Improvement on the grid connected control strategy of direct drive permanent magnet wind power system

摘要

In recent years, variable speed permanent frequency generation, as the main part of wind power generation, has been widely concerned by people. In this paper, choose direct-drive permanent magnet wind power system as the study system, based on the mathematical model of three-phase voltage type PWM inverter on the system grid, then make some improvements on the double-closed loop control strategy, in which grid voltage oriented is used commonly. In the outer voltage loop control, the parameters of PI regulator have been increased online using Fuzzy PI control, reduce the system overshoot time and improve the stability of the system. In the inner current loop control, turn the PI control of d/q rotating coordinate system into the PR control of two-phase static coordinate system, reduce the harmonic of the output and improve the robustness of the system. The simulation of the three phase voltage-source PWM rectifier model is carried out with the software MTALAB and the simulation results verify that this design method is feasible and the simulation model is correct.