Improved Optimal Control of Interior Permanent Magnet Synchronous Machine with Simplified Inverter Nonlinearity Compensation

This paper proposes a new voltage compensation method for the optimal control of interior permanent magnet machines (IPMs) especially at the field-weakening region considering the inverter nonlinearity. The way to experimentally generate the inverter voltage drop compensation is presented. In the model-based optimal control, the compensation voltage should be converted to dq frame, therefore becomes a multivariable function of current vector magnitude, dq angle, and electrical angle of rotor rotation, which complicates the solving process of optimal control problem. This paper proposes a compensation voltage which is a function of only current magnitude and also ensures that the optimal operation is always achieved. Simulation and experiment results are presented to validate the proposed method.