Improved direct torque control for interior permanent magnet synchronous motor with constant switching frequency

Abstract

Industrial use of alternating current (AC) motors have been prevalent in the last century where they have been found in many devices and systems which help improve the way of human life. Over the years, several methods have been established in providing control for these AC motors such as the synchronous AC motor. Each of these control methods have been discussed greatly by others and they will be discussed again in this final year project report where particular emphasis will be placed especially on the application of the Direct Torque Control (DTC) method on Interior Permanent Magnet Synchronous Motors (IPMSM). The bulk of this final year project report will cover the design and development of an improved DTC control method which will surpass the performance of the classical DTC control method which has been used by others in the past decade. Major improvements such as reduced torque and current ripples are expected to be achieved by this new and improved DTC control scheme which leads to benefits such as accurate torque control, dynamic speed accuracy as well as lesser current losses. In addition to these advantages, the improved DTC control scheme also retains the characteristic of fast torque response which is a common trait of the classical DTC control scheme. Emphasis will also be placed on the hardware construction and software development needed to achieve this improved DTC control scheme where observations and recommendations will also be suggested based on the real time experiments conducted on the IPSM using the improved DTC control scheme.