Stability of matrix converter-fed permanent magnet brushless motor drive systems

This paper analyses the stability of matrix converter-fed permanent magnet brushless AC motor drive systems. By employing state-space averaging technique, the governing equations for the dynamics of the drive system are derived. The stability of the system is analyzed by computing the eigenvalues of the Jacobian matrix of the linearized state-space equation under a given operating condition. It is shown that if the voltage transfer relation of a matrix converter is not ideal, the stability boundary of the converter-fed drive system will be influenced by its current/speed control loop bandwidth, and modulation strategies as well as the direction of the power flow (motoring or regeneration). The analytical prediction is validated by extensive time domain simulations. The findings of the paper provide an important understanding of how the drive control should be designed to maximize the stability margin for four quadrant operations.