一种新型自均压二极管钳位级联有源滤波器

提出一种新型二极管钳位级联多电平拓扑,在半桥单元拓扑上增加钳位二极管,为直流电容提供单向钳位通路。在该拓扑中,只需对阀体两端单元的直流电压进行控制就可实现均压控制,且每相阀体只需2个直流电压传感器,结构简单。将拓扑拓展到三相结构,提出了二极管钳位多电平有源滤波器(APF)拓扑及其控制方法。搭建了7电平二极管钳位多电平APF仿真模型和实验样机。实验结果表明,该拓扑自均压控制和谐波补偿效果良好,控制算法简易、可行。

A Novel Voltage Self-balance Diode-clamped Cascaded Multilevel Active Power Filter

A novel diode-clamped cascaded multilevel converter topology is proposed.The half-bridge cascade cell is added a clamping diode to the DC-link capacitor,and it may provide an energy channel clamping in single direction for capacitor voltage.Via the clamping diodes,only the top and bottom cells of a phase arm need to be controlled to realize each cell’s capacitors voltage balance.Therefore,the DC-link voltage sensors of a phase arm are reduced to two,much less than that of traditional cascaded converter.A three-phase multilevel active power filter(APF) topology based on the proposed diode-clamped cascaded multilevel converter topology is provided,and its control strategy is presented as well.A simulation model and an experiment prototype of seven-level diode-clamped cascaded multilevel APF are built.The simulation and experiment results show that the novel cascaded multilevel converter topology has good performance in voltage self-balance control and harmonics compensation,and the control algorithm is easy and feasible.