Research on AC electronic load based on back to back single-phase PWM rectifiers

This paper presents a kind of AC electronic load for testing AC power source with energy recycling capability. The proposed structure is based on back to back single-phase PWM rectifiers of the voltage-source type. The operation principle of the model is described in detail to research the power matching problem and DC bus harmonic phenomenon. To achieve power balance and good performance, an independent control strategy for the two PWM rectifiers is proposed. In addition, a novel control technique of compensating second-harmonic voltage of dc bus is put forward. The research is proved to be effective in power recovery by the prototype experiments.