海上风电接入多端柔性直流输电系统中换流站退出运行时直流功率再分配策略

Optimized power redistribution of offshore wind farms integrated VSC-MTDC transmissions after onshore converter outage

大容量海上风电场通过多端柔性直流输电系统接入主网是未来极具前景的并网方式。文章研究了岸上换流站故障退出运行后VSC-MTDC系统直流功率的优化再分配策略。以减小潮流重分配对交流电网频率稳定影响为优化目标,合理地重新配置各受端换流站的控制器,使转移功率完全被故障端换流站所在交流电网消纳;在PSCAD/EMTDC中搭建改造的39节点系统,所设计的直流功率再分配策略对系统频率稳定提升得到了验证。

Voltage source converter based multi-terminal HVDC （VSC-MTDC） transmission is prospective to integrate gigawatt offshore wind energy. This paper presents an optimized power redistribution method in VSC- MTDC system after onshore converter outage. The transferred power is redistributed among the healthy onshore converters within the disturbed ACsystem with the optimized objective of better frequency performance. The outer controllers of the onshore converters are reset according to the new DC power flow calculation. Simulation verifications are carried out in a modified New England 39- bus system in PSCAD/EMTDC.