Vector Control of Permanent Magnet Synchronous Machine with Reduced Switch Five-Level Voltage Source Inverter

This paper presents a six switch five-level (0, ±Vdc/2, ±Vdc) VSI (voltage source inverter) fed PMSM (permanent magnet synchronous motor) drive. The circuit topology and number of switching devices are same as that of basic three phase two-level voltage source inverter. The implementation of reduced switch 5-level inverter improves the pulsating torque and dynamic speed response under various operating conditions. The concept of vector control is applied to obtain good dynamic performance and the machine can also be control like separately excited DC motor. Three PI controllers is employed as speed, torque, and flux controller and PWM technique is used to trigger switches of six switch 5-level inverter. The circuit configuration and PMSM model are developed in MATLAB/SIMULINK environment and the performance is investigated with change in speed and load torque. Based upon simulation result the performance of proposed technique is recommended for significant reduction in THD (total harmonics distortion) of stator current and ripple in electromagnetic torque without increased in additional cost of overall system.