Exercise 1
Creation of Power Flow Data Files
Objective:
The objective of this exercise is to introduce PSS/E (Power System Simulator for
Engineering). At the end of this exercise, you will learn how to create PSS/E power flow data
files: the raw data file that contain basic system data and the slider binary file that is used to
draw the single line diagram corresponding to the entered system data.
Required Background:
A good understanding of the steady state models of generators, power transformers and
transmission lines, per unit system, and basic formulation of power flow problem.
9-bus Power System [1]
The simple power system used as an example in this exercise has nine buses, three generators
and three loads. A single line diagram of the system is given in Fig.1. The bus data and
branch/transformer data are given in Tables 1 and 2 respectively.
Fig. 1 : Single line diagram of the 9-bus test system
PSS/E Training Course – Exercise 1 1
Table 1 : Bus data
Nominal voltage Specified voltage Generation Load
Bus # Bus type
(kV) (pu) (MW) (MW) (MVar)
1 Slack 16.5 1.040
2 PV 18.0 1.025 163.0
3 PV 13.8 1.025 85.0
4 PQ 230.0
5 PQ 230.0 125.0 50.0
6 PQ 230.0 90.0 30.0
7 PQ 345.0
8 PQ 345.0 100.0 35.0
9 PQ 22.0
Table 2 : Branch/Transformer data (100 MVA base)
From Bus To Bus R (pu) X (pu) B (pu) Rating (MVA)
1 4 0.0576 247.5
2 7 0.0625 192.0
3 9 0.0586 128.0
4 5 0.010 0.085 0.176 100.0
4 6 0.017 0.092 0.158 50.0
5 7 0.032 0.161 0.306 125.0
6 9 0.039 0.170 0.358 100.0
7 8 0.0085 0.072 0.149 120.0
8 9 0.0119 0.1008 0.209 50.0
Procedure:
Follow the steps given below to create new PSS/E case corresponding to the 9-bus system
given above, enter system data and create a single line diagram.
Step 1: Start the program
Start → All programs → Siemens PTI → PSSE33 → PSSE®E 33
(Alternately you can use the short cut icon on the desktop)
Step 2: Set the system frequency
Misc → Change program settings (Fig. 2) → Base frequency → Set to ’50 Hz’
(Fig. 3) → Ok
Fig. 2 : Change program settings
PSS/E Training Course – Exercise 1 2
Fig. 3 : Program settings dialog
Step 3: Create a new case
File → New → Select Network Case and Diagram (Fig. 4) → Ok
Fig. 4 : New case dialog
Enter MVA base (‘100 MVA’) and case heading (‘9_Bus_system’) (Fig. 5)
Fig. 5 : Build new case dialog
Step 4: To enter system data using the worksheet interface select network data tab (Fig. 6)
Fig. 6 : Network data
There are 19 subtabs to choose from at the bottom of the network data tab. The most
import subtabs are described in Step 5 - 10.
PSS/E Training Course – Exercise 1 3
Step 5: Bus subtab
Inside the Bus tab there are several parameters that can be set (Fig. 7).
Enter bus data given in Table 1
Bus type code:
1 – Load bus (PQ bus)
2 – Generator bus (PV bus)
3 – Swing bus (Slack bus)
Fig. 7 : Bus data
Step 6: Plant subtab
The plant tab is used to add power plants and set their terminal voltages (Fig. 8).
Set specified voltages and remote controlled buses (if any) for G1, G2 & G3
Fig. 8 : Plant data
Step 7: Machine subtab
The machine tab is used to add machines at an existing plant (Fig. 9).
Enter PGen values for G2 & G3
PSS/E Training Course – Exercise 1 4
Fig. 9 : Machine data
Step 8: Load subtab
The load tab is used to enter the load data records (Fig. 10).
Enter load values (both P & Q) for PQ buses (buses 5, 6 & 8)
Fig. 10 : Load data
Step 9: Branch subtab
The branch tab is used to enter transmission line parameters.
Enter transmission line parameters (R, X & B) given in Table 2 (Fig. 11).
Fig. 11 : Branch data
Note – When entering line parameters a message popups and displays “Info: Branch
is no longer treated as a zero impedance line”. Press Ok to close the message.
Zero impedance lines are used to model bus ties, jumpers, couplers or breakers.
PSS/E Training Course – Exercise 1 5
Fig. 12 : Zero impedance line warning message
Step 10: 2 Winding subtab
The 2 winding transformer tab maintains the transformer data (Fig. 13).
Enter 2 winding transformer data given in Table 2
Fig. 13 : Zero impedance line
Step 11: Save data to a .raw file
File → Save → Select Power Flow Raw Data tab → Provide a data file name
(‘9_Bus_System_Ex1.raw’) → Ok (Fig. 14)
Fig. 14 : Save network data dialog
PSS/E Training Course – Exercise 1 6
Step 12: Create a single line diagram (Fig. 15) using auto draw function and save it to a .sld
file using the following steps.
Click on Auto draw icon → enter selected bus (‘bus 2’) → Grow N levels (‘4’) →
Ok (Fig. 16)
Fig. 15 : Diagram data
Fig. 16 : Select bus for auto-draw dialog
Shape up the diagram by moving the components to appropriate locations (Fig. 17)
Fig. 17 : Single line diagram view
Step 13: Save the diagram
File → Save → Provide a single line file name (‘9_Bus_System_Ex1.sld’) → Ok
Step 14: Check whether you can view/edit the data of individual components in the single
diagram view.
References
[1] P. M. Anderson and A. A. Fouad, power system control and stability, 2nd Edition. A John
Wiley & Sons, Inc., USA, 2003.
PSS/E Training Course – Exercise 1 7
