LCOE

Metrology for future HV transmission:

HV measuring techniques:
Course &workshop, 24 May 2023

Rev.2
1
 LCOE

 New IEC 60060-1 Ed 4: High-voltage test

techniques: General definitions and test
requirements.

Committee draft for vote (CDV). 2023/03/24

 New IEC 60060-2 Ed 4: High-voltage test

techniques: Measuring systems

Committee draft for vote (CDV). 2023/04/21.

Rev.2
2
 LCOE

TC2 TC14 TC17 TC20 TC33 TC36 TC37 TC38

Rotating Power Switchgear Cables Capacitors Insulators Surge Instrument
machines Transformers Arresters transformers
TC1
Terminology
TC28
Insulation
coordination
TC42 Horizontal standards: IEC
HV, HC Test
techniques 60060-1, 60060-2, 60060-3,
TC 77 60270
Electromagnetic
compatibility
TC 104
Environmental
conditions
TC 115 HVDC
Transmission

Rev.2
3
 LCOE

TC of interest IEC 60060-1 IEC 60060-2

TC 14. Power Transformers
TC17. High-voltage switchgear and
controlgear.
SC 17A. Switching devices
SC 17C. Assemblies
SC 18 A. Electric cables for ships and
mobile and fixed offshore units
TC 23. Electrical accessories
TC 32. Fuses
TC 36. Insulators
TC 37. Surge arresters
TC 38. Instruments transformers.
TC 122. UHV AC transmission systems

Rev.2
4
 LCOE

New IEC 60060-1 Ed 4

Rev.2
5
 LCOE

New IEC 60060-1 Ed 4: High-voltage test

techniques: General definitions and test
requirements.

• Tests with DC, AC, SI, LI, test voltage definitions

• Tests with combined or composite voltages
• Test procedures
• Atmospheric corrections for dry tests

Changes will be addressed (in red)

Rev.2
6
 LCOE
Tests with direct voltages

Ripple frequency: mains supply or electronic converter

(chopper)

Rev.2
7
 LCOE Tests with alternating voltages
200
Peak,1 + Peak,2 + Peak,i +
150 Voltage dips (for wet or pollution
100 test) in case of transient discharges
50 < 10%
0 (before <20%).
-50 Voltage dips > 10%, accepted if
-100
they do not affect test results.
-150
Peak,2 - Peak,i -
-200 T, test duration
-250
0,000 0,010 0,020 0,030 0,040 0,050 0,060 0,070 0,080 0,090 0,100 0,110 0,120
Time (ms)

,, ,,

WAVE SHAPE,
SPECIFICATION:

,, ,,

Rev.2
8
 LCOE Tests with alternating voltages
200
Peak,1 + Peak,2 + Peak,i +
150

RMS value is used when 100

thermal effects are involved, 50
for instance, temperature rise 0
tests
-50

-100

-150
Peak,2 - Peak,i -
-200 T, test duration
-250
0,000 0,010 0,020 0,030 0,040 0,050 0,060 0,070 0,080 0,090 0,100 0,110 0,120
Time (ms)

TEST VOLTAGE
MISTAKE:

Rev.2
9
 LCOE Tests with LI voltages
Manual calculation
procedure in Annex C
(informative)

𝒕 𝒃 𝒆 𝒃)

Base curve, fitted to the recorded curve Parameters Ut, T1, T2, calculated
from 0,2 Ue (front) to 0,4 Ue (tail) using the Test voltage curve, not
the recorded curve

Filter transfer
function for
the residual
curve

Residual curve is filtered with the test voltage function.

Test voltage curve is the addition of the base curve and the filtered residual curve
Rev.2
10
 LCOE Tests with LI voltages

Test voltage curve, after

filtering process

Parameters Ut, T1, T2, calculated using the Test voltage curve, not the
recorded curve

Rev.2
11
 LCOE Tests with SI voltages

Old definition:
Tp / T2 = 250/2500

New:
T1 / T2 = 170/2500

Tp T2

Same definition as for LI front time.

Parameters calculated using the
recorded curve

Rev.2
12
 LCOE Combined voltages

Ut = U1-U2
3 terminal object under test, such as disconnectors or phase
AC+LI, AC+SI
to phase insulation of a three-phase system equipment
DC+LI; DC+SI
2- channel recorder

Rev.2
13
 LCOE Composited voltages

2 terminal object under test, one terminal connected to earth. Ut = U1+U2

3 channel recorder
USE UNIVERSAL DIVIDER (see IEC 60060-2) AC+LI, AC+SI
DC+LI; DC+SI

Rev.2
14
 LCOE

Uncertainty of atmospheric parameters for

correction factor calculation (k1,air density
and k2,humidity) for air gaps

Absolute humidity, U ≤ 1 g/m3

Temperature, U≤1K
Absolute pressure, U ≤ 5 hPa (before 2 hPa)

Rev.2
15
 LCOE

Wet tests: precipitation requirements

tolerances are enlarged for Um> 550 kV

New

Rev.2
16
 LCOE

Difference between

Tolerance (IEC 60060-1)

and

Uncertainty (IEC 60060-2)

Rev.2
17
 LCOE
Tolerance:
Permitted difference between the measured value and the
specified value.
Example:
Specified withstand voltage: 125 kV
Reading of the measuring instrument: 126,5 kV
Difference = +1,2% < 3% (Tolerance)

Uncertainty (of measurement)

Parameter, associated with the result of a measurement,
that characterises the dispersion of the values that could
reasonably be attributed to the measurand.
Example:
Voltage measurement: 126,5 kV ± 3,8 kV
(for a coverage probability of not less than 95%,k=2)

Rev.2
18
 LCOE
Specified tolerances

Parameter Duration or DCV ACV LI SI Combined,

voltage composite

Test voltage Test ≤ 60 s ± 1% ± 1%

Test voltage Test > 60 s ± 3% ± 3%
Test voltage ± 3% ± 3% ± 5%
T1 Um ≤ 800 kV ± 30% ± 20%
T1 Um > 800 kV - 30%,+100% ± 20%
T2 ± 20% ± 60%
b´ (overshoot) <10% Ue
Time delay, Dt (*)

(*) whichever is longer [±5% of T1 of an impulse; ±5% of the quarter of a cycle of ACV]

Rev.2
19
 LCOE

((Measuring systems))

Rev.2
20
 LCOE Measuring systems

Definition: complete set of devices for performing HV measurement, included the

software.

1. Converting device (HV divider).

2. Transmission system (cable) of Z impedance.
3. Digital recorder, or digital multimeter
In some cases
- Terminal impedance, or attenuators.
- Software

Rev.2
21
 LCOE Measuring systems

Calibration recommendations

 Calibration of the full measuring

system, not only the divider.

 Due to large size of equipment

and the real environmental
conditions the calibration should
be performed on site.

Rev.2
22
 LCOE
HV dividers

Parallel
High Low Series mixed
ohmic ohmic damped resistor-
resistive resistive Capacitive capacitive capacitive Universal
dividers dividers dividers dividers dividers dividers
DC LI AC, SI AC, LI, SI AC, LI, SI DC, AC,LI, SI

HV arm

LV arm

Rev.2
23
 LCOE HV dividers: stray capacitances
affect SF, and dynamic behaviour

Rev.2
24
 LCOE

High ohmic resistor dividers

DC AC SI LI
High ohmic divider ++ + + -

Stray capacitances combined with high value resistances produce

response time too big, and poor dynamic behaviour, therefore
limited use when increasing frequency.

Rev.2
25
 LCOE
High ohmic resistor dividers

i ≥ 0,5 mA i ≥ 0,5 mA →R1 ≤ 200 MW /100 kV

To ensure that the influence of leakage current is negligible,
current as high as 0,5 mA at the rated voltage can be necessary.
HV arm R1

DMM or digital Input resistance of DMM

recorder
or recorder can changed
LV arm Rter RDMM
R2 with the measuring range
¿1 MW, 10 MW, and affects the scale
10 GW, 1TW?
factor.

Termination resistor,
if needed, for
instance 1,111 MW

Rev.2
26
 LCOE
High ohmic DCV divider: example o the
influence of DMM input resistance in the DCV
scale factor in a Fluke commercial probe

R(DMM) FS
1,000 MW 1899,19
10,00 MW 1000,09
10,20 MW 998,131
10,00 GW 900,290
1,000 TW 900,191

999 MW 1,111 MW

Rev.2
27
 LCOE Low ohmic resistor dividers

DC AC SI LI
Low ohmic divider - - - ++

 R1 in the range of 1 to 20 kW to
reduce response time
HV arm Equivalent
 Inductance should be minimized
Stray
(bifilar windings) capacitance
 Not appropriated to measure SI,
AC or DC due to heat dissipation
involved.
 Limitations for voltages > 800 kV LV arm

Rev.2
28
 LCOE Low ohmic resistor dividers

 Shielding of divider by means of rings to produce linear

distribution of electrical field

Rev.2
29
 LCOE Capacitive HV dividers

DC AC SI LI
Capacitive HV dividers - ++ ++ (*) possible with damping
resistor, Rd

 DC measurements impossible.

Rev.2
30
 LCOE Capacitive HV dividers

Equivalent circuit:
Capacitors C´ with stray
elements (R´, L´, C´p and C´e),
see [1]

 Capacitive dividers overcome the problem of heat dissipation of R dividers.

 Used up to MV range

 Not suited for LI because network (L´.C´) produces oscillations in the MHz range,
also reflections between top and bottom of the divider produce oscillations.
 With Rd of 300 W ... 600 W, oscillations reduced and LI measurements possible.

Rev.2
31
 LCOE Capacitive HV dividers:
equivalent circuit

HV arm Equivalent
Stray
1 capacitance

LV arm
2 2

 Apparently FS is the same for low and high frequencies.

 Actually, inductances and resistances L´, R´, must be taken into account in an
extended equivalent circuit and dynamic behaviour if frequency dependent.
 Shielded standard capacitors can be used to avoid stray earth capacitances.
Rev.2
32
 LCOE Series-damped capacitive HV dividers

DC AC SI LI
Series-damped capacitive HV dividers - + ++ ++

 DC measurements impossible. “Zaengl” divider

 Able to measure composited voltages (AC+LI, AC+SI)
 Real resistances (non parasitic) in series with
capacitances
 Resistance avoid oscillations of pure capacitive dividers.
 Good dynamic behaviour with lower loading of the test R
circuit than resistive dividers

( ) ( )
2

Rev.2
33
 LCOE Resistive-capacitive mixed HV dividers

DC AC SI LI
Resistive-capacitive mixed HV dividers + + ++ ++

 SF and rated voltage for the different

waveshapes are usually different.
R
 The divider represents a high load on
the generator. (LI, DCV)

 Evolution of resistive divider for LI,

where C´1 are real capacitors 2 R

Rev.2
34
 LCOE
Resistive-capacitive mixed
HV dividers
 Evolution of resistive divider
1. Resistive-capacitive
for LI, where C´1 are real mixed HV divider.
capacitors 2. Transmission system
 The Ce effect is reduced if (cable) of Z surge
C´1 are increased. impedance and
capacitance Ck
 Design condition C´1> 3Ce 3. Digital recorder.
→ C´1 is too large
 Change (step) of the SF with
frequency due to Ce
 Due to the manufacturing
cost of the additional
capacitive part has lost on
importance in comparison
with damped series-
capacitance divider

Rev.2
35
 LCOE Universal HV dividers

DC AC SI LI
Universal HV dividers ++ ++ ++ ++

 Evolution of series-damped
capacitive divider adding high
value resistances RDC in R𝑑1
parallel with C1 and C2.

 Able to measure DC RDC1

 SF equal for all waveshapes

inside ± 3% R𝑑2
(New: IEC 60060-2) RDC2
2
Equivalent circuit of Universal dividers
according to Simon Boonants, “Testing an
analysis of universal HV divider” [4]

Rev.2
36
 LCOE Universal HV dividers

( ) ( )
R𝑑1
( ) ( )
RDC1

R𝑑2
RDC2
2

Rev.2
37
 LCOE
R𝑑1𝑒𝑥𝑡 130 Ω

HV arm
Universal HV
R𝑑1𝑖𝑛𝑡
120 Ω dividers
RDC1
600 MW 825 𝑝𝐹
Rter
50 W Rdigitizer
RDC2, f
R𝑑2 1 MW
1,4 MW
LV arm 250 𝑚Ω

RDC2, v 2
840 𝑛𝐹
0.. 50 kW

Universal divider circuit diagram designed by VTT MIKES (Finlad), from

Simon Boonants, “Testing an analysis of universal HV divider” [4]

Rev.2
38
 LCOE

New IEC 60060-2 Ed 4

Rev.2
39
 LCOE

New IEC 60060-2 Ed 4: High-voltage test

techniques: Measuring systems.

• Methods to determine uncertainties of HV

measurements.
• Requirements for HV measuring systems.
• Methods for approving measuring systems and
checking of its components
• Uncertainty of measuring systems.

Changes will be addressed (in red)

Rev.2
40
 LCOE

Reference measuring

Uncertainty of measurement
systems of low uncertainty
Traceability chain

for calibration (TRMS)

increases
Reference measuring systems for
calibration or testing (RMS)

Approved measuring systems for HV

testing (AMS)

Rev.2
41
 LCOE Test required for DC, DC (ripple), AC, LI
and SI, RMS, are specified in the standard

Example for ACV, AMS

Periodic intermediate checks

Note: for LI
performance

calibration
checks
include also
dynamic
behaviour and
interference
tests

Rev.2
42
 LCOE Calibration procedures for AMS

a) Comparison
over the full
voltage range

5 or more voltage
levels)

Rev.2
43
 LCOE Calibration procedures for AMS

b) Comparison over
limited voltage range

linearity test

- Input voltage of
the HV generator.
- Electric field
probe.
- Standard air gap
according
IEC60502

Rev.2
44
 LCOE
Uncertainty contributions using a HV
measuring system

 Calibration uncertainty of the scale factor, (SF),

 Non linearity of the SF, determined in the calibration
 Non linearity of the SF, if not calibrated the full range,
 Dynamic behaviour,
 Short-term stability (self heating),
 Long-term stability,
 Ambient temperature effect,
 Proximity effect,
 Software effect,

Rev.2
45
 LCOE Dynamic behaviour of ACV, AMS

f1 = 50 Hz, f2= 60 Hz

At f=420 Hz, attenuation is 0,1dB →

G(420 Hz) = 0,9885 pu

Rev.2
46
 LCOE Interference test for LI

It is a performance test and a performance check.

Maximum amplitude of interference < 1% Test voltage

Rev.2
47
 LCOE Uncertainty of Approved
measuring systems (AMS)

DCV ACV LI SI Combined Composite

Test voltage 3% 3% 3% 3% 5% 5%
Ripple (*) 10% d; 1%Ut
Peak voltage 5%
(front chopped LI)
Voltage change 3%
T1 (**) 15% 10%
T2 10% 10%
Tc (***) 15%
Time delay, Dt 10 ms 10 ms

(*) whichever is larger [10% d; 1%Ut ]

(**) Before 10%
(***) same uncertainty as for T1, even not indicated in the standard

Rev.2
48
 LCOE

Uncertainty of Reference measuring systems

(RMS)

DCV ACV LI SI
Test voltage 1% 1% 1% 1%
Peak voltage 3%
(front chopped LI)

T1 5% 5%
T2 5% 5%
Tc 5%

Rev.2
49
 LCOE
Dynamic behaviour of measuring systems for LI, SI, by means of step
response

For AMS,
Step response
= reference
level ± 2%

Recommendations
for RMS parameters

Rev.2
50
 LCOE

Uncertainty of Reference measuring systems o low

uncertainty, (TRMS)

DCV ACV LI SI
Test voltage 0,5 % 0,5 % 0,5 % 0,5 %
T1 3% 3%
T2 3% 3%
Tc 3%

Rev.2
51
 LCOE Bibliography
[1] E. Kuffel, W. S. Zaengl, and J. Kuffel, ‘Chapter 3 - Measurement of high
voltages’, in High Voltage Engineering Fundamentals (Second Edition), E.
Kuffel, W. S. Zaengl, and J. Kuffel, Eds. Oxford: Newnes, 2000, pp. 77–200.
doi: 10.1016/B978-075063634-6/50004-6.

[2] K. Schon, High Impulse Voltage and Current Measurement Techniques.

Hei-delberg: Springer International Publishing, 2013. doi: 10.1007/978-3-319-
00378-8.

[3] W. Hauschild and E. Lemke, High-Voltage Test and Measuring Techniques.

Cham: Springer International Publishing, 2019. doi: 10.1007/978-3-319-97460-
6.

[4] Simon Boonants, Testing and Analysis of Universal High Voltage divider,
Master of Science Thesis, Faculty of Information Technology and
Communication Sciences. May 2022.

[5] 42/414/CDV. 60060-1. 2023/03/24

[6] 42/416/CDV. 60060-2. 2023/04/21

Rev.2
52