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.