Reaearch On Control Strategy Of Low Voltage Ride-through In Direct-driven Wind Turbine System

With the increasing development of social economy, science and technology, it is increasing everyday of social demand for energy. It is becoming much stronger for the environment protection consciousness of human beings, so the development of new energy is imperative. Wind power has a clean and environmental protection, investment flexibility and good economic benefit among many different kind of new energy.The following work are mainly done based on direct drive wind power system low voltage through technology research.First is the basic theory research. These research includes the basic principle of three-phase voltage source of PWM converter and the mathematical model under the static coordinate system and the rotating coordinate system, the control strategy of grid side converter in the direct driving type of wind power.The second, the control strategy are analyzed and summarized for direct-drive network side converter, a fuzzy adaptive PI controller is designed, the network side of the double closed loop control strategy of the converter is discussed, and different control methods of dc unloading branch are analyzed during the period of LVRT and reactive power compensation control strategy.Third, set up a Matlab simulation model to the permanent magnet synchronous motor for the1.5MW double back-to-back PWM converter, validate network side converter control strategy.Finally, according to the Simulink simulation model, designed a set of application software on DSP.