Series-Connected Hybrid Cascaded H-Bridge Voltage Disturbance Generator

A novel main circuit topology of voltage quality disturbance generator is proposed in this paper, mainly consisted by low-frequency cascaded H-bridge and high-frequency H-bridge modules. The topology is a hybrid structure, the mainly fundamental power of voltage quality disturbance generator is supplied by the system source and the small part of fundamental power is supplied by the inverter. The low frequency cascaded H-bridge inverter output fundamental waveform and voltage fluctuation and flicker waveforms, while the high-frequency H-bridge inverter output harmonic voltage waveforms, then the decoupled control of voltage disturbance is achieved in order to make sure the good dynamic and static performance. The low-frequency cascaded H-bridge is controlled by carrier phase shift and the high-frequency H-bridge is controlled by high-frequency SPWM with FPGA.