A Dead-Time Compensation Strategy Based on an Online Learned Artificial Neural Network

This article presents an innovative approach to mitigate the harmonic distortion of the phase currents of a permanent magnet synchronous motor (PMSM) controlled by a field-oriented control (FOC) algorithm. The issue of phase current harmonic distortion is often a consequence of the output voltage deformation caused by the nonlinearities of the voltage source inverter (VSI). The relationship between the disturbance voltages of the inverter and the phase currents of the motor is nonlinear. Therefore, we used an artificial neural network (ANN) to identify the compensation voltages. The topology is designed to allow the neural network to solve complex problems with the limited computing resources available on the AURIX TC397 microcontroller. The input vector is assembled from quantities available in the PMSM FOC algorithm. The online learning process based on the backpropagation algorithm is adapted to operate directly on the microcontroller. The proposed strategy with ANN is verified on a real PMSM. The results show the excellent ability of the proposed ANN to suppress the harmonic distortion of the PMSM phase currents without knowledge of the VSI parameters.