Design and Parameter Tuning of Nonlinear Active Disturbance Rejection Controller for Permanent Magnet Direct Drive Wind Power Converter System

When the permanent magnet direct-drive wind power converter system is disturbed by the grid side and the motor side, the output voltage of the converter and the DC bus voltage will change suddenly, and the power quality of the grid will deteriorate. The nonlinear active disturbance rejection controller (NLADRC) is used in the grid-connected inverter control system. Because of its ability to estimate and compensate disturbances, it can effectively improve the system's anti-disturbance ability and tracking accuracy. However, NLADRC still has problems such as many parameters to be adjusted and unclear physical meaning. This article explores the influence of various parameters on the dynamic performance of the entire system, and summarizes the direction and law of parameter tuning. At the same time, the frequency domain analysis method is used to express the gain parameter in the expanded state observer in the form of bandwidth, which provides a basis for parameter adjustment in actual engineering. The control algorithm proposed in this article is applied to the 3MW permanent magnet direct-drive wind power experimental platform. The experimental results under various working conditions show that NLADRC can effectively improve the anti-interference performance of the grid-connected inverter.