基于无谐波检测和选择性谐波补偿原理的组合式同相供电系统控制策略

Control strategy for combined co-phase power supply system based on theory of control without harmonic detection and selective harmonic compensation

针对组合式同相供电系统同相补偿装置(CCD)的常规控制方法受负载电流检测精度影响严重,且不能良好跟踪高速铁路负载高次谐波电流的缺陷,提出一种选择性谐波电流控制策略。该控制策略仅需要保留CCD的两单相变流器输出电压、电流的检测部分,不需要检测负载电流;并通过矢量比例积分控制器对连接负载的单相变流器输出电流误差中的各次谐波单独跟踪。该设计方法不受负载电流检测精度的影响,对牵引负荷各个频段谐波都具有良好的跟踪性能。利用MATLAB/Simulink搭建组合式同相供电的常规控制模型、改进控制模型和基于改进控制策略的半桥四臂模块化多电平电路模型,对交-直型、交-直-交型、混跑3种负载分别进行控制,仿真验证了改进电流控制方法的正确性以及在实际工程实现中的有效性。

The conventional control method is seriously influenced by load current detection accuracy and can＇t well track high-order harmonic current of high-speed traction loads,a selective harmonic current control strategy for CCD（Co-phase Compensation Device） in combined co-phase power supply system is proposed.This control strategy needs to detect only the output voltage and current of two single-phase converters but not the load current. The VPI（Vector Proportional Integral） controller is applied to independently track each harmonic current in the output current error of single-phase converter connected with load. The proposed method is not affected by the impact of load current detection accuracy,and has good performance of tracking each harmonic current of the traction loads. The conventional and modified models of combined cophase power supply system,and the model of HB-MMC4 based on proposed control strategy are established based on MATLAB/Simulink. Simulative results for AC-DC,AC-DC-AC and mixed running loads respectively verify the correctness of the proposed current control method and the effectiveness of its application in practical project.