Performance for position control of two permanent magnet synchronous motors with the five-leg inverter

Recently, The five-leg inverter, with which we are able to control two AC motors independently, is suggested [1]-[6]. This inverter has five legs, so we make space for one leg compared with using two three-leg inverters. In this paper, the method of independent vector control of driving two permanent magnet synchronous motors (PMSMs) is described. Although it is difficult to drive two PMSMs in parallel with a single three-leg inverter, that is achieved by using the five-leg inverter. However, the five-leg inverter has two failings. Applying the proposed method, voltage utility factor (VUF) is 50%, and the amplitude of the peak current flowed common leg is twice as others. In order to improve the second problem, this paper presents that the method of reducing loss at the common leg under the driving in parallel.