Robust Stabilization of Current Regulator for High-Speed IPMSM Drive Systems by Equivalent Resistance Gain

Abstract

In this paper, the stability of a current regulator for high-speed interior permanent magnet synchronous motor (IPMSM) drives under the motor parameter mismatch condition is analyzed. As a result, a fundamental decoupling control between d-axis and q-axis causes instability when the natural angular frequency of a current regulator is low under the motor parameter mismatch. The conventional method requires a low-pass filter that has an electrical time constant in order to achieve compensation for the d-q axis coupling components. However, it is difficult to implement the filter because the carrier frequency is limited by the total efficiency of the motor drive systems. Therefore, this paper also proposes a stabilization method for the current regulator based on an equivalent resistance gain in order to overcome this instability. One of the features in this paper is no use of the filter. In addition, the proposed method reduces the current overshoot by 1.1p.u. compared with the fundamental decoupling control.