Development of FW and MTPV Control for SynRM via Feedforward Voltage Angle Control

In order to develop a wide speed range operation of synchronous reluctance motor (SynRM) drive system for constant torque, constant power and reduced power regions, an extended speed control (ESC) with maximum efficiency (ME), flux weakening (FW), and maximum torque per voltage (MTPV) is proposed in this study. Firstly, a conventional FW control system with field-oriented control is introduced. Moreover, to achieve the ME operation, a lookup table of the results of ME analysis by using the finite element analysis technology is adopted to produce the d-axis current commands for the current control mode of the SynRM in the constant torque region. Furthermore, the FW voltage controller is employed to produce the incremental value of the stator voltage command to achieve the maximum voltage limit. In addition, a novel feedforward based voltage angle controller with an MTPV limiter is designed to generate the voltage angle command for the voltage control mode in the constant power and reduced power regions. Finally, the proposed ESC system is implemented in a 32-bit floating-point digital signal processor TMS320F28075 and its robustness and effectiveness are verified by some experimental results.