Discrete control technology for wind power grid-connected converters

A discrete-domain based grid-connected inverter control strategy is studied for the problems of poor dynamic performance and weak anti-interference of low switching frequency to digital controllers in the practical application of high-power LCL grid-connected inverters in the continuous domain. Firstly, a continuous-domain mathematical model of the LCL grid-connected inverter is established and controlled by a current-loop controller (PI) to realize active damping control of the grid-connected inverter, and a discrete model of the LCL grid-connected inverter is established by the direct design method and designed directly in the z-domain. Then the state-space design method with pole configuration is used to control the current using the method of complex space vector in the synchronous dq coordinate system The control strategy of the grid-connected inverter in the discrete domain is discussed based on the discrete domain mathematical model and the internal mode control principle; finally, the designed control algorithm is compared with MATLAB/Simulink simulation. The results show that designs in the discrete domain have better dynamic performance and are more resistant to disturbances than designs in the continuous domain.