含VSC-HVDC的交直流混合系统潮流统一迭代求解算法

介绍基于电压源换流器(VSC)的新一代高压直流输电(VSC-HVDC)技术,具有可向无源网络供电、不会出现换相失败等众多优点。分析VSC-HVDC输电系统的原理及其中VSC的控制方式。针对不同控制方式下的VSC,分别推导其交流母线及直流系统相应的潮流修正方程式。提出VSC-HVDC交直流混合系统潮流的统一迭代求解算法,并以修改后的WSCC-9节点交直流混合系统的潮流计算为例,验证统一迭代求解算法的有效性。通过该潮流算法分析VSC-HVDC输电系统的稳态特性和有功功率损耗特性。

Uniform iterative power flow algorithm for systems equipped with VSC-HVDCs

VSC-HVDCs, based on voltage source converters(VSC), are the new generation of high voltage direct current(HVDC) transmission technology. This technology has attracted more and more attention for its favorable benefits such as no risk of commutation failures and possibility to feed to a weak ac system or even passive loads. The operation principle of VSC-HVDC and control modes of VSC were analyzed firstly. Considering different control modes of VSC,correction equations were deduced for VSC's ac buses and VSC-HVDCs respectively. On the basis of these correction equations, a uniform iterative power flow calculation algorithm for systems equipped with VSC-HVDCs was proposed. The validity of this algorithm was verified by power flow calculation for the modified WSCC-9-nodes ac and dc hybrid system. At the end, the steady-state characteristic and power loss characteristic of VSC-HVDCs were analyzed by use of this algorithm.