H桥级联多电平变流器的直流母线电压平衡控制策略  

Control Strategy for DC Bus Voltage Balance in Cascaded H-bridge Multilevel Converters

作　　者：王志冰[1] 于坤山[2] 周孝信[2] 

机构地区：[1]上海交通大学电子信息与电气工程学院,上海市闵行区200240 [2]中国电力科学研究院,北京市海淀区100192

出　　处：《中国电机工程学报》2012年第6期56-63,共8页Proceedings of the CSEE

基　　金：国家863高技术基金项目(2009AA05Z213)~~

摘　　要：H桥级联多电平变流器是一个非线性、多变量、强耦合系统,其中单个功率模块的直流母线电压平衡问题严重影响该类型装置的输出性能,并限制其应用范围。对变流器与系统之间的功率交换模型进行详细的数学推导,得出可以通过控制变流器负序电流、零序电压或负序电压的方式达到控制单相直流电压平衡的控制规律。结合全局平均直流电压控制策略和单模块直流电压控制策略,提出基于正负序电流分离解耦控制的通用三级直流母线电压控制方法,解决了H桥级联多电平变流器的直流母线电压平衡问题,并提高了装置的输出性能。仿真和实验验证了所提直流电压控制策略的有效性和可行性。The converter based on cascaded H-bridge multilevel topology is a nonlinear multiple variable and strong coupling system,in which the DC bus voltage balancing problem of single power module affects the output performance of similar equipment seriously,moreover restricts its applications.This paper analyzed the power exchanging relationship between converters and power systems in detail,and obtained a control law,which can balance the single phase dc bus voltage by controlling negative sequence currents,or zero sequence voltages,or negative sequence voltages of the converter.Combining the global average DC voltage control and the single module DC voltage control,the paper presented a universal three-step decoupling control strategy,which based on the separated positive and negative sequence currents,and which can solve the DC bus voltage balancing problem of cascaded H-bridge multilevel converters.In addition,it can improve the output capability of converters.The validity and feasibility of special DC bus voltage control strategy is verified by simulation results and experimental results.

关 键 词：H桥级联多电平变流器 静止同步补偿器 三相三线制系统 正负序电流分离 直流电压平衡控制 

分 类 号：TM46[电气工程—电器]