Modeling And Maximum Power Point Tracking (MPPT) Control Of Direct-driven Permanent Magnet Synchronous Generator (D-PMSG)

Nowadays,the low-speed Direct-driven Permanent Magnet Synchronous Generator (D-PMSG) grid-connected wind turbine becomes one of the hotspots of wind power generation technique research. On the basis of the contrast existing four kind of common wind-power system structure and performance's, This paper will establish completely mathematical model of low speed D-PMSG system, and conducts the research to its high efficiency variable current electric circuit's topology structure and its power optimum control strategy.At first ,this paper introduces the work principle, subassemblies,performance and sorts of grid-connected wind turbine. Then, it compares the existing four categories VSCF wind generator systems of various kinds of structural characteristics, advantages and disadvantages, and then that low-speed permanent magnet synchronous generator directly wind-driven generators superiority. And concludes that the direct-driven PMSG wind turbine is the best choice. On the base of comparing five kind of wind-driven generator system structure and four type variable current electric circuit topology applied in it in briefly, This paper advances a main circuit which is based on IGBT's power grade nowadays and In operating performance situation, which is applied in high power direct-driven grid-connected wind turbine. It is made up of a three-phase rectifier, two paralleled BOOST chopper circuits and one PWM inverter. This paper analyzes their work principle and obtains the mathematical model of this kind of system structure in the summary to the existing system model's foundation. For the confirmation model's reliability, the article chooses 1.2MW D-PMSG system, tests its performance and the frequency conversion performance under its rated condition, and has confirmed the modeling reliability and the accuracy through the simulation.After completed low-speed D-PMSG system mathematical model, the article summarized the D-PMSG 's characteristic and the low speed frequency conversion characteristic, in accordance with the operation of D-PMSG Maximum Power Point Tracking(MPPT)control objectives and requirements, used the artificial neural network (ANN) controller for the variable pitch system and power feedback PI control to this kind of syetem. And carries on the simulation in the conditions of common gradual wind and random wind conditions separately in the Matlab simulation software, the simulation result indicated that the reliability and accuracy of timeliness with the artificial neural network (ANN) controller for the D-PMSG system.