连接弱同步支撑系统的电压源换流器优化矢量控制策略  

Optimized Vector Control Strategy of Voltage Source Converter Linked to Weakly-synchronized Support Systems

作　　者：罗晨曦 徐政[1] 陆韶琦 LUO Chenxi;XU Zheng;LU Shaoqi(College of Electrical Engineering,Zhejiang University,Hangzhou 310027,China)

机构地区：[1]浙江大学电气工程学院,浙江省杭州市310027

出　　处：《电力系统自动化》2018年第23期14-19,共6页Automation of Electric Power Systems

摘　　要：为克服采用矢量控制策略的换流器在接入弱同步支撑系统中失稳的问题,优化了电压源换流器的矢量控制策略。首先根据简化模型指出矢量控制的换流器由正负反馈两部分组成,向弱同步支撑系统供电时失稳是由于正反馈起了主导作用。其次为加强负反馈的作用,将系统频率偏差作为附加控制环节引入矢量控制器中,使改进后的控制策略能够应对弱同步支撑系统,甚至无源系统。最后仿真结果表明,这种优化控制策略在电压源换流站连于弱电网时的动态响应与虚拟同步机类似,并且在供电网络失去电源时无须切换控制策略。In order to overcome the instability problem of the converter in the weakly-synchronized support system with the vector control strategy,the vector control strategy of the voltage source converter is optimized.Firstly,according to the simplified model,it is pointed out that the vector control converter is composed of both positive and negative feedbacks.The instability of the converter in the weakly-synchronized support system lies in the leading role of positive feedback.Secondly,in order to strengthen the effect of the negative feedback,the frequency deviation of the system is introduced into the vector controller as an additional control,so that the improved control strategy can deal with the weakly-synchronized support system or even the passive system.Finally,the simulation results show that the dynamic response of the optimal control strategy is similar to the virtual synchronous machine when the voltage source converter is connected to the weak power grid.The control strategy is also able to supply passive network without switch between control modes.

关 键 词：矢量控制 附加控制 弱同步支撑系统 系统稳定性 电压源换流器 

分 类 号：TM46[电气工程—电器]