Abstract: An electrically excited synchronous motor (EESM) can achieve the desired torque and angular velocity by precisely controlling the phase current. Compared to offline methods, machine learning-based online control methods have advantages such as real-time performance, high accuracy, and low model complexity. However, they face challenges related to a large number of parameters and difficulties in setting them. Therefore, this paper proposes an EESM control method based on the Bayesian optimization (BO) learning model. This method utilizes entropy search and expectation enhancement techniques in BO to automatically adjust the model parameters. Simulation analysis results demonstrate that the proposed method can achieve automatic adjustment of the learning model parameters, improve the accuracy of the learning model, and effectively reduce the number of repeated experiments. Furthermore, the comparison results indicate that when the training sample size is large, neural networks outperform Gaussian processes in terms of accuracy and time complexity, but they require more memory. On the other hand, when the training sample size is small, Gaussian processes exhibit higher accuracy, similar computational costs to neural networks, and lower memory usage.
Keywords: electrically excited synchronous motor (EESM); reference current; machine learning; Gaussian process regression (GPR); neural network; Bayesian optimization (BO)