing a simplified two
area power system as shown in the figure below. A 55 km transmission line connects
Station A to a 100 MW wind farm. All other connections to Station A are represented by
an equivalent 230 kV source. The equivalent source impedance is derived from a steady
state fault study at 60 Hz. The line is represented by its series reactance. The
transformer is represented by its impedance, referred to the 230 kV side.

Wind Farm Station A

100 MVA Transforme r  55 km line
33/230 kV, Z = 0.1 pu 230 kV

0.14 0.074

     L      L
     R      R
     R 230 kV Eq. source      R
P1
Z_positive = 10 Ohms at 88
Q1 deg.
     L      L
     R Z_zero = 7 Ohms at 82 deg.      R

P2

Q2 Q2  
Fig1. Two area system

T1.3 The wind farm is also represented by a network equivalence. The positive sequence
impedance of this source at 33 kV is 1 Ohm at 89 deg.
0
NOTE: Referred to the 230 kV side the impedance value Ans:48.577 at 89  

T1.4 The voltage behind the equivalent impedance at the wind farm is 35 kV. The phase
angle is 7 degrees. Determine the power flow across the line.

Note: Converted to the 230 kV side, the equivalent voltage is 243.939 kV at 7 deg

Note: The simplified calculations are outlined in the accompanying MathCAD worksheet.

  9 / 72 
 

T1.5 Plot the power and reactive power flow at both ends of the line. These signals can
be obtained from the voltage source models as internal outputs.

T1.6 Use proper scale factors inside the Output Channels’ to convert PU values to MW
and MVar. Verify the results.

T1.7 How do you change the time step, the simulation time and the plot time? How do
you determine the simulation time step?

T1.8 Can you save results to external output files for post processing?

T1.9 If you specified to write data to output files, where are they located?

Save the case!

The case should be saved as T_01_b.psc  before proceeding.

Different parts of the simulation model can be arranged inside page modules. PSCAD
allows ‘nested’ page modules. If you make a change to your existing case, PSCAD will
identify the page modules where changes took place. Only these modules will be re-
compiled. (Time savings in large cases)  

T1.10 Create a page module and include the equivalent source for the wind farm inside
this module as shown in the figures 2 and 3. What is the use of the ‘ XNODE’ 
component?

Note:  Your instructor will briefly discuss the use of ‘signal transmitters’   which can also
be used to transmit (control) signals from a page to another.

Wind
a
Farm
0.14 0.074

     L
     R
     R

     L
     R

P2

Q2 Q2  
Fig.2 Main page

  10 / 72 
 

     L
     R a
     R

     L
     R

P1

Q1  
Fig.3. Subpage

Save the case!

The case should be saved as T_01_c.psc  before proceeding.

T1.11 Modify the source at Station A to control its parameters externally. Add a control
panel to specify these values. Can the values be changed during a simulation?

Note:  Make sure that the angle is specified in degrees (parameter setting inside the
source model)

Note: Observe the effect of varying the voltage angle/magnitude on P and Q flow

P 
h  Main : Controls
R
R V230
L  F 
250 90 10
9
60.0 8
7
V  6
5
4
3
R 2
1
L  220 -90
230 0 1

 
Fig.4. External control of the source parameters.

T1.12  Modify the circuit to include breakers, breaker controls, meters and the PSCAD
‘fault component’. The case should look like as shown in figure 5. Plot, E1, I1 and the
rms value of E1.

  11 / 72 
 

Wind BRK2 BRK3

a BRK1 I1
Farm  A
0.14 [H] 0.074 [H] E1 V P 
h 
R
R
L  F 
Timed 60.0
Breaker 
Logic V 
P2 BRK1
Closed@t0 Timed
Breaker  R
L 
Q2 BRK3 Logic
Q2 Timed Closed@t0
Breaker  Timed
Logic Fault
I1 BRK2 Logic
Closed@t0

E1 E1  Fault inception - 0.4 s and at 0.404 s

0 = No Fault
1 = Phase A to Ground
2 = Phase B to Ground
3 = Phase C to Ground
Main : Controls
4 = Phase AB to Ground
5 = Phase AC to Ground V230 Ph230 FTYPE
250 90 10
6 = Phase BC to Ground 9
8
7 = Phase ABC to 7
6
Ground 5
4
8 = Phase AB 3
2
220 -90 1
9 = Phase AC
230 0 1
10 = Phase BC
11 = Phase ABC  
Fig.5. Meters, breakers and faults.

T1.13 Simulate an A-G fault. The fault inception time is 0.4s. The fault duration is 0.5 s.
Note the dc offset of I1.

(The dc offset can cause mal-operation of protection due to CT saturation. We will study
this in later on as a separate example.)

T1.14 What factors influence the initial dc offset and its rate of decay? Change the fault
inception time to 0.404 s and observe the results.

T1.15  Breaker 3 is initially closed. Open and close this breaker at 0.5 s and 0.65 s
respectively.

Save the case!

The case should be saved as T_01_d.psc  before proceeding.

T1.16 Include a FFT block in your simulation cases shown in figure 6. Convert I1 to its
sequence components. Verify the results of the FFT for different fault types. Add a
‘poly -meter’  to observe the frequency spectrum.

Note: The instructor will demonstrate the use of the ‘phasor meter’. 

  12 / 72 
 

1 1 1
2

I1 Mag+ Mag- Mag0

(31) (31) (31)
1 XA Ph+
I1 (31)
F FT
2 XB Ph-
I1 (31)
3 XC Ph0
F = 60.0 [Hz]
(31)
d cA d cB dcC
 
Fig.6. FFT Block.

T1.17 Load the case T_01_e.psc from the example cases given to you as course material.
Study the ‘sequencer units’ available to define a series of timed events.

Save the case!

  13 / 72 
 

Tutorial 2 – Capacitor Switching Study:

T2.1  Create a folder called c:……/PscadTraining/T_02. Save the case T_01_e.psc   as
T_02_a.psc .

The utility plans to add 300 MVars of capacitive reactive power at station A to support
the 230 kV bus voltage. A transient study is required to design equipment of this
installation.

Calculations and simulations are required to determine the values/ratings of the

associated limiting reactors (inrush and outrush)

Modify the simulation case to include a sub-page as shown in fig. 1. 

230 kV
GT230
Voltage s upport
Cap. Bank

P 
h 
R
R
L  F 

60.0
V 

R
L 

Fig.1 Capacitor banks at Station A.

The circuit inside the sub page represents a 230 kV capacitor bank with 4 steps per
phase (see attached diagrams). Each step is rated at 25 Mvar/phase. The capacitor
banks are solidly grounded. The inrush and the outrush reactors sizes are to be
determined so that the switching transients do not exceed the breaker capabilities and
are within the IEEE standards.

The values of the outrush/inrush reactors have been determined using IEEE
C37.06.2000. 

T2.2 Use manual breaker controls to switch the breakers R1, R2 and R4. Also measure
the currents in the breakers.

T2.3 Add a timed breaker component to control breaker R3, measure the currents in R3.

Note: Discuss with your instructor the purpose of making R3 operation controllable.

  14 / 72 
 

T2.4  Add meters to measure the currents and voltages on the system side of the
outrush reactor.

T2.5 Run the case with R1 closed, R2 and R4 open, and R3 set to close at 0.2 s.

T2.6 Observe the peak value and frequency of oscillation of the current in R3.

T2.7 Observe the peak value and frequency of oscillation of the current at the outrush
reactor.

T2.8 Note the differences between (7) and (8). Discuss the results.

Important:   Ensure that you are using the proper time step and for visualization
 purposes, the proper plot step! 

T2.9  A Peak inrush current depends on POW switching. This should be studied to
ensure that the breaker meets the TRV and di/dt capabilities.

T2.10 Use the Multiple Run component to control the R3 closing time. Also record the
currents in Breaker R3 and main feeder current.

Set the multiple run to switch for 5 sequential points on the wave.

Can we do random switching over a cycle?

Can we optimize the run length using a snapshot?

Take a snapshot at 0.199sec and the run multiple run for 20 sequential points on the
wave.

Compare your results with IEEE standard results. Can the simulation time step be
changed when the case is run from a snapshot file?

T2.11 What are some considerations for the selection of time-step for this type of
simulation?

T2.12 EXTRA: Check the impedance spectrum using the ‘Harmonic Impedance’
component. This is an important step in the design of capacitor banks. The addition of
the capacitors can give rise to system resonances that are not acceptable.

Is this circuit appropriate to check for system resonances? Why? (not enough details of
the system around the Station A bus is included to capture the frequency effects)

  15 / 72 
 

1.00E-06
1.00E-06
1.00E-06
1.00E-06
1.00E-06
Series1
1.00E-06
1.00E-06
1.00E-06
1.00E-06
1 3 5 7 9 11 13 15 17 19
 

Save the case!

The case should be saved as T_02_b.psc  before proceeding.

T2.13 Modify the circuit as shown in figure 2 to include surge arrestors.

The surge arrestors should protect the capacitors from switching over voltages. Re-
strike of capacitors breaker can cause large over-voltage transients and is usually the
criteria for the selection of MOVs. Discuss the data entry for the MOV model.

  16 / 72 
 

 0 
.
 0 
 0  Outrush
 3 
1  kJoules
7  Reactors
MOV
I  
m
 o
Closed@t0 v 
Logic
Breaker  MOV
Timed

-
 3  -
 3 
-7  0  .
 9  .
 9 
.  8  0 
.
-7  0 
.  8  0 
.
 9  0   8  0   9  0   8  0 
.  8 
 8   e  5  .7  9   e  5 
R  0 
2  1  R -  6 
 0  3  R 2  -  6 
 0  3 
1   [  
M 3 
2   0  5   3  M 0 
 [  
2   0  5 
 5  V  [    5 
V  [  
M  [   A  M  [  
A  W MM
 [   MM
 [  
R V  W RW V  W
 ]   ]   A  ]    ]   ]   A  ]  
R R
 ]    ]  

Closed@t0
Logic
R1 R2 Breaker  R3 R4
Timed
R2 R4  

Fig.2. Surge arresters.

T2.13 Breaker R3 is initially closed. It is opened at 0.204 s but re-strikes at 0.2124 s.

Observe the energy accumulation in the MOV of phase A. can the MOV handle this
energy? Is a statistical study required to design the MOV ratings?

Save the case!

The case should be saved as T_03_a.psc  before proceeding.

  17 / 72 
 

Tutorial 3 – Inrush current and line energizing.

T3.1  Create a folder called c:……/PscadTraining/T_03. Save the case T_02_b.psc   as
T_03_a.psc .

Open the capacitor main breaker R3. Keep all other breakers closed. Make the ‘fault’
component inactive.

Most transient studies require the accurate modeling of transformers and transmission
lines. Transformer inrush requires the accurate modeling of the non-linear iron core.
Switching transient studies require the modeling of transmission lines to include the
effects frequency dependent line parameters and traveling wave phenomena.

T3.2  Use detailed models to represent the 33/230 kV transformer and the 55 km
transmission line. The transformer has a Y-Y configuration and consists of three single
phase units. The no load current is 1 %. The no load and copper losses are 0.003 pu and
0.002 pu respectively.

The conductor arrangement of the line is as shown below. Use the frequency
dependent phase model to represent the line.

G1 G2
10 [m] C2
10 [m]

C1 5 [m] C3

10 [m]

Tower: 3H5
30 [m]
Conductors: chukar 
Ground_Wires: 1/2"HighStrengthSteel

0 [m]
 
Fig.1. 230 kV Transmission tower.

  18 / 72 
 

Timed Three Phase

Breaker  RMS Voltage Meter 
Logic BRK1B
Open@t0
3 Phase
RMS
Timed
Breaker 
Logic 230 kV
BRK1C GT230
Open@t0
Voltage support
Cap. Bank
BRK2 Line_01 BRK3
Wind
a I2 BRK1A I1
Farm #1 #2
E2 E1 P 
Line_01 Line_01 h 
R
R
L  F 
Timed 60.0
Breaker 
Logic V 
P2 BRK3
Open@t0
R
L 
Q2 Q2
Timed
Timed Fault
I1 Breaker  Logic
Logic BRK2
Open@t0
E1 E1  Fault inception - 0.4 s an d at 0.404 s  
Fig.2. Two-area system model for a transient study.

Inrush Study:

T3.3 Open the breakers #2 and #3. The transformer is energized on no load by closing
the breaker #1. Close breaker 1 at 0.15s and observe the inrush currents.

T3.4  Add a 1 Ohm resister in series with the 33 kV winding and observe the results.
What effect does the resistance have on the decay of the inrush current?

T3.5  Does the breaker closing instant influence the magnitude of inrush? Close the
breaker at 0.1535 s and observe the current on phase A.

T3.6  Enable the ‘single pole operation’ mode of the breaker. Close the poles at instants
when the voltage of the respective phase is at a maximum. Observe results.

T3.7 What situation would cause the transformer to saturate on both halves of a voltage
cycle?

Save the case!

The case should be saved as T_03_b.psc  before proceeding.

  19 / 72 
 

Line Energizing Study: 

T3.8  Close breaker # 1 and open breaker # 3. Include the multiple run component to
control the operation of breaker #2 which is initially open. The closing instant B1 derived
from the multiple run.

Fig.3. Multiple run component for breaker control.

T3.9  The breaker closing instant (B1) should be changed for each run. The breaker is
opened 0.15 s after its closing operation. Set the multiple run to switch for 10 sequential
points on a 60 Hz waveform. Record the peak voltage E1 at the receiving end.

Save the case!

The case should be saved as T_03_c.psc  before proceeding.

Lines on the same right of way:

A 130 km transmission line connects the Generating Station C and Station A. This line
runs parallel to the 55 km line between Station A and the Wind Farm for 20 km from
Station A. The generating voltage is stepped up to the transmission level through an
11/230 kV, Y-Y bank.

T3.10 Extend the model to include the 130 km line and the generator as shown in figure
4. The transmission lines are arranged in a sub page as shown in figure 5.

Save the case!

  20 / 72 
 

Station C
11/230 kV, 500MVA
Z=0.08 PU Three Phase
RMS Voltage Meter 

RL   RRL #1 #2
3 Phase
Zpos = 0.01 Ohms at 89 deg. Line_03 RMS
Zzero = 0.011Ohms an d 80 deg.

Timed
Breaker 
BRK3 Logic
Closed@t0
T lines
230 kV
GT230
Timed Line_01 Voltage support
Breaker  Line_02
Logic BRK2 Cap. Bank
Closed@t0 Line_03 BRK3
I1

BRK2   E1 P 
h 

E2 BRK4
Line_01 Line_02
F 
I4
60.0
E4 V 

Timed
Fault
Logic
 
Fig.4. Three area system

Line_01 Line_02

Line_01
Line_02

Line_03

Line_03  
Fig.5. Line arrangement inside the sub-page.

T3.11  The voltage behind the equivalent source impedance of the voltage source
representing the 4 generators at Station C is 12 kV at 21 degrees.

T3.12 Use the Mathcad worksheet to verify results.

T3.13 Change the configuration of the 11/230 kV transformer to represent a D-Y unit.

Adjust the 11 kV source angle to reflect this change.

  21 / 72 
 

Tutorial 4  – Wind Generator model and a Soft Start mechanism

for the Generator. 
T4.1  Create a folder called c:……/PscadTraining/T_04. Save the case T_03_c.psc   as
T_04_a.psc .

The wind turbines in the wind farm are driving induction generators operating at 33 kV.
The total MVA of the station is 100 MVA. Replace the equivalent source with a detailed
model of an induction generator. Assume all generators at the wind farm are operating
under identical conditions. The induction generator connection is shown in figure 1.
External ro tor
resistance

R R R
r 
 o r 
 o r 
 o
Wind...  t    t    t  
TIME  o  o
+   o
+  + 
DIST Rrotor  r  r  r 
10
Q1 P1
 o    
h      Rrotor   Q P 
m     P 
 o
w
StoT B   e
r  A 
0
0 WIN W
1.0
IM
S Iabc
StoT
a
TL
TIN
 A
-0.8 Ctrl = 1

B
-0.5
Ctrl

 3 
4 
 0 
 [  
 u
DIST F 
 ]  

 
Fig.1. Induction generator.

T4.2 Close breaker #1 at 2 s. Keep all other breakers closed. Assume the machine speed
is at 1 pu before closing breaker A. Has the power flow changed?

T4.3  Calculate the value of the shunt capacitance required to maintain the original
power flow. See Mathcad calculations. Lower the time step to 25 us.

T4.4  Will the system be stable if a sudden wind gust causes the input torque to the
machine to increase by 60% (or 80 %)?

Save the case!

The case should be saved as T_03_b.psc  before proceeding.

  22 / 72 
 

T4.5 Discuss how a small wind generator maybe connected to the system.

Using BRKA appropriately, connect the wind generator to the system at 1 s.

T4.6 Note the line currents on the system side when the wind farm is connected to the
system. Change the initial speed of the machine to 0.6 pu and re run the simulation.
Note the current transients.

A Soft Starter shown in figure 2 is used to limit the starting currents when connecting
the induction generators to the system. The back to back thyristors are used to control
the voltage applied to the machine while its speed builds up. The firing angle
characteristics are given in the table in the file ‘softstart.txt’. Model the circuit shown in
figure 2. The firing controls for the thyristors are shown in figure 3.
FP1

     1

     2

     T [Windfarm] ANG

 ANG

T  BRK_SW

2 
FP3
     2
FP2
TIME 1
BRK_SW
     T

T  BRK_SW

2   A
Ctrl = 1
FP5  ANG

     2
FP4
B
180.0
 ANG1
     T Ctrl

BRKA
T  BRK_SW

2 

FP6

Ea
BRKA

NA Eb NB
Timed
Breaker  Ec
Logic BRKA
Open@t0  
Fig.2. Soft Starter.

  23 / 72 
 

THYRISTOR FIRING PULSE

CONTROL CIRCUIT

 ANG_2  ANG_3
H H
 ANG_1
H
L L
L
2 2
2 FP3 FP5
FP1  ANG1 ANG1
 ANG1  ANG_2  ANG_3
H H
 ANG_1
H
+ L + L
D + D +
+ L
D + 2 2
F F
2 FP4 FP6
F
FP2      0
 .      0
 .
     0      0
     0
 .      8      8
     0      1      1
     8
     1

Va Va Va
Ea Eb Ec
PLL  ANG_1 PLL  ANG_2 PLL ANG_3
Vb theta Vb theta Vb theta
Eb Ec Ea
Vc Vc Vc
Ec Ea Eb  
Fig.3. Firing controls.

T4.7 Observe the starting currents with and without soft start.

  24 / 72 
 

Tutorial 5 – Including a machine model in a simulation.

T5.1  Create a folder called c:……/PscadTraining/T_05. Save the case T_04_c.psc   as
T_05_a.psc .

T5.2  Use the methods discussed in the supplementary exercises to replace the 11 kV
source model with a detailed hydro generator model.

T5.3  Enter the ratings of the machine to reflect the 500 MVA, 11 kV unit. (This may
represent a number of identical units operating in parallel).

T5.4 Include the generator controls in the simulation.

T5.5  The voltage magnitude and the phase angle of the 11 kV source are used to
initialize the machine. Observe the power flow and explain the reasons for minor
differences.

T5.6 Try using suitable control methods to adjust the machine power flow to the original
values.

T5.7 How do we model a thermal generator?

  25 / 72 
 

Tutorial 6 – Doubly fed induction machine model.

T6.1  Create a folder called c:……/PscadTraining/T_06. Load the library file
dqo_new_lib.psl. Load the cases T _06_a and T_06_b.psc   given to you with the course
material. Save this file in your T_06 folder. 

T6.2 Understand the basic concept of the double fed connection.

T6.3 Identify the role of different control blocks in the model.

T6.4  Are all models in the control system found in the master library? Can the user
define custom components and use then along with standard models from the master
library?

T6.5 Verify the operation of the two cases.

D
+
Va -
C
* 1 phisx
 A
Isa 0.037 sT sT X ma g
alfa G r to p
D Valfa 1 + sT Vsmag phsmag
+ B 3 to 2
Vb - Y phi
Transform sT Y X
C G
* beta Vbeta 1 1 + sT phis
C
Isb 0.037 D sT phisy
+
Vc -
C
*
Isc 0.037
 
Stator flux vector

slpang

 A Ira_ref  Iraa
D alfa alfa
Rotor 
2 to 3 B
to Stator  Irb_ref  Irbb
Transform
Q beta beta
C Irc_ref  Ircc
 
Rotor reference currents

  26 / 72 
 

Transient Recovery Voltage Across

Breaker Poles
(TRV)

Prepared by: Dharshana Muthumuni

Date: August 2005
Revision: 2
Date: Feb 16, 2007

  27 / 72 
 

Breaker TRV Studies - Tutorial 1

Objective :
Fundamental aspects of Breaker TRV
Selection of time step
Influence of stray capacitance
Influence of loads and losses (resistance)
IEEE defined breaker capability curves
TRV under fault and normal switching conditions and use of multiple run

T1.1  Open the case T_03_a.psc that was completed in Tutorial 3. Rename this as
T_03_a_trv.psc. Keep breakers #1, #2 and #3 closed and the capacitor banks open. Run
the case and make sure the power flow is as expected.

T1.2 Apply a three phase fault to ground at 0.4s. The duration is 1s.

T1.3 Open breaker #3 at 0.44 s. Observe the voltage across the breaker poles.

T1.4  Discuss the reason for TRV. Now lower the time step to 2 us and observe the
results. This will make clear that for TRV studies, a small time step is necessary.

TRV_ENV(+) TRV_ENV (-) Ea

20

10

-10

-20

-30

0.0200 0.0220 0.0240 0.0260

Fig.1.
0.0280
Breaker
0.0300 0.0320
TRV and the IEEE TRV limits
0.0340

T1.5  In TRV studies, the stray capacitances near the breaker must be modeled
adequately. How do we determine these values?

T1.6  IEEE standards (IEEE C37.011) define the TRV capability curves for different
 breakers. These limits depend on a number of factors.

   Breaker voltage rating

   Fault current rating

   Actual fault level

  28 / 72 
 

Open the two PSCAD included with the course material. The two cases are
TRV_Case_01.psc and TRV_Case_02.psc. TRV_Case_02.psc is from a low voltage
distribution system of a utility in Florida. It was used to identify TRV issues and to
identify corrective measures.

T1.7 Observe how the IEEE TRV limits are simulated.

T1.8 What are the measures available to reduce TRV levels?

  29 / 72 
 

Large Industrial Loads –  Induction

Motor Transients

Objectives:

Induction motor starting

Motor data
Voltage dips and fluctuations - Flicker
Motor starting methods
Motor load types
Soft starting
Reading data from external files
Control blocks
Power electronic switches

Prepared by: Dharshana Muthumuni

Date: August 2005
Revision: 2
Date: Feb 16, 2007

  30 / 72 
 

Induction Machine Dynamics/Transients - Tutorial 1

T1.1 Connect a 13.8 kV, 15 kA induction motor to an infinite bus through a transformer

and a breaker. The infinite bus voltage is 66 kV.

Pm ot Qm ot

     P     r Q
    e
    w
    o
     A      P B
W
0.0
IM
S Is
0.0 #1 #2
BRK 0.001
TL
TIN
13.8 kV,2.2 kA motor 
50.19 MVA, Inertia(J)= 2.2 p u BRK

*
W TIN

W  

T1.2 The load torque applied to the motor is related to the motor speed. Derive a control
 block that will generate a torque signal that is proportional to the speed. (TIN = k*w)

T1.3  The motor is to be switched on to the supply using a breaker. Use a ‘two state’
switch to send a signal to the breaker.

T1.4  Observe the starting characteristics. Plot the line current, speed, Electric and
mechanical torque and the terminal voltage at the machine.

T1.5 What could cause the motor be driven into a generating mode.

T1.6 Load the case ind_motor_starting_01.psc.

This case models the loads of an industrial plant. Identify different components in the
model.

T1.7 Note the voltage dip during motor starting. Is this a power quality concern?

T1.8 What methods can be employed to limit starting transients?

T1.9 What could cause the motor be driven into a generating mode.

  31 / 72 
 

T1.10 Induction motor transients can lead to serious power quality issues. The simulation
example in case ind_motor_starting_01.psc  illustrates the voltage dips seen by the other
loads connected to the transformer. Load and run this case.
a)  Does additional rotor resistance affect the starting transients?
 b)  See the effect of rotating inertia and mechanical damping on the transients.
c)  What are the typical loads types (characteristics) that are encountered in
industry applications?

T1.11 Load the case ind_motor_starting_02.psc.  Note the load torque profile. Observe
the voltage variation at the load terminal.

FP1

   1

   2

   T

T  BRK_SW

2 
FP3
   2
FP2

   T

T  BRK_SW

2 
FP5
   2
FP4

   T

T  BRK_SW

2 

FP6
BRK

a1  A Ea a2

b1 B Eb b2

c1 C Ec c2
 

Fig.2. Soft starter

T1.12  Soft starting methods such as that shown in Fig 2 are used to limit the starting
current of large induction machines. Discuss the current limiting mechanism of this
scheme. Load the case ind_motor_starting_03.psc.
a)  What is the role of the PLL?
 b)  How are signals transmitted from the main page to the sub page?
c)  Can PSCAD read data from external files? List a few applications where this
can be useful?
Verify the operation of the soft switch.

  32 / 72 
 

Fast Front Studies

Lightening Strike

Objectives:

Representing stray capacitances

Representing arresters
Representing Bus-bars
Representing long lines
Positioning of Arresters

Prepared by: Dharshana Muthumuni

Date: August 2005
Revision: 2
Date: Feb 16, 2007

  33 / 72 
 

Fast front studies - Tutorial 1

T1.1  The circuit shown below represents the arrangement of a transformer sub-station.
This model is used to study the over voltages at a transformers terminal during a
lightning strike on a station bus bar.

Stray capacitance
Stray capacitance of equipment
of equipment

     6      6      6      3      3      3

     0      0      0      0      0      0
     0      0      0      0      0      0
1 km Transmission Line      0
 .      0
 .      0
 .      0
 .      0
 .      0
 .
     0      0      0      0      0      0
90 m Station Bus 10 m Station Bus
1 1 1 1 1 1

TA1 TA1 bYC1 bYC1 bYC2 bYC2

Va Vtf  
TA1 bYC1 bYC2
     0      0      0      7      7      7
 .  .  .      2      2      2
     0      0      0      0      0      0
     5      5      5      0
 .      0
 .      0
 .
     3      3      3      0      0      0

P
 Approximate surge
impedance Steep Front
line termination Surge
 Arrester  Winding Capacitance for 
 ABB EXLIM Surge 220 kV Autotransformer 
N  Arrester 192 kV (approximate)

Bx
e B  0 
.
 5 
- * To account for the fundamental
TIME * frequency voltage component,
+ 1.02 Lightning Current
the dc source is set to peak
Bx F ac volts.
e

Simple Lightning Surge 1.2*50 Usec:

  I = 1.02*I1 * [ EXP(-13000 * t) - EXP(-4.4E6 * t) ]

Fig.1. Circuit for lightening study

T1.2 Identify different components of the model

T1.3 How do you represent the transformer? Where do you obtain the data?

T1.4  How are transmission lines and cables represented for the purpose of this study?
Can we justify this representation?

T1.5  Does the position of the arrester have an impact on the over-voltage at the
transformer? Place the arrester at the transformer terminal and observe the over-voltage.

T1.6 What does the dc source represent?

T1.7  How do we model the lightening surge? How do we define parameters for the
surge?

  34 / 72 
 

Ferro-Resonance Investigation

Objectives:

Transformer parameters
Saturation
Selection of the simulation time step

Prepared by: Dharshana Muthumuni

Date: August 2005
Revision: 2
Date: Feb 16, 2007

  35 / 72 
 

Ferro-resonance - Tutorial 1

T1.1  Open the case ferroresonance.psc. This case is used to study a ferro resonance
event during a breaker malfunction.

30MVADistribution Transformer
System Equivalent 230kV/13.2kV,Del ta/Wye-Gnd
Source Representation Ztx=7.65%

VbusA VPriA VSecA

3 Phase  A  A COUPLED  A  A  A
Eq. Source 30 [MVA]
LINEA PI
with VbusB SECTION VPriB VSecB
z1 and z0 B B B B B
#1 #2
LINEB
VbusC VPriC VSecC
C C C C 230.0 13.2 C
LINEC

230 kV, 20 mile Transmission Line

Timed
B  B  B  Breaker  Disable saturation
R R R
K  K  K  LINEA Logic and re run
 0   C 
 0  B  0  A  Closed@t0
.
 0  .
 0  .
 0 
50 MVAr @ 230kV  0   0   0  Timing for Line Breaker 
1  1  1 
 5   5   5 
1.5mH Outrush Reactor  Timed Phase A: Closed (stuck)
Breaker  Secondary Load
Logic Phase B: Opens at 100mSec
LINEB
Closed@t0 Phase C: Closed (stuck)
Output Voltages
2  2  2  0.350 [MW]
.
 5  .
 5  .
 5 
1  1  1  Timed
Breaker 
Logic
LINEC
Closed@t0  

Fig.1. Circuit for Ferro resonance Case Study

T1.2 Check the data entry for transformer saturation. What do different entries represent?

T1.3 Include transformer losses. Do you see a change in results?

T1.4 Open the capacitor banks. Are the results different?

T1.5 Change the line length and observe the results?

T1.6 What effect does the load have on the over voltage transients?

T1.7 Are the transients sensitive to the transformer core characteristics?

  36 / 72 
 

Faults and Current Transformers and

Relays

Prepared by: Dharshana Muthumuni

Date: August 2005
Revision: 2
Date: Feb 16, 2007

  37 / 72 
 

Faults and Current Transformers and relays - Tutorial 1

Objective

Getting familiar with models related to fault simulation.

Getting familiar with different CT models.

T1.1 Create a new case by using either the Menu or Toolbar . A new case should appear
in the Workspace settings entitled noname [psc] . Right-click on this Workspace settings
entry and select Save As… and give the case a name.
 NOTE: Do not use any spaces in the name!  
Create a folder called c:……/PscadTraining/Faults. Save the case as case01.psc  

T1.2 Open the main page of your new case. The single line diagram shown below is a
 part of a substation feeding a shunt reactor. The reactor is modeled in two parts to enable
a falut at point B, inside the turns. The component data is as shown. (make the
transformer losses zero to limit the number of nodes if using the student version)

Station 115 kV
bus
Short line
#1 #2
RL RRL
0.005 0.1 Ea

115 kV,50 Hz Source E 

L 
Z+ = 1.1Ohms / 88 deg Y-D Transformer  Station 13 .8 kV
Z0 = 2 Ohms / 86 deg Z = 8% bus
Full load loss = 0.3%
No load loss = 0.5%

REACTORS
     L
     I

Ir2 Ir1
B  A
0.0125 0.0125  

You may use the wire mode to connect different components.

T1.3 Build the case in PSCAD and enter the component data.

T1.3 Plot the current IL and the voltage EL.

T1.4 Use the ‘fault component to simulate a phase A to ground falut at location A at 0.1s. 

  38 / 72 
 

Timed
Fault
Logic
 

T1.5 Observe the fault curent, IL. What is the reason for the presence of the initial DC
exponential component?

T1.6 What affects the rate of decay of the DC components. Change the resistance of the
short line to 1 Ohm and observe the results.

T1.7 Does the instant of the fault inception have an effect on the DC offset.?

T1.8 What negative impacts can the DC offset have on the system protection.?

T1.9 Connect the phase A line current at point A to the CT model as shown below. The
CT ratio is 5:400. The CT burden is 0.15 Ohms in series with 0.8mH. Plot the secondary
current and the flux density.

IL1

Burden resistance
1 and 0.1 Ohms  

T1.10  Increase the burden resistance to 4 Ohms and observe the results. Note the half
cycle saturation effects due to the dc offset in the primary current.

T1.11  The reactor is protected by a differential relay scheme. Use the 2-CT model in
PSCAD to connect one phase of the reactor protection scheme.

Ir11

Ir21
 

T1.12 Verify the burden current in the differential CT connection for faults at A and B.

T1.13 Does the impedance of the connection leads have an effect on the results.? How is
this impedance accounted for.?

T1.14 Open the case ftdiff.psc. Check the performance of the differential relay during
transformer energization.

  39 / 72 
 

Faults and Current Transformers and relays - Tutorial 2

Objective:

Getting familiar with models in the ‘Relay’ section of the master library. 

T2.1 Create a new case by using either the Menu or Toolbar . A new case should appear
in the Workspace settings entitled noname [psc] . Right-click on this Workspace settings
entry and select Save As… and give the case a name.
 NOTE: Do not use any spaces in the name!  
Create a folder called c:……/PscadTraining/Faults. Save the case as case02.psc  

T2.2 Open the main page of your new case. Construct the simple two area system shown
in the diagram. The voltage sources are set to 230 kV. The inputs to the page module
‘Relay’ are all real data inputs. 

0.1 0.1
I1
E 8.0 0.08 2.0 0.02

Timed
Fault
 ABC->G Logic

Ic
I1 1 2 3 Ic
Ia Ib Ic Ib
Ib
E 1 Ia Relay Expand this page to view the
Ea Ia relay components
Ea
Ea
 

T2.3 Use the modules in the ‘relay’ section of the master library to construct a simple
distance relay. The different modules are shown below.

  40 / 72 
 

FFTto extract the

fundamental

Mag
(7) 1 Impedance calculation
F FT
Ph EaM
Ea (7) 1 VM
dc EaP EaM VP
F = 60.0 [Hz]
EaP IM Va R
Mag IaM IP X R
(7) 1 IaP I0M I + kI
F FT a 0 N
N/D
Ph IaM I0M I0P X
Ia (7) 1 I0P
376.99 D
dc IaP
F = 60.0 [Hz]

Ia Mag
B (7) 1
F FT
+ Ph I0M
+
IbD + (7) 1
R 21
dc I0P R
F F = 60.0 [Hz]
Ic
X
X
Mho
Ia
Characteistics
Ib
Ic
Ea  

T2.4 Identify the function of each module.

T2.5 Verify the operation of the relay.

  41 / 72 
 

Power Quality

Electric Arc Furnace Model

Prepared by: Wang Pei

Date: February 2007
Revision:
Date:

  42 / 72 
 

Electric arc furnace model

The developed EAF model is based on the non-linear differential equations as outlined in
[1],  which models the non-linear characteristics of the electric arc as pictured in Fig. 1a.
The equations representing the arc voltage (v) to arc current (i) are shown below, where r
is the arc radius:
n dr   k    2
k   r   k  r  dt  
3
1 2      m 2
r 
i  

v 
k    3
i  
m 2

r 

The parameters k i, r and n characterize the arc under a given operating condition. In
reality, this V-I characteristic shows much more “noise” due to the unpredictable and
chaotic nature of the load. Fig. 1b shows a more realistic EAF V-I characteristic.

(a) Ideal (b) Actual

Fig. 1 Ideal and actual V-I characteristic of an EAF

Arc Data Setting:

Parameters k 1  to k 3 can be selected to obtain the EAF settings, such as active power,
reactive power and power factor close to what were measured in the practical system. As
the EAF model is sensitive to the system connected, parameters k 1 to  k 3 may need to be
re-tuned if the system configuration changes. The EAF model is designed to be able to
take the inputs parameters as variables so the optimization routines of PSCAD can be
used to expedite the process.

Modulation Type setting:

The randomness feature of the EAF model is simulated by adding certain sinusoidal and
Gaussian noise. The magnitude/frequency of sinusoidal modulation and the standard

  43 / 72 
 

deviation of Gaussian function can be specified. Each phase can be independently

controlled.

It is important to note that it is impossible to get a simulation case to match the observed
results perfectly due to the nature of the problem. The important thing is to capture the
essential features and the trends of a practical arc furnace.

Reference:
[1] “A Harmonic Domain Computational Package for Non-Linear Problems and its
Application to Electric Arcs,” E. Acha, A. Semlyen, N. Rajakovic. IEEE Transactions on
Power Delivery,Vol 5, No.3, July 1990.

  44 / 72 
 

FACTS DEVICES

Active Filters

Instantaneous Reactive Power Method

Synchronous Reference Frame Method

Prepared by: Dharshana Muthumuni

Date: August 2005
Revision: 2
Date: Feb 16, 2007

  45 / 72 
 

Facts Devices - Tutorial - l

Objective:
Getting familiar with power electronic firing models
Getting familiar with control system building block models
Active filter theory

T14.1 Open the two PSCAD cases provided with the course material. The two cases are:
 Activefilter_SR F .psc
 Activefilter_I RP.psc
They are located in the folder named ‘Active_filter’ 

T14.2  The main loads on both these case produce significant harmonics. Study the
different models used in the control circuit for the variable speed drive in
 Activefilter_I RP.psc .

T14.3 Study the control technique used in both IRP and SRF methods.

T14.4 Study how the current reference PWM is implemented to in the active filter bridge.
What is the function of the interpolated firing pulse module?

0.002
1
2
3
2
4 (1) G11

5
H_on 6 2
6 H (2) G21

ON
6 2
L (3) G31

H_off  6 2
H (4) G41

OFF
6 2
L (5) G51

2
(6) G61
 

Fig.1. Integrated firing pulse module

T14.5 Change the parameters of the filters in the control circuit of the active filter and
see the change in response. Can we use FFT to extract the frequencies of interest?

  46 / 72 
 

PSCAD BASIC TRAINING

Synchronous Machines

Exercises 1 - 2

Prepared by: Dharshana Muthumuni

Date: August 2005
Revision: 2
Date: Feb 16, 2007

  47 / 72 
 

Exercise 1

One machine infinite bus case

E1.1 Open the case case_01_startup.psc.

Timer 
3 Phase
LRR RMS

Timer 
S2M

E 
F 
V  17.32

   F
   I  0  60.0
F 
.
 0 
1 
 C  B    A 
P 
Ef0 Ef
Ef  If 
If 
h 

 A Iffa  A
HydroGener 

B Iffb B
Te

C Iffc C
Tm
w Tm Tm0
W TM

0.495  

E1.2  How do you start the machine as a ‘voltage source’. How do you switch from a
‘voltage source’ to a machine rotating at a fixed speed? How do you enable the rotational
dynamics of the machine ?

E1.3 What are the functions of signals Ef0 and Tm0 of the synchronous machine model.

E1.4 Set the machine initial voltage magnitude to 1.04 pu and the phase to 0.75 rad.

E1.5  Run the case and note the Power and Reactive Power levels at steady state. Also
measure the input torque Tm and the field voltage Ef at steady state.

E1.6 Start the machine in the normal ‘machine’ mode and observe the results. 

E1.7  Use the steady state Tm and Ef values in E5.5 as inputs to Tm and Ef. Start the
machine in the ‘machine’ mode. Observe results.

  48 / 72 
 

Exercise 2

Initializing the machine to a load flow

E2.1 Open the case Gen_Pqini_startmetds_01.psc.

S /H
in out
hold

S2M

Vref0 Vref  3 Phase

Exciter_(AC1A) RMS
VT
Ef0 IT   3
Ef  If 

   F
E 
F     I

 0 
.
 0 
1 
 C  B    A 

Ef  If  VT 3
Ef0 Ef
IT  A Iffa  A
HydroGener 

B Iffb B
Te

C Iffc C
Tm
w Tm Tm0

TM

W Tmstdy
w w Tm
z z
 Hydro Gov 1   Hydro Tur 1
z0 zi
Wref  Wref 
1.0  

E2.2 Make sure the machine is rated at 150 MVA, 17.32 kV. It should be connected to an
infinite bus rated at the same voltage through a transmission line of inductance 0.01 H.

E2.3 Calculate the machine terminal voltage in PU and the phase angle in radians, if the
steady state power and reactive power flow is 54 MW and 27 MVar respectively.

E2.4 Set the machine initial conditions so that the simulation will give the correct steady
state P and Q flow.

E2.5 How are the governor, turbine and the exciter initialized?

E2.6 Start the machine as a source and simulate the case.

E2.7  Start the simulation with the machine in the normal ‘machine’ mode. What
additional initial conditions are to be supplied to the machine?

  49 / 72 
 

PSCAD ESSENTIAL TUTORIALS

Synchronous Machine Application Studies

Prepared by: Dharshana Muthumuni

Date: August 2005
Revision: 2
Date: Feb 16, 2007

  50 / 72 
 

Two area power system:

Twoarea_system.psc

This case shows two hydro generators connected through a tie line. When the system load
changes, the tie line power is determined by the governor droop settings.
Check if the machine inertia affects the results.
Changes the droop settings to see the effects.

Small signal stability:

E x_Smallsignal.psc
E x_Smallsignal_exciter.psc
(The machine parameters and the system parameters are as given in the book, Power
System Stability and Control by Prabha Kundur.
The steady state P and Q values are 0.9 and 0.3 respectively.
The oscillation frequency, upon a small disturbance is around 1 Hz and agrees with the
 Eigen Value calculation.)

These cases illustrate the oscillations in a system when a small disturbance is applied.
The oscillation frequencies are in agreement with frequency domain Eigan value
calculations.
Does machine parameters affect the oscillation frequency?
Does the machine inertia affect the oscillation frequency?
Does the load flow condition effect the oscillation frequency?

Critical clearing time for faults:

E x_fault_exciter.psc
Critical clearing time for this fault is 0.1 if the regulator gain is over 400. For values less
than 400, the system becomes unstable. Try different fault clearing times and exciter
gains to see how they are related.

Power System Stabilizer:

E x_pss_tune.psc
The system shown in this case is unstable if run without a power system stabilizer. Run
the case with a constant field voltage and see if the system is stable. This will verify that
the instability is due to the exciter action.
Can we make the system stable by reducing the exciter gain?
Design a power system stabilizer (PSS) to minimize the speed change upon a disturbance.
Use the optimization method of PSCAD to design the PSS parameters.

  51 / 72 
 

CONVERSION OF LOAD FLOW

DATA FILES 

Direct Conversion of PSS/E Files for PSCAD

Model Building

Prepared by: Pei Wang

Date: Feb. 2006
Revision:

  52 / 72 
 

Conversion of load flow dats files –  Tutorial -1

Direct conversion of PSS/E files

Objectives:

Getting familiar with building large systems in PSCAD

Using E-TRAN to convert PSS/E data files
Guidelines to determine detailed network for EMT study
Validation of developed model

T1.1  Create two cases with E-TRAN for the IEEE 39 bus systems: one using only the
.raw file and the other including the dynamic data .dyr file.
- Practice with the selection of zone/area/bus/proximity/
- Network equivalences
- Manual modifications required for EMT study purpose

Fig. 1.Single line diagram of IEEE 39 bus system

  53 / 72 
 

T1.2 E-TRAN Runtime Library for PSCAD and custom substitution libraries

-  Series components (Tline/Transformer) and shunt components (generator)
-  Use of the sample substitution library

EnabExc
VREF
VCT Enab Vref 

0.0 IEEET1
VS
VS
Ef0
3
EF0 E VT
G EF IF 3IT
Exciter VREF 1 + sT Ef0 Ef  If  1 VT  G Vm
Ef If   A
is loadflow terminal voltage... V 1 + sT
E E
VREF TE Te
0.9972 Volts(pu)
4.1825  Angle(deg) GENROU E
Tm
632.0  / 1.0 Pout(MW)
w Tm
109.911 / 1.0 Qout(MVAR) E
Wpu TM Tm0 G TM0
Initial Conditions from Loadflow
1 + sT
W TM
TM0
IEEEG1
EnabGov
Enab
E Wref 

1.0
WRef   
Fig. 2: Detailed machine mode in the substitution library for EMT study

T1.3 Method to determine the kept system (frequency scan)

Fig. 3 Frequency scan results at interested bus

T1.4 Model verification.
-  Comparison of P, Q, V
-  Short circuit data

  54 / 72 
 

Converting a Solved PSS/E Case to PSCAD for Transient Simulations

Many utilities have their power systems modeled in load flow programs. A great deal of
effort is required to re-enter network data for transient simulation studies in
Electromagnetic Transient (EMT) type programs. This application note describes the use
a new tool that allows for an automated setup of PSCAD simulation cases by directly
importing data from solved PSS/E load flow cases, thus maximizing the simulation
engineer productivity. Some helpful tips are also provided on how to ensure the validity
of the transient study by effectively selecting the size of the subsystem to be simulated in
PSCAD. Some key points addressed here are:

  Direct conversion of the PSS/E file: Basic steps



  E-TRAN Runtime Library for PSCAD and E-TRAN custom substitution libraries


   Network equivalences


  Guidelines to determine the extent of the network to be modeled in detail



  Model validation


  Importing dynamic data from the PSS/E *.dyr file



The IEEE 39-bus system (see Figure 1) is used as the base case to illustrate the PSS/E to
PSCAD conversion process. The IEEE 39-bus system is a standard system used for
testing new power systems simulation methodologies. It was created based on a
simplified model of the New England power system. The 39-bus system has 10
generators, 19 loads, 36 transmission lines and 12 transformers.

The conversion of the system into PSCAD is achieved through E-TRAN, a program
developed by Electranix Corporation. In addition to converting PSS/E data into PSCAD
cases, this program offers many powerful features that could be manipulated by the
simulation engineer to reduce the time spent on a study. The software’s most relevant
features are outlined in this document.

  55 / 72 
 

BUS29
T
E_26_29_1 P = 975.2
Q= 54.56
V= 1.026
230.0 : 230.0
GEN    N
1  A    9
   E
8    G
E V
 .   6   4
   2
   1   9
 .    0
 . BUS28 BUS38
   5   2   1
   5   2   =    A   V T T
  =  =     V
100.0 P,Q
E_26_28_1 E_28_29_1 VBUS38
   P   Q 25.0 E Load

BUS37 BUS26 VBUS29

VBUS37 VBUS26
2  2  1 
 3   5   0 
 0  .  0 
.  0 
T T
1  0  .
GEN 100.0
 0 
E    : 
E_25_26_1 P,Q E_23_24_1
10 2 
 3 
E 
25.0 E Load
L P 
   2
 0 
 .    6
   9  .   5
.  o ,
VBUS28
 0   a Q
   3   3   0 T
   5   6  . BUS25 GEN
 d 
   2   1   1    A   V E_26_27_1
6
  =  =   = 100.0 P,Q BUS24
  VBUS25
   P   Q    V 25.0 E Load    9
2  1 
VBUS24  .   6
   8  .   5
BUS30    1   5   0
   8   3  .
 5   0 
   6   2   1    A   V
.  0 
 0  .
  =
 0 
T   =  = 
VBUS30
2 
 3 
E_2_25_1 T E 
   P   Q    V
VBUS27
 0 
.
1  0  E_16_24_1 L P 
E    :  BUS27  o
 a ,
 Q BUS35
VBUS18 100.0 P,Q
2   d 
 3 
BUS18 25.0 E Load VBUS35
 0 
.
 0  2 
 3 
BUS2 2  1  BUS16  0 
.
 5   0  T 100.0
1  0 
E_17_27_1 P,Q E    : 
VBUS2 VBUS16
.  0 
25.0 E Load
 0  .
 0  T 2 
E_17_18_1 T  3 
E  T E_16_21_1
 0 
T E_3_18_1 T .
 0 
T
L P 
E_2_3_1  o , E_15_16_1 VBUS22
 a Q E_16_19_1
 d  T BUS21 BUS22
E_16_17_1
V 
B  VBUS21 T
BUS3  U BUS15
E_21_22_1
T
 S 
1  BUS17 100.0 P,Q BUS19
VBUS3 VBUS15 E_22_23_1
25.0 E Load
2  1  7 
100.0
 5   0 
P,Q
VBUS19
.  0 
25.0 E Load
 0  .
 0 
E  T BUS23
L P  E_3_4_1 T 2 
 3 
2 
 3  2  1 
E_14_15_1
 5   0 
T
 o  0   0 
 a ,
 Q .  0 
VBUS23
. .  0  .
E_1_2_1  d  1  0  1  0   0 
E    :  E    : 
T 2  2  E 
E_4_14_1
 3   3  2 
L P   3 
BUS4
 0   0 
. .  o  0 
 0   0   a ,
 Q .
1  0 
100.0 P,Q BUS14
 d 
E    : 
VBUS4
25.0 E Load 2 
VBUS14
 3 
BUS20 BUS33
 0 
.
 0 
T
E_4_5_1 Load E   25.0
P,Q 100.0 VBUS20    4   8 VBUS33
 .  .   7 BUS36
   2   3   0    9
   6   3   0
 .
   6   1   1  .   5
   7  .    1
   A   V    3   1   8
VBUS36
2 
  =  =    =    7   0   6
 3 
   5   1   0
 .    A   V
 0 
   P   Q   V   =  =     0
.
1  0 
BUS5
   P   Q  =
E    : 

GEN    V
2 
 3 
BUS1 VBUS5  0 
4 GEN
E 
.
 0 
<  7
VBUS1
-
L  T -
i   - 1 
n L  0 
 e i  
n
1   e 0 
-- T BUS34
E_13_14_1
> 
VBUS34
BUS6  .    5
   2  .   8
   5   4   1
BUS12    3   6   0
 .
   5   1   1    A   V
T VBUS6   =  =    =
T 100.0 P,Q    P   Q
E_1_39_1 VBUS12    V
E_5_8_1 T 25.0 E Load
E_6_7_1
2  2  GEN
T 5
 3   3 
 0   0 
E_6_11_1 .
1  0 
.
1  0 
BUS7 E    :  E    : 
2  2 
2  1   3   3 
 5   0   0   0 
VBUS39 .  0  2  .
 0  .
 0 
 0 
T
.  3 
BUS39
 0   0 
E_7_8_1
 .   2
   8
.
 .   9
E  1  0 
   3   4   2
E    : 
   4   1   0
 .
L P 
   7   1   1    A   V
 o
 a ,
 Q
2 
 3  BUS11 BUS13
  =  =
2  1 
    = BUS8
 5   0   d   0  E  E 
   P   Q
.  0  .
   V VBUS13
 0   0 
.
 0  <  < 
VBUS8 VBUS11
2  1  - -
E   5   0  L  T - L  T -
i   - 1  i   - 1 
.  0 
 0  n L  0  n L  0 
T
L P  .  e i  
n  e i  
n
 0  1   e  0  1   e  0 
GEN
 o
 a , E_9_39_1
 Q -- --
1 BUS31
 d  E  >  > 
T L P 
E_8_9_1  o
 a ,
VBUS31
 Q 2  1 
 d   5   0 
.  0 
 0 
.
BUS10
 0 
E 

BUS9
L P 
 o VBUS10
 a ,
 Q 2 
 3 
 d   0 
VBUS9 .
1  0 
E    : 
2 
 3 
   7   7   1
 .  .
 0 
   9   5   6
.
   9
 0 
   2   3   9
   5   2  .    A   V
   0
  =  =    = BUS32
   P   Q    8
   V  .   8
   9  .    1
   7   6
   9   2   9 VBUS32
GEN    6   2   9
 .
   0    A   V
2   =  =    =
   P   Q
   V
Slack Bus
GEN
3
 

Figure 1 Single line diagram of the IEEE 39 bus system in PSCAD

Converting the base PSS/E Case to PSCAD

When converting a case from the PSS/E load flow data file (*.raw) and dynamic data file
(*.dyr), E-TRAN allows for several options that provide enhanced flexibility to the final
user.

To convert the *.raw/*.dyr files, start the E-TRAN program. The pop-up dialog will
 prompt the user through the conversion steps (see ¡Error! No se encuentra el origen de
la referencia. ). The user will have to specify the location of the *.raw/*dyr data files and
the target *.psc file. In the next dialog, the user will specify if the entire network is to be
‘kept’ or if only a specific part is kept and the rest equivalenced. In most transient studies
there is no added benefit in modeling the details of the network beyond a few buses away
from the location of main interest. E-TRAN allows for the system to be partially or fully
converted (all its nodes) into PSCAD.

  56 / 72 
 

Figure 2 E-TRAN dialog boxes

The conversion process will generate a PSCAD (*.psc) file in the specified location. The
network equivalent sources will have their magnitudes and phase angles automatically set
for the same power flow as in the original PSS/E file.

  57 / 72 
 

E-TRAN Runtime Library for PSCAD

The E-TRAN Runtime Substitution Library (see Figure 3)  contains a series of models
specially developed for PSS/E-PSCAD conversions that translates PSS/E component
information into equivalent PSCAD component information. The E-TRAN Runtime
Substitution Library is provided with the program and contains the models that will
appear in the converted PSCAD case. To run the converted PSCAD case:

  Open PSCAD


  Load the E-TRAN Runtime substitution library



  Load the PSCAD case



  Verify the load flow results



Figure 3 E-TRAN Runtime library for PSCAD

Custom Substitution Libraries and data entry

Load flow programs represent the power system network using simplified models
consisting of resistances, inductances and capacitances. When converted to a PSCAD
case, these components can be replaced by more detailed models to represent the
respective unit. Therefore, depending on the user needs, some of the models
automatically substituted from the E-TRAN substitution library may require additional
data or may have to be replaced by more complex models from the PSCAD master

  58 / 72 
 

library. Fortunately, E-TRAN allows the user to create a user substitution library where
any additional information will have to be entered by the users only once, when the
component is used the first time.

An example that calls for the use of the custom substitution library could be a
transmission line, where the PI section or the Bergeron models used to represent it may
have to be replaced by a more accurate frequency dependant model, which will require
specific information on the tower, conductor and right of way dimensions.

In the custom substitution library the user can predefine the substitution of a specific
system component to be done with a pre-filled out PSCAD master library component (or
a user built component) by referencing to the bus number they are connected to (see
Figure 4) 

E
~
Source1

Syncronous m achine
at bus 159

T
B_456_ B_822_T1

 A detailed frequency dependant TLine

From bus 45 6 to bus 822, Circuit T1  

Figure 4 Examples of ‘custom substitution library’ components 

“You can save detailed device data in this library, and E -TRAN will use this data (substituting it for the simple load
 flow data) every time a region of the network is converted into PSCAD. The goal is to eventually have all detailed
model data entered into this library. Once this is achieved, this library can be used to generate PSCAD cases for any
location of your system.

The models in the Substitution Library can also be custom written components, or even page components. A page
component can also have as many layers of sub-pages as required. Each page can also contain sliders, plots, graphs,
control-panels etc... When E-TRAN copies the data from your Substitution Library, it will also replace initial condition
information. For example, E-TRAN will modify synchronous machine data to replace the data for the terminal voltage,
angle, P and Q.” 

The construction of the custom library will require a significant investment of time for
large networks. However, once it is completed, you can convert any part of your network
without having to do any manual data entry. This was identified as a key time saving
feature by large utilities and consultants who are required to work on different parts of
large networks when undertaking different projects.

  59 / 72 
 

Deciding on the Part of the Network to be Kept

A transient study would require the detailed modeling of a small part of the network
around the main point of interest. Typically, this would be about 2 or 3 buses away from
this point. E-TRAN allows the users to efficiently decide and check if the ‘kept’ network
details are adequate for a given study. The following steps are recommended. This makes
use of the ‘network frequency scan’ component of PSCAD (see Figure 5).

  Convert the PSS/E file to PSCAD, keeping the details 2 or 3 buses away from the
main point of interest and equivalencing the rest.

  Use the frequency scan component of PSCAD to plot the impedance vs.
frequency characteristic of this system at the bus concerned.

  Reconvert the PSS/E file, this time, keeping the details of one more bus away
than in the earlier step.

  Plot the impedance vs. frequency characteristics of this system at the bus
concerned and compare with the first plot.

  Repeat the process until the differences in frequency characteristics are minor in
the frequency range of interest. Adding more details of the network beyond this
 point is unlikely to improve results.

Z(f)

0.0 -
2000 [Hz]
 

Figure 5 PSCAD Frequency Scan component

  60 / 72 
 

Figure 6 Frequency scans 2, 3, … 6 buses away at bus No. 15 for the system under study 

Figure 6 shows the use of the frequency scan feature. Here different network equivalents
were constructed using E-TRAN for the IEEE 39 bus system at bus No. 15 for 2, 3, … 6
 buses away (with 6 buses away comprising the whole network). These network
equivalents were created using the load flow data file only (*.raw). It can be observed
that the frequency spectrums of the equivalent networks start providing a good
approximation for the whole network starting at ‘4 buses away’. 

Validation
A quick method to validate the simplified equivalent system provided by E-TRAN is to
compare the values calculated by PSCAD for node voltages, transmission line load flows
or P, Q flows at generation busses with the ones previously calculated by PSS/E. For
such purpose, use the multi-meter to display the voltage at the node of concern and the P
and Q flows in the respective transmission line. Then, display the same information for
such node in the PSS/E load flow utility. The converted PSCAD case will have auto
generated labels that display the P, Q flows at generation buses. Figure 7 shows the
PSS/E and PSCAD results for the voltage magnitude and angle at node 15 as well as the
P and Q flows for the nodes 15 to 16 transmission line.

  61 / 72 
 

PSS/E Load Flow output

 BUS 15 LBUS15 345 AREA CKT MW MVAR MVA %I  1.0154PU -7.75 DEG
1 350.31KV
TO 16 LBUS16 345 1 1 -31 4.7 -1 51 .7 349.3  

P1 : ...
V15 Angle

V15_Ang

P = -314.7
-7.74857
Q = -151.7
Z(f) LBUS15 V = 1.015
N15 T
 A E_15_16_1
0.0 - V
2000 [Hz]
 

Figure 7 Comparison of load flow results between PSCAD and PSS/E

Short-circuit level calculation at certain buses for the converted PSCAD case is also
recommended. The short-circuit results can be compared to those from the PSS/E study
or utility system data for validation purpose. Once the PSCAD system has been validated,
it is ready to be used for transient studies.

Importing Dynamic Data from the .dyr File

During the conversion process the user can specify to import dynamic data from the
PSS/E *dyr file. If this option is selected, all generators in the ‘kept’ part of the network
will be replaced by detailed machine models (see Figure 8). The machine controls and
related models (exciter, governor, PSS, turbine) will also be included in the PSCAD
model. All information necessary to initialize these models will either be imported from
the *raw/*dyr files or be computed by E-TRAN. Thus, the simulation will automatically
come to the specific steady state after a few cycles of simulation time.

  62 / 72 
 

EnabExc
VREF
VCT Enab Vref 

0.0 IEEET1
VS
VS
Ef0
3
EF0 E VT
G EF IF 3IT
Exciter VREF 1 + sT Ef0 Ef  If  1 VT  G Vm
Ef If   A
is loadflow terminal voltage... V 1 + sT
E E
VREF TE Te
0.9972 Volts(pu)
4.1825  Angle(deg) GENROU E
Tm
632.0  / 1.0 Pout(MW)
w Tm
109.911 / 1.0 Qout(MVAR) E
Wpu TM Tm0 G TM0
Initial Conditions from Loadflow
1 + sT
W TM
TM0
IEEEG1
EnabGov
Enab
E Wref 

1.0
WRef   

Figure 8 Detailed synchronous machine model automatically generated by E-TRAN with

 parameters taken from the PSS/E *.dyr and *.raw files

  63 / 72 
 

LBUS01 LBUS02 LBUS03 LBUS04

T T T
N1 N2 N3 N4 500.0 P,Q
E_1_2_1 E_2_3_1 E_3_4_1
184.0 E Load
322.0 P,Q
2.4 E Load

LBUS18
T
N18 158.0 P,Q
E_3_18_1
30.0 E Load
LBUS25 LBUS26
T T
N25 N26 139.0 P,Q
E_2_25_1 E_25_26_1
17.0 E Load

224.0 P,Q
47.2 E Load

GBUS37
345.0 : 22.0
N37 540.0 E
1 ~
0.445
E VN37 E_37_0_1
GBUS30
345.0 : 22.0
N30 250.0 E
1 ~ P = 522
146.154
E VN30 E_30_0_1 Q = 176
GBUS39 LBUS09 LBUS08
T T T
N39 N9 N8 522.0 P,Q
E_1_39_1 E_9_39_1 E_8_9_1  A
176.0 E Load
VN39 V
1104.0 P,Q
250.0 E Load
1000.0 E
88.281
~
E_39_0_1  

Figure 9 IEEE 39 bus system converted to PSCAD for bus No. 1 (3 nodes away)

A subsequent validation document will discuss the conversion process in more detail.
This will include a discussion on importing dynamic devices, saturation and comparison
of low frequency transients with transient stability results.

References

[1]  Electranix Corporation “E-TRAN V1.1: Electrical Translation Program for Power
Systems. User’s Manual” February 2003 

Prepared by:

Juan Carlos Garcia

Dharshana Muthumuni

Pei Wang

  64 / 72 
 

PSCAD ADVANCE TRAINING

Tutorial on Creating Custom Components

Prepared by: Dharshana Muthumuni

Date: August 2005
Revision: 2
Date: Feb 16, 2007

  65 / 72 
 

PSCAD Advanced Training - Tutorial 1

Adder

Purpose:
To get familiar with the Component Workshop (or the design editor).
Create input/output nodes.
Get familiar with the graphic, Parameters and the script sections of the editor. 

Create a library file.

Use the component workshop to create a simple control block to do the following
computation.

 K 1  A    K 
  2  B  C  

A and B - External inputs

K1 and K2 –  Internal parameters
C –  Output

Include the component in a case and verify its accuracy

Modify the component so that K1 and K2 can be entered as variables.

Verify the modified component.

 A
 Adder  C
B

  66 / 72 
 

PSCAD Advanced Training - Tutorial 2

Integrator

Purpose:
Calling external subroutines.
 Storing data for computations in following (future) time steps.

The block should perform the following function


 y    xdt  
x –  input
y –  output

To keep things simple, use ‘rectangular integration’. 

 y(t )   y(t   
   t )   x(t )  t   

This will require the storage of ‘past’ value of y. 

Allow for the input of initial value of y.
Use an external FORTRAN Subroutine to do the calculations.

Integrator 

x y

  67 / 72 
 

PSCAD Advanced Training - Tutorial 3

Electrical Component –  Transformer (coupled wires)

Purpose:
 Design an ‘electrical’ component. 
Using ‘branch’ and ‘transformer’ sections of the ‘script’  

Design a model of two magnetically coupled wires.

The model is to be interfaced with other electrical components in the master library.

The inductances and resistances are the inputs.

va   La  Mab d  ia  Ra o  ia

vb   Mab  Lb  dt  ib   o  Rb ib  
        

Use the ‘transformers’ section to enter the L and R values. 

Connect the model to a source and verify the model.

a1 a2

b1 b2
Two coupled
wires with capacitance  

Use the ‘Branch’ section to add ‘stray capacitance’ between the wires on the input side.

  68 / 72 
 

PSCAD Advanced Training - Tutorial 4

Electrical Component –  A simple DC Machine

Purpose:
I nterface an electric component as a voltage source. (Branch based interface) 

Design a simple model of a DC machine.

Field circuit - Series L and R

Armature circuit –  A series branch of L, R and a voltage source of magnitude Eb.

 Eb  k    _   w  

w   speed   
150
k  _  
  
1  e if  / kf    
188.5
if –  Field current
kf –  Input parameter (constant)
The inductances and resistances are the other inputs.

f1 f2
a1
Simple
DC Machine
a2

w
 

  69 / 72 
 

FORTRAN CODES
Integrator:
!
SUBROUTINE INTEGRATOR(x,y,YINI)
!
! Purpose - integration of a real signal
! Language - Fortran 77/90
! Date -
! Author -
!
! Include Files
! -------------
INCLUDE 'nd.h'
INCLUDE 's1.h'
INCLUDE 'emtstor.h'
!
! Variable Declarations
! ---------------------
REAL x,y,YINI
REAL YOLD
INTEGER ISTORF
!
! Program begins
! --------------
! ISTORF = NSTORF
 NSTORF = NSTORF + 1
! it is good to assign NSTORF to ISTORF and
! have all the user assigned STORx locations at the
! top, then you can even use the other functions
! available in EMTDC in your code without worrying
! about which STORx locations are
! used by them
YOLD = STORF(ISTORF)
! here NSTORF points to the first STORF location
! used in the routine, in the old method in V2, NEXC
! pointed to the last STOR location in the previously
! called subroutine/function.
Y = x*DELT + YOLD
! output at time zero
IF (TIMEZERO) THEN
Y = YINI
ENDIF
! save the data for next time step
STORF(ISTORF) = y
!
RETURN
END

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Simple DC Machine:

SUBROUTINE SIMPLEDC(Kf,w,A1A2,F1F2,SS)
!
! Dharshana : 04 Aug 2002
!
INCLUDE 'nd.h'
INCLUDE 's0.h'
INCLUDE 's1.h'
INCLUDE 's2.h'
INCLUDE 'branches.h'

REAL Kf,Ifld,w,k_pi
INTEGER A1A2,F1F2,SS

! Activate the source on branch A1A2

SOURCE(A1A2,SS)=.TRUE.

!
! Read the field current and the armature current during the previous time step

Ifld=CBR(F1F2,SS)*1000

!
! Define the noload excitation charactersitics for the machine
!
k_pi = (150/188.5)*(1 -EXP(-Ifld/Kf))
!
EBR(A1A2,SS)=-k_pi*w/1000
!

RETURN
END
!

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