基于扩展等面积法分析直流降功率速率对系统稳定性影响

摘要

High-voltage direct current transmission has a high transmission reliability, but when the high voltage grade ac lines connected to the inverter side out of service, we can choose non-blocking dc system, instead of using the low voltage grade lines which connected to the inverter side continue transmission power.However, this situation may cause inverter side to face the danger of overload, and meanwhile, it may reduce the stability of the system.In this paper, we adopted the way of dropping the DC operating power to avoid the possibility of happening the overload, and analyzed the mechanism of choosing the appropriate dc power reduction rate to increase the stability of the system which based on extended equal area method under fault condition.%高压直流输电具有较高的输电可靠性，但当逆变侧交流电网高电压等级交流场退出检修时，可选择不闭锁直流输电，继续通过低电压等级交流场向外输送电力。这就有可能造成逆变侧交流场出现过负荷情况，同时系统的稳定性降低。文中提出通过直流降功率来避免逆变侧交流电网过负荷，且基于扩展等面积法从机理上分析了在故障情况下选取适当的直流降功率速率增加了系统的稳定性。