Compensation Technique for Delay Times of Various Feedback Filters in a Three-Phase Control System for Synchronous Machines

Field-oriented control of permanent magnet synchronous machines, used in high-precision control applications, suffers from significant problems due to the delay effect of the filter. To address these problems, this study focuses on the analysis, design, and realization of various analog and digital filters. Based on the analysis results, it is mathematically demonstrated that the output signal of the filter shows different delay times; moreover, the delay times and magnitudes for each filter are obtained. This paper also proposes a delay time compensation technique for various filters, focusing on filters used in the current feedback system of high-speed controls. The results were verified through simulations and experiments. The presented analysis and experimental results show that the delay time compensation technique proposed in this paper is effective for several types of filters used in the control systems of electrical machines. The proposed method in this paper facilitates the use of any type of filter in motor/generator control systems with the DT compensation.