Research on High Precision Speed Control Strategy Based on Three-phase Four-bridge Topology

This paper mainly focuses on the research of the AC servo system. With the development of the AC servo technology, the requirements for the speed range and accuracy of the system are getting higher and higher. Meanwhile, it also puts forward higher requirements on the electromagnetic compatibility characteristics of the system. In order to suppress the common mode voltage, propose a three-phase four-birdge inverter topology and an optimized SVPWM algorithm. Below the rated speed, use the virtual injection MTPA control algorithm to achieve constant torque control. While above the rated speed, use the field weakening control algorithm with current phase angle adjustment to achieve the speed increase of the field weakening. Finally, the accuracy of the algorithm is verified by building a simulation model. The algorithm can make the speed error of 120 kW motor stable speed less than 2 %.