特高压直流控制系统融冰工作方式研究

针对输电线路覆冰严重影响特高压直流输电可靠性的现状,讨论了特高压直流工程阀组单极2阀组并联和双极2阀组并联两种方案;提出了特高压直流系统融冰的控制策略——整流侧并联的2个阀组分别处于定电流控制,逆变侧并联的2个阀组一个定电流控制、另一个定电压控制,其中逆变侧定电流阀组的电流参考值跟踪线路电流测量值的一半,达到平均分配电流的目的,定电压状态的阀组控制整个极的直流电压;分析了融冰方式需要在原直流控制保护系统基础上增加的功能。针对单极2阀组并联的融冰方案进行的实时数字仿真(RTDS)试验证明该融冰方案是可行和有效的。

Research on De-icing Operation Mode of the Control and Protection System for UHVDC

Ice-coating of overhead transmission lines does harm to the reliability of Ultra High Voltage Direct Current (UHVDC). This paper discusses two kinds of de-icing scheme of parallel dual valve group for UHVDC: parallel operation of monopolar dual valve group and parallel operation of bipolar dual valve group. The de-icing control strategy for UHVDC system is presented,the parallel valve groups at rectifier side are both in current control,and at inverter side,one is in current control in which current reference is half of measurement of DC line current in order to balance of parallel valve groups,the other is in voltage control which control the voltage of them. The additional function for de-icing mode on the conventional UHVDC control and protection system is analyzed. Based on the de-icing scheme of parallel operation of monopolar dual valve group,the real-time digital simulation (RTDS) test is carried out. The feasibility and validity of this de-icing scheme is proved.