Direct Torque Control - A Solution for Mono Inverter-Dual Parallel PMSM System

The objective of this paper is to present a Direct Torque Control (DTC) algorithm for controlling system composed by two Permanent Magnet Synchronous Motors (PMSM) operating in parallel, fed by a single power inverter. In this system, it is expected that both motors will get the same speed even if they have different conditions of load torque. The principle of DTC algorithm is considered as follows: The space vector plane is divided into 12 sectors of 30 each of four input information are considered, two related to the flux of each machine and two related to the torque. Based on these 16 combinations in 12 different sectors, a switching table is proposed to determine the best vector of voltage to be applied by the inverter. Simulation results in Matlab/Simulink indicated that the algorithm (DTC) is well adapted for the synchronism of this system over a wide range of operations.