Direct torque control of PMSM using fuzzy logic with PWM

Since its development, permanent magnet synchronous machines (PMSM) has been used in a number of specific applications. However, in recent years PMSMs have become more attractive due to developments in new materials for permanent magnets and in semiconductor technology for converter design. Recent investigations have proposed some implementations applying the direct torque control (DTC) technique to PMSM motor drives, offering a fast and accurate control. This paper presents a modified DTC scheme, using fuzzy logic with pulse wide modulation (PWM) to improve stator flux and the electric torque by significantly reducing their ripple. The proposed method effectiveness has been verified by computer simulations and experimental tests on a laboratory prototype. These results are compared with the ones obtained with a modified DTC using a PI controlled PWM with current limit.