基于母线功率前馈的配网PET电压均衡控制

Voltage Equalization Control of PET in Distribution Network Based on Bus Power Feedforward

针对配网级联型电力电子变压器(PET)提出了一种基于低压直流母线功率前馈的电压和功率均衡控制策略。该控制策略将PET低压直流母线的能量需求前馈至输入级,指导输入级实现各级模块的功率均衡控制,同时利用隔离级来稳定各模块的直流电压,并采用相同的稳压指令实现各级直流电压的均衡控制。所提控制策略不仅能够有效解决因各级模块参数不匹配所导致的电压与功率不均衡问题,同时减少了目前PET控制环节,降低了各模块间的电量耦合关系。仿真和实验验证了所提控制策略的有效性。

A voltage and power equalized control strategy based on low-voltage DC bus power feedforward is proposed for cascade power electronic transformer(PET).The control strategy feedforward the energy demand of the PET low voltage DC bus to the input stage,guide the input stage to achieve power balance control of all modules,and use the isolation stage to stabilize the DC voltage of each module,and use the same voltage regulator to achieve the balanced control of DC voltage at all levels.The control strategy is proposed can not only effectively solve the problem of voltage and power imbalance caused by the parameter mismatch at all levels of modules,but also reduce the current PET control link and reduce the power coupling relationship between modules.Simulation and experiment verify the effectiveness of the proposed control strategy.