TY - JOUR
T1 - Control strategies for HVDC transmission system with parallel connection of converters
AU - Li, Shaohua
AU - Wang, Xiuli
AU - Zhang, Ailing
AU - Peng, Zhong
AU - Jing, Xueji
N1 - Publisher Copyright:
© 2015 Automation of Electric Power Systems Press.
PY - 2015/11/10
Y1 - 2015/11/10
N2 - With the development of high voltage direct current (HVDC) transmission technology in China, parallel converters are drawing ever-increasing attention to their structure. The HVDC transmission system with parallelly connected converters is particularly advantageous when the transmission is built by stages or in the de-icing operation mode. The characteristics of a 4-terminal HVDC system with parallel converters are analyzed at length. A new multi-terminal dc system coordinated mode is proposed for rectifier control of DC current and inverter control of DC voltage. And an additional special DC balancing control function is applied to avoid an unambiguous operating DC voltage. This coordinated mode has not only retained the relative independence of the bi-parallelly connected DC system as best it can, but also it has simplified the control system design for the 4-terminal HVDC transmission. In addition, it is now possible to realize flexible power allotment between parallelly connected converters. De-blocking the second valve and blocking the first valve being of special interest for parallel operation, methods of doing this are also described. Finally, a case study of 4-terminal HVDC system with parallelly connected converters has validated the control strategies using PSCAD/EMTDC.
AB - With the development of high voltage direct current (HVDC) transmission technology in China, parallel converters are drawing ever-increasing attention to their structure. The HVDC transmission system with parallelly connected converters is particularly advantageous when the transmission is built by stages or in the de-icing operation mode. The characteristics of a 4-terminal HVDC system with parallel converters are analyzed at length. A new multi-terminal dc system coordinated mode is proposed for rectifier control of DC current and inverter control of DC voltage. And an additional special DC balancing control function is applied to avoid an unambiguous operating DC voltage. This coordinated mode has not only retained the relative independence of the bi-parallelly connected DC system as best it can, but also it has simplified the control system design for the 4-terminal HVDC transmission. In addition, it is now possible to realize flexible power allotment between parallelly connected converters. De-blocking the second valve and blocking the first valve being of special interest for parallel operation, methods of doing this are also described. Finally, a case study of 4-terminal HVDC system with parallelly connected converters has validated the control strategies using PSCAD/EMTDC.
KW - Converter de-blocking/blocking control
KW - DC current balancing control
KW - Dual principle
KW - High voltage direct current (HVDC)
KW - Parallelly connected converters
UR - https://www.scopus.com/pages/publications/84948782727
U2 - 10.7500/AEPS20150105001
DO - 10.7500/AEPS20150105001
M3 - 文章
AN - SCOPUS:84948782727
SN - 1000-1026
VL - 39
SP - 132
EP - 137
JO - Dianli Xitong Zidonghua/Automation of Electric Power Systems
JF - Dianli Xitong Zidonghua/Automation of Electric Power Systems
IS - 21
ER -