级联H桥APF的CPS-TPWM调制策略及应用初探

Study on the Application of Cascaded H Bridge APF Based on CPS-TPWM Modulation Strategy

电气化铁路牵引负荷的非线性、不对称和波动性所引起的谐波、三相不对称等,会显著影响牵引供电系统的供电质量,并联电容器组无源补偿或带有复杂降压变压器混合补偿的工程措施,其动态补偿性能较差,且系统构造复杂.基于此,提出将级联H桥多电平单相有源电力滤波器(APF)直接接入牵引供电网,并引入载波相移梯形波脉宽调制(CPS-TPWM)策略,实现系统的补偿控制.通过Matlab/Simulink环境下搭建的27个单元的单相级联H桥APF主电路和控制系统模型,仿真验证了补偿控制方案的可行性和有效性.

The harmonic,three-phase asymmetry,and other problems caused by the nonlinear,asymmetry,and fluctuation of the traction load of the electrified railway significantly affect the power supply quality of the traction power supply system,and the engineering scheme using the passive shunt capacitors or hybrid compensation with complex step-down transformers has poor dynamic compensation performance and complicated system construction.To solve the above problems and achieve compensation control of the system,the study proposed to connect the multi level single phase active power filter(APF)of cascaded H-bridge directly to the traction power supply network and to adopt the carrier phase shifted trapezoidal wave pulse width modulation(CPS-TPWM)strategy.By setting up 27 units single phase cascaded H-bridge APF main circuit and control system in Matlab/Simulink environment,the feasibility and effectiveness of the proposed control compensation scheme were verified by simulation.