A Zero-Crossing Oscillation Elimination Method for Real-time Simulation of Brushless DC Motor

The FPGA-based real-time simulation of brushless DC motors (BLDCM) can achieve a good balance between the simulation speed and accuracy by using paralleled computing. However, the network decoupling method commonly used in the traditional BLDCM and its driver modeling will introduce the problem of zero-crossing oscillation in the blocking state. To address this problem, in this paper, an equivalent network decoupling method of motor and inverter is proposed along with a switch status identification algorithm, which constitutes a paralleled computing structure while eliminating the zero-crossing oscillation of the phase current. An ultra-low time-step of 100 ns is realized for the stable real-time simulation of BLDCM on FPGA. The model is verified by comparing simulation results with the Simulink SPS commercial library, which further stands out the advantages in the numerical stability of the proposed model. Finally, the effectiveness and application values of the proposed method are validated by an experimental prototype of the BLDCM driving system.