Development of a new approach for wide speed range of PMSM

Permanent Magnet Synchronous Motor (PMSM) with lower inductance values suffering from the narrow Constant Power Speed Range (CPSR). The traditional approaches for extending CPSR operation included adding an additional inductance or a thyristor controlled inductance in series with the motor. However, these approaches increase the cost, complexity, and derate the inverter of the drive system. In this paper, a new solution to increase the CPSR of the PMSM is introduced to avoid the drawbacks of traditional approaches. The idea is to select the inverter reference currents values to maintain Maximum Torque Per Ampere (MTPA) and to increase the output inductance seen by the inverter without adding any physical inductance or thyristor. This is achieved by adding a virtual inductance to the stator current equation. The value of the virtual inductance indicates how broaden is the speed range. The proposed system has the advantages of wide speed range operation, low size, low cost, and simple control. MATLAB simulations and complete hardware setup based on the Texas DSP (TMS320F28335) has been constructed to verify the new approach.