Optimum Design of 48-Pulse Rectifier Using Unconventional Interphase Reactor

In order to simultaneously reduce the harmonics of input line current and ripple of load voltage in multipulse rectifier, this paper proposes a 48-pulse rectifier using the unconventional interphase reactor (IPR) with an auxiliary single-phase diode-bridge rectifier at the dc link. The primary winding of the unconventional IPR is triple-tapped, and the secondary winding is connected with a single-phase diode-bridge rectifier. The operation mode of the unconventional IPR is analyzed, and the optimal tap ratio and turn ratio are designed. With the optimal parameters of the IPR and the optimal conduction time sequence of power devices, the proposed rectifier extends the conventional 36-pulse rectifier operation to a 48-pulse operation and draws near sinusoidal input line currents, the total harmonic distortion (THD) of which is about 3.81%. The proposed 48-pulse rectifier is easy and simple to implement, and it is more suitable for high-voltage and large-current application. Some simulation and experiments are provided to validate the theoretical analysis.