Research on improved buck three-phase harmonic injection rectifier

Since the traditional buck power factor correction (PFC) circuit has little voltage stress requirements for the post-stage tube, the buck three-phase harmonic injection rectifier circuit is studied. Aiming at the phase-to-phase short circuit problem in the practical application of buck three-phase harmonic injection rectifier and the slow dynamic response of the circuit under the traditional double-closed-loop control strategy, the topology and control strategy of buck three-phase harmonic injection rectifier are improved. First, three sets of diodes are used in the topology instead of one set of diodes in the harmonic injection network. Secondly, the combination of feedforward signal and negative feedback signal in the traditional double closed-loop control strategy is changed from addition to multiplication. In order to verify the correctness of the improved circuit topology and control strategy, this paper analyzes the topology and working principle of buck three-phase harmonic injection rectifier circuit, describes the specific scheme and advantages of the improvement, and builds a simulation model for verification. The simulation results show the feasibility of improving the circuit, which can achieve unit power factor operation, reduce three-phase current harmonics, and improve system dynamic performance.