Robust Scalar Control of Synchronous Reluctance Motor With Optimal Efficiency by MTPA Control

Abstract

In order to achieve improved performance and efficiency of domestic and industrial fan/pump applications using low-cost solutions, the synchronous reluctance motors (SynRMs) remains a better choice than induction motors (IMs) which are still widely used for such applications despite its low efficiency during low speed operation. However, due to the lack of self-start capability the SynRMs need external drive and speed control algorithm to properly operate, which increases the production cost. For the purpose of providing low cost solutions for the SynRMs speed control, this paper presents a stable, reliable and robust scalar control for SynRMs. This control strategy implements the maximum torque per ampere loop for high efficiency operation and online parameter estimation for robust performance. The proposed solution presented in this paper can be implemented using a low cost MCU in PWM inverter with lower carrier frequency, thereby making the low cost SynRM drive for fan/pump application feasible and practical.

Keywords

• Synchronous reluctance motor
• scalar control
• SynRM
• MTPA
• V/F control
• online inductance estimation