考虑定功率-定关断角方式的交直流协调三级电压控制方法

Tertiary Voltage Control Method for AC/DC Coordination Considering Constant Power-Constant Extinction Angle Mode

在送-受端定功率-定关断角(CP-CEA)的直流控制方式下,两侧换流站调压控制的相互耦合会导致交直流系统自动电压控制(AVC)不协调情况下的额外动作问题更突出。为此,文中提出了考虑CP-CEA方式的交直流协调三级电压控制方法。在常规交流系统三级电压控制模型的基础上,新模型增加了直流线路有功损耗目标、送-受端换流关口无功的控制死区约束以及直流电压和触发角的安全运行约束,从而实现了受端交流系统三级电压控制对直流系统的协调作用。以IEEE 39节点修正系统和实际河南电网为例,仿真验证了所建模型的有效性。仿真结果表明,所提方法不仅可以避免因交流系统潮流波动引起的换流站离散调压设备动作,而且能有效降低交直流系统有功损耗。

Under the DC control mode of constant power-constant extinction angle(CP-CEA)at the sending-receiving end,the mutual coupling of voltage regulation control of converter stations on both sides will lead to more prominent additional action problems in the case of the incoordination of automatic voltage control(AVC)for AC/DC systems.Therefore,a tertiary voltage control method for AC/DC coordination considering CP-CEA mode is proposed.Based on the tertiary voltage control model of the conventional AC system,the active power loss target of the DC line,the control dead-time constraints of the reactive power at the sending-receiving end of the converter port,and the safe operation constraints of the DC voltage and the triggering angle are added into the new model,so as to realize the coordination effect of the tertiary voltage control of the receiving-end AC system on the DC system.Taking the IEEE 39-bus correction system and the actual Henan power grid of China as examples,the validity of the built model is verified by simulation.The simulation results show that the proposed method can not only avoid the action of discrete voltage regulation equipment in converter stations caused by power flow fluctuation of the AC system,but also effectively reduce the active power loss of AC/DC system.