Research On Wind Farm Voltage/Reactive Power Coordinated Control And Low Voltage Ride Through

China’s wind energy resources are abundant, in recent years, with large-scale wind farm access to the power system, bring the hidden safe and stable problem to power system. And, because of the wind power grid technology limitations, the development of large-scale wind farm connected to the grid meets bottlenecks. Grid dropout accident of large-scale wind farm always happened because of the wind turbine generation do not have low voltage ride through capability. The safe and stable operation of power grid put forward new requirements to wind farm on reactive regulate, voltage control capabilities, low voltage ride through capability.This paper focus on the wind farm voltage stability, analyzed the mathematical model of Doubly Fed Induction Generator (DFIG) and Directly Driven Wind Turbine with Permanent Synchronous Generator (D-PMSG).For direct drive wind turbine, proposed a converter instantaneous power balance control strategy, introduce Instantaneous Power Theory to the wind turbine converter control algorithm, to improve the response speed of the reactive power. For DFIG proposed a Space Vector Pulse Width Modulation (SVPWM) control. Used Vector control, and achieved wind generator active power, reactive power decoupling control. Improved wind generator reactive power regulation capacity, and given full play to the wind turbines reactive support capabilities.According to wind farm connected to power system technical related requirements, comprehensive considered wind turbine reactive power regulation capacity and wind farm centralized reactive power compensation equipment. Established wind farm reactive power compensation coordinated control strategy, control target selection the busbar high side voltage of the point-of-common coupling of wind farm (PCC), determine the amount of wind farms need to compensate the reactive power according to the deviation between the measured actual bus voltage with a reference voltage, reasonable allocation of the amount of reactive power compensation in the wind farm layer and the wind turbine layer,achieved the low voltage ride through ability of a single wind turbine generation and the whole wind farm.Relying low voltage through device, based on impedance divider to set voltage drop to take low voltage ride through test on wind turbine generation. During the Voltage drop, compare and analyze the simulation results with the measured results, verify the correctness of wind turbine low voltage ride control strategy. Set a reasonable short circuit point on wind farm collector bus line, through short-circuit test tested the whole wind farm LVRT capability. Compare and analyze two control strategies simulation results, verify the correctness of this paper proposed wind farm voltage and reactive power coordination control strategy.