A Simple Harmonic Reduction Method in Multipulse Rectifier Using Passive Devices

This paper proposes a novel and passive harmonic reduction method at dc link of multipulse rectifier (MPR). The proposed method uses a single-phase diode-bridge rectifier to generate circulating current, which can shape the input line current of MPR. The input side of the single-phase diode-bridge rectifier is connected with the secondary winding of interphase reactor (IPR), and its output side is connected with load, which can recycle the harmonic energy and feed to load. The operation mode of the single-phase diode-bridge rectifier is analyzed, and the turn ratio of the IPR is designed optimally. Under ideal condition, the proposed MPR operates as a 24-pulse rectifier, and its total harmonic distortion (THD) of input line current is about 7.6%. Most of all, the proposed method is easy to be used in different 12-pulse rectifier topologies, and its conduction losses are far less than that of the conventional double-tapped IPR. Simulation and experiment results show that the THD of input line current is less than 5%.