Theory and Simulation of the Dual Mode Inverter Control

An inverter topology and control scheme has been developed that can drive low-inductance, surfacemounted permanent magnet motors over the wide constant power speed range required in electric vehicle applications. This new controller is called the dual-mode inverter control (DMIC) [1]. The DMIC can drive both the Permanent Magnet Synchronous Machine (PMSM) with sinusoidal back emf, and the brushless dc machine (BDCM) with trapezoidal emf as a motor or generator. Simulation results show that by neglecting motor and inverter loss mechanisms, the constant power speed range of the DMIC is infinite. The simulation results are supported by closed form expressions for peak and rms motor current and average power derived from analytical solution to the lossless differential equations. The analytical solution shows that the range of motor inductance accommodated by the DMIC is more than an order of magnitude making the DMIC compatible with both lowand high-inductance BDCMs. Finally, classical hysteresis band current control, used for motor control below base speed, is integrated with the phase advance of DMIC applied above base speed. The power versus speed performance of the DMIC is then simulated across the entire speed range. * Prepared by Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725. The submitted manuscript has been authored by a contractor of the U.S. Government under contract DEAC05-00OR22725. Accordingly, the U.S. Government retains a nonexclusive, royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for U.S. Government purposes. The corresponding author of this paper is John W. McKeever, a Senior R&D Staff Member with the Oak Ridge National Laboratory. Mr. McKeever’s address is National Transportation Research Center, 2360 Cherahala Boulevard, Knoxville, Tennessee 37832; phone 865-9461316; fax 865-946-1262; and email [email protected]. This paper has not been presented at a conference.