Development of a Modular Controller to Minimize Current Ripple in Low Inductance Coreless Permanent Magnet Motor


In this paper, a development of a modular controller to minimize current ripple in a low inductance coreless permanent magnet synchronous motor (CPMSM) is described. Based on individual modules, the controller uses a 60 degree commutation scheme instead of the conventional 120 degree. The neutral point of the motor’s windings is connected to an intermediate voltage level provided by a capacitor bank relative to the DC power bus. This feature allows the utilization of a single current sensing point that is used to regulate the motor’s torque by hysteretic current level control. With this simplification of the control strategy it was possible to use a single Programable Logic Device (PLD) to implement all the processing in the controller. The controller was built and tested, and the results showed efficient and smooth operation of the motor.

Keywords: Current ripple, Permanent magnet motor, Low inductance

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