MPPT Control For Direct-Drive PMSG Based On Adhdp Method

High-power low-speed direct-drive permanent magnet synchronous generator (D-PMSG) is the mainstream direction of the wind motor in recent years. Power generation efficiency and the output power quality of the wind motor are severely affected by the randomness and instability of wind power. The maximum power point tracking (MPPT) control is an important way to get the maximum wind energy and ensure the stability of output power for wind motors. The wind turbine is a complex nonlinear system with random interference and it is quite hard to build its precise mathematical model because the wind load changes frequently, thus it is difficult to meet the requirements of the tracking control by the traditional control methods. Therefore, it is important to study an effective way to deal with the MPPT control problem of permanent magnet direct-drive wind turbine, so as to develop the power generation efficiency and output power stability.At first, the research status of wind turbine control technology are analyzed, MPPT control problem of wind turbine and adaptive dynamic programming method are introduced. Then the action dependent heuristic dynamic programming (ADHDP) algorithm is proposed to deal with MPPT control problem of wind turbine. ADHDP method is able to train and update online, optimize the controller and adjust the controller output automatically without a precise mathematical model. Secondly, the mathematical model of permanent magnet synchronous generator is discussed and a3.2MW Simulink model of variable speed direct-drive wind turbines is set up in Matlab/Simulink. Finally, the MPPT controller of D-PMSG based on ADHDP is designed, simulation experiments are studied to compare with traditional PID control method. Simulation results show that the ADHDP controller is able to achieve maximum power tracking. Besides, it shows better robustness, faster dynamic response and convergence speed, which solves the slow steady-state output power and steady state error and other issues occur in traditional control methods. The wind turbine power generation efficiency has improved significantly.