摘要
直流系统的定有功控制方式牺牲了交流侧系统在发生事故时相互支援的能力。根据电压源型换流器高度可控、灵活高效的特点,提出一种适用于多端柔性直流输电(voltage sourced converter based multi-terminal high voltage direct current,VSC-MTDC)互联系统的频率稳定控制策略。该策略不需要站间通信,通过附加频率控制使换流站可对交流侧系统的频率做出响应,通过直流电压斜率控制使多个换流站共同分担直流网络中的不平衡功率,从而实现了一侧交流系统频率发生较大变化时,其余交流系统可通过VSC-MTDC进行功率支援,缓解事故系统的有功不平衡状况。最后通过仿真软件PSCAD/EMTDC进行仿真验证,结果表明所提策略充分利用了VSC-MTDC互联系统的频率调整能力,减小了故障端系统的频率变化量。
The constant active power control mode cannot offer mutual support for power occurs in the power grid at AC grids at AC side while accident side. Since the voltage sourced converter is highly controllable, flexible and efficient, a frequency stability control strategy suitable for interconnected voltage sourced converter based multi-terminal high voltage direct current （VSC-MTDC） system is proposed. Not needing communication between inverter stations, only using additional frequency control the inverter stations can respond to the frequency of power systems in AC side, and through controlling the droop of DC voltage multi inverter stations can jointly share the power unbalance in HVDC network, thus when the frequency in one of the AC systems evidently changes, the rest of AC systems can offer power support via VSC-MTDC system to mitigate the active power unbalance in the faulty AC system. The PSCAD/EMTDC based simulation results show that the proposed strategy; can fully utilize the frequency adjustment capability of interconnected VSC-MTDC system, and the frequency fluctuation extent in the faulty AC system is reduced.
出处
《电网技术》
EI
CSCD
北大核心
2014年第10期2729-2734,共6页
Power System Technology
基金
国家重点基础研究发展计划项目(973项目)(2013CB2280204)
国家电网公司科技项目(多端柔性直流系统分析与协调控制策略研究)~~
