Generator system for wind power generation and variable speed control method

Abstract

The invention discloses a generator system for wind power generation and a variable speed control method; the system comprises a permanent magnetic synchronous generator of which the electrical energyoutput is connected with a Vienna rectifier device, and is characterized in that a stator winding of the permanent magnetic synchronous generator comprises two sets of triphase windings with electrical degree difference of 180 degrees and unconnected neutral points thereof; the Vienna rectifier device comprises two Vienna rectifiers with identical structure, which are in parallel connection withthe DC side with a central point O connected with a DC bus capacitance midpoint; the AC side is connected with the two triphase windings of the generator respectively; a Boost inductance of the Viennarectifier is directly provided by the leakage inductance of the windings of the generator; each Vienna rectifier device is controlled by a DSP controller to maintain the balance of the DC bus voltageby the phase current and line voltage collected in the AC side and the bus voltage collected in the DC side; and the variable speed control of the generator is realized by collecting the rotating speed of a fan and the current wind speed.

Description

technical field [0001] The invention relates to a generator system and a variable speed control method, in particular to a power generation system and a variable speed control method for wind power generation based on a 6-phase permanent magnet synchronous generator. Background technique [0002] In MW-level high-power direct-drive wind power systems, the generator is usually a three-phase motor, and the outlet voltage level is often lower than 690V. Due to the large stator current, the design of the full power converter on the stator side of the generator is Unfavorable, where harmonics and efficiency are two important issues. A conventional technical solution is to adopt a multi-pulse diode rectification scheme (for example, 12-pulse rectification), or to use two-level PWM rectifiers connected in parallel to share capacity. Of these two solutions, the former requires a phase-staggered transformer, and diode rectification will generate large harmonic currents for the gener...

AI Technical Summary

Problems solved by technology

Of these two solutions, the former requires a phase-staggered transformer, and diode rectification will generate large harmonic currents for the generator, causing torque ripple and motor heating problems; although the latter has better harmonic performance, it will Under the circumstances, it is an inefficient practice to connect two level rectifiers in parallel

In contrast, multilevel converters have higher efficiency and superior harmonic performance, but there is a problem of capacitor voltage balance control

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