Topology structure of machine-side converter of a permanent magnet direct-drive wind generator and control method

Abstract

The invention relates to a topology structure of a machine-side converter of a permanent magnet direct-drive type wind generator and a control method, belonging to the technical field of wind power generation. The topology structure comprises a Vienna rectifier, a DC / DC boost converter, one end of the Vienna rectifier is connected with a stator of a permanent magnet direct-drive wind generator, and the other end of the Vienna rectifier is connected with a DC / DC boost converter. The other end of the DC / DC boost converter is connected to the DC bus. The control method is as follows: the Vienna rectifier adopts zero-sequence component injection method to realize harmonic minimization of generator; the DC / DC boost convert realizes boost and maximum power point tracking control of wind turbines. The invention overcomes the defect of high spike voltage pulse inherent in the traditional voltage source converter, reduces the insulation requirement of the generator stator, simplifies the manufacturing process of the generator and reduces the cost. Small current harmonics avoid additional mechanical vibration and torsional vibration phenomenon, switching devices withstand low voltage, and the structure and the method are especially suitable for high voltage, and high power applications.

Description

technical field The invention relates to a converter, in particular to a topology structure and a control method of a permanent-magnet direct-drive type wind power generator machine-side converter, and belongs to the technical field of wind power generation. Background technique The traditional permanent magnet direct drive wind turbine generator side converter generally adopts uncontrollable rectifier + Boost combination or voltage source converter VSC topology. The uncontrolled rectifier will cause a large number of harmonics, and the harmonics in the stator current will cause ripples in the torque waveform of the generator, and the torque ripple may also cause additional mechanical vibration and torsional vibration of the wind turbine. For the voltage source converter VSC, although it is a controllable rectification, the high peak voltage pulse caused by its du / dt will cause a great threat to the insulation of the stator winding of the generator, which makes the motor to ...

AI Technical Summary

Problems solved by technology

The uncontrolled rectifier will cause a large number of harmonics, and the harmonics in the stator current will cause ripples in the torque waveform of the generator, and the torque ripple may also cause additional mechanical vibration and torsional vibration of the wind turbine

For the voltage source converter VSC, although it is a controllable rectification, the high peak voltage pulse caused by its du / dt will cause a great threat to the insulation of the stator winding of the generator, which makes the motor to be completely in accordance with the high voltage generator design, which increases the insulation thickness of the winding and the cost of the motor, and deteriorates the heat dissipation of the motor

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