IEC TR 60919-1:2010/AMD1:2013

IEC/TR 60919-1 ®
Edition 3.0 2013-04
TECHNICAL
REPORT
AMENDMENT 1
Performance of high-voltage direct current (HVDC) systems with line-
commutated converters –
Part 1: Steady-state conditions

IEC/TR 60919-1:2010/A1:2013(E)

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IEC/TR 60919-1 ®
Edition 3.0 2013-04
TECHNICAL
REPORT
AMENDMENT 1
Performance of high-voltage direct current (HVDC) systems with line-

commutated converters –
Part 1: Steady-state conditions

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
Q
ICS 29.200; 29.240.99 ISBN 978-2-83220-738-3

– 2 – TR 60919-1 Amend. 1  IEC:2013(E)

FOREWORD
This amendment has been prepared by subcommittee 22F: Power electronics for electrical

transmission and distribution systems, of IEC technical committee 22: Power electronic
systems and equipment.
The text of this amendment is based on the following documents:

DTR Report on voting
22F/277/DTR 22F/286A/RVC
Full information on the voting for the approval of this amendment can be found in the report
on voting indicated in the above table.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
A bilingual version of this publication may be issued at a later date.

_____________
CONTENTS
Replace, the titles of Clause 19 and its subclauses as follows:
19 Radio frequency interference
19.1 General
19.2 RFI from HVDC systems
19.2.1 RFI sources
19.2.2 RFI propagation
19.2.3 RFI characteristics
19.3 RFI performance specification
19.3.1 RFI risk assessment
19.3.2 Specification RFI limit and its verification
19.3.3 Design aspects
Add the title of Annex A as follows:
Annex A (informative) Factors affecting reliability and availability of converter stations
Replace, in the list of figures, the title for Figure 23 as follows:

TR 60919-1 Amend. 1  IEC:2013(E) – 3 –

Figure 23 – RY COM noise meter results averaged – Typical plot of converter noise levels on

the d.c. line corrected and normalized to 3 kHz bandwidth – 0 dBm = 1 mW corresponding to

0,775 V at a pole-to-pole surge impedance of 600 Ω

Add, in the list of figures, the title for Figure 25 as follows:

Figure 25 – Recommended measurement procedure with definition of measuring point

Figure 7 – Bipolar system
Replace Figure 7 by the following new figure:

I
d
(+)
1 1
2 2
F F
U
d
3 3
U
d
2 F F 2
1 (–) 1
IEC  807/13
Key
1 DC reactor
2 DC filter
3 Earth electrodes
Figure 7 – Bipolar system
Figure 10 – Bipolar system with two 12-pulse units in series per pole
Replace Figure 10 by the following new figure:

– 4 – TR 60919-1 Amend. 1  IEC:2013(E)

IEC  808/13
Key
1 DC reactor
2 By-pass switch
3 DC switch
Figure 10 – Bipolar system with two 12-pulse units in series per pole

TR 60919-1 Amend. 1  IEC:2013(E) – 5 –

Figure 11 – Bipolar system with two 12-pulse units in parallel per pole

Replace Figure 11 by the following new figure:

1 1
1 1
1 1
1 1
IEC  809/13
Key
1 DC reactor
Figure 11 – Bipolar system with two 12-pulse units in parallel per pole

– 6 – TR 60919-1 Amend. 1  IEC:2013(E)

10.2.2 Electrical parameters
Replace, in item 1) the words “100 Hz” by “two times of the fundamental frequency”.

Replace, in item 3) the words “100 kHz” by “two times of the fundamental frequency”.

11.1 General
Add, in the second paragraph after the second sentence ending “…. during the acceptance

period of an HVDC system.” the following new sentence:

Please refer to Annex A for more information on factors affecting reliability and availability of
converter stations.
13.6 Optical fibre telecommunication
Add the following new sentence at the end of the third paragraph:
Use of OPGW (optical ground wire) as one of shielding wire is another typical arrangement
used in many overhead lines schemes.
18.1 General
Replace the third paragraph by the following new paragraph:
Field experience shows that thyristor valves generate about 10 dB to 15 dB less conducted
noise interference than mercury arc valves.
18.2 Performance specification
Replace the fifth paragraph by the following new paragraph:
Where dBm is defined as a means of interference measurement in which 0 dB is specified to
1,0 mW, which corresponds to 0,775 V pole-to-pole interference voltage assuming a line to-
line surge impedance of 600 Ω. In a 50 Ω cable on the low voltage side, 0 dBm and 1 mW
corresponds to 0,224 V.
Add the following new sentence at the end of the sixth paragraph after "…should be
evaluated":
It should be considered that the cost for a broad band PLC filter is significantly higher than

the cost for a narrow band PLC filter. Especially, filters for the lower frequencies
20 kHz to 50 kHz cost significantly more than PLC filters for higher frequencies.
Figure 23 – RY COM noise meter results averaged – Typical plot of converter noise
levels on the d.c. line corrected and normalized to 3 kHz bandwidth – 0 dBm = 0,775 V
Replace the existing title of Figure 23 by the following new title:
Figure 23 – RY COM noise meter results averaged – Typical plot of converter noise
levels on the d.c. line corrected and normalized to 3 kHz bandwidth – 0 dBm = 1 mW
corresponding to 0,775 V at a pole-to-pole surge impedance of 600 Ω

TR 60919-1 Amend. 1  IEC:2013(E) – 7 –

19 Radio interference
Replace the title and text of Clause 19 by the following:

19 Radio frequency interference

19.1 General
Historically Radio Frequency Interference (RFI) from high voltage electric power installations

has been related to interference with AM broadcast distribution due to high voltage a.c. line
corona. Consequently, this aspect is covered well in the literature and in relevant standards,
i.e. the CISPR 18 series. RFI from substations has been of minor practical concern. Therefore
very little has been documented regarding RFI from HV and MV substations. However, CIGRÉ
Technical Brochure No. 391, provides a thorough analysis of the aspect related to RFI from
substations, including HVDC substations. The analysis is based on both theory and
measurement results.
One important aspect that is treated in the Technical Brochure (TB) is the attenuation of the
RFI versus distance, including how the attenuation depends on the frequency.
RFI relates to a quite wide frequency range. According to CISPR 11 frequencies between
9 kHz and 400 GHz may be used for wireless communication and are therefore covered by
the International Telecommunication Union (ITU) current international table of frequency
allocations. Consequently, electromagnetic interference in this frequency range is defined as
Radio Frequency Interference (RFI). However, the frequencies below 150 kHz are nowadays
sparsely used and the standards for frequencies above 1 GHz are under development.
19.2 RFI from HVDC systems
19.2.1 RFI sources
RFI energy at the HVDC substation is produced by the turn-on and turn-off sequences in the
valves, from corona on the high voltage switchgear and lines, and from sparking and gap
discharge activities within the switchyard.
The RFI noise from the valve operation is predominantly produced by the fast voltage collapse
during the turn-on sequence. These transients excite localized resonance circuits formed by
stray capacitance and inductive elements in the bus structures, bushings, reactors, converter
transformers, etc.
RFI generated by the a.c. corona in the high voltage a.c. switchyard of the HVDC substation

varies significantly with the weather conditions and is highest at bad weather. RFI generated
by d.c. corona is highest near the positive conductor and decreases with the radial distance
from the conductor. DC corona does not vary very much with the weather conditions and is
somewhat higher at fair weather.
Recent measurements have indicated that there may be a significant high frequency RFI from
the a.c. part of a substation, especially at dry weather conditions if the substation is old. This
high frequency RFI noise is considered to be generated by gap discharge and/or sparking
activities. For more information reference is made to CIGRÉ TB No. 391.
19.2.2 RFI propagation
RFI generated in the HVDC substations may propagate as:
a) a guided wave transmission propagating along the HVDC transmission line;
b) a guided wave transmission propagating along the a.c. transmission lines;

– 8 – TR 60919-1 Amend. 1  IEC:2013(E)

c) direct wave radiation from the HVDC substation.

The attenuation of the RFI versus distance varies with the frequency as follows.

a) The attenuation for the line-to-earth mode of RFI propagating along the lines is in the
0,8
order of 3f dB/km with f in MHz. The attenuation varies with line design parameters and

the soil resistivity.
b) The attenuation for the line-to-line mode of RFI propagating along the lines is in the order
0,8
of 0,3f dB/km with f in MHz. The attenuation varies with line design parameters and the
soil resistivity.
c) The physics for attenuation of the direct wave RFI with distance is quite complex. As an

approximation, at a distance from a substation shorter than λ/2π or longer at a certain
distance d(SA) the attenuation of the field strength decreases as 1/r (where λ is the
wavelength of the EM radiation and r is the distance to the installation). For intermediate
distances, the attenuation is proportional to 1/r. The distance d(SA) depends on the
frequency, the height of the antennas and the soil properties. For more information
reference is made to CIGRÉ TB No 391. For a realistic example in the TB, the distance
d(SA) is in the order of 25 m at 50 MHz and increases linearly with the frequency for
higher frequencies. For lower frequencies than 50 MHz, the distance d(SA) varies as 1/f.
The implication of the above is that for RFI propagating along the lines, the high frequency
RFI vanishes after a few kilometres, especially the line-to-earth component that is dominating.
However, low frequency RFI will propagate quite a long distance, especially the line-to-line
component.
Within a few hundred meters from the substation, the direct wave RFI can have a quite broad
frequency range. However, when normal design is applied, the RFI has diminished to the
background RFI level after 0,5 km to 1 km.
19.2.3 RFI characteristics
The general characteristic of the RFI noise from an HVDC substation is repeated transients
regardless that the noise is produced by the commutation process, corona, sparking or gap
discharge. Due to the different sources the frequency characteristics of the broad band RFI
from a converter station can be quite complex and very irregular. To some extent this is valid
for any high voltage substation.
RFI noise generated by the commutation process of the HVDC converter has the following
characteristics.
a) Interference energy is directly proportional to the magnitude of the voltage jumps
produced during the turn-on sequences of the valves and also depends on circuit
parameters. The voltage jumps at turn-off has less impact as the rise time at turn-on is

much shorter than the rise time at turn-off.
b) As the RFI due to the converter commutation process depends on the circuit resonances,
the frequency spectrum is quite irregular.
c) Due to the defined rise time for the voltage jumps at turn-on, the RFI due to the
commutation process decays for frequencies above 1 MHz and is negligible for
frequencies above 10 MHz.
d) The noise
...