English 
For the characteristics of wind power systems, a PWM inverter control system is designed in parallel with the power grid, which adopts current instantaneous value feedback control, directly takes the power network voltage synchronous signal as the inverter output current tracking instruction, and through the closed-loop follow control of the network side current, realizes the power factor of the unit power supply to the grid. The stability of the system is analyzed, and the experimental results prove the feasibility and correctness of the inverter control system.
With the strengthening of environmental awareness and the demand for renewable energy, wind power generation technology has been paid more attention to. Because of the instability and randomness of wind power, the electric energy emitted by wind turbines is the alternating current of voltage and frequency, and it is necessary to take effective power conversion measures before the wind power can be fed into the power grid. In order to improve the performance of wind turbine generator system, a variable-speed wind power system based on AC-DC-AC converter has been developed in recent years.
In the AC-DC-AC variable-speed wind power system, the control technology of inverter is the key, and the research work is carried out at home and abroad. The literature [2]~ literature [5] has a special study on it. In this paper, a new inverter control scheme is proposed by synthesizing the advantages of the inverter in these literatures. The inverter directly takes the power network voltage synchronous signal as the output current of the inverter, which can make the output current to track the power grid voltage quickly. The control system is simple in structure, the test result shows that the control system can realize the output of unit power factor and the harmonic content of output current is low.
