Study on Reduced Cost of Non-Salient Machine System Using MTPA Angle Pre-Compensation Method Based on EEMF Sensorless Control

Abstract

When a consumer chooses a product, one of the most important considerations is price. Therefore, cost reduction is the most important factor when manufacturing a product. This paper has applied the sensorless method to remove the position sensor in an interior permanent magnet synchronous motor (IPMSM) system and examined the way to reduce the use of the trigonometric function in order to lower the dependency on a high-end CPU. A sensorless method has been studied to use an extended electromotive force (EEMF) that can increase the degree of freedom of the motor in the IPMSM system. In addition, an observer is applied to the estimated position to stabilize the system. Furthermore, many trigonometric functions are used for driving the IPMSM. Since this trigonometric function requires decimal point operations, that requires a lot of computation time and a high-performance CPU. Therefore, this paper proposes a new method to pre-compensate the maximum torque per ampere (MTPA) angle as a way to reduce the use of the trigonometric functions which makes a high-spec CPU unnecessary. Simulations and experiments are conducted to verify the proposed control algorithm.

Keywords

• maximum torque per ampere (MTPA)
• current angle pre-compensation
• extended electromotive force (EEMF)
• sensorless control
• motor drive topology