Performance Analysis of a Five-leg Inverter for the Train Propulsion System

Abstract

This paper analyzes the performance of two three-leg inverters and a five-leg inverter and proposes the optimal operation conditions in applying the five-leg inverter for the train propulsion system. The five-leg inverter offers a saving of two switches compared with the standard two three-leg inverters and it is possible to control two three-phase motors independently by using a control board. All of these features lead to a potential reduction in capital cost and miniaturization of system. In this paper, first, the analysis of the existing motor control method and PWM method for two-traction motor drive of urban railway is implemented. Next, the operation principle and performance of five-leg inverter is introduced. Through the analysis, when it applies the same motor control method and the same PWM method for three-leg inverter and five-leg inverter, the characteristic of motor`s speed and torque is compared.