Converter device used for wind generator system

Abstract

The invention discloses a converter device used for a wind generator system. The converter device comprises a filter, a first converter, a second converter, a first capacitor and a second capacitor, wherein the filter is connected to a wind-driven generator of the wind generator system; the first converter is connected to the filter; the second converter is connected to a voltage transformer on the power network side; and the first capacitor and the second capacitor are connected in series between a positive direct-current bus and a negative direct-current bus which are used for connecting the first converter and the second converter, neutral points of the positive direct-current bus and the negative direct-current bus are connected, and nodes of the first capacitor and the second capacitor are grounded.

Description

technical field [0001] The present invention relates to a converter device of a wind power generation system, more specifically, to a converter device capable of reducing the common-mode voltage of a converter of a wind power generator set. Background technique [0002] At present, the megawatt doubly-fed wind power generation system and the direct-drive wind power generation system generally adopt such as figure 1 and figure 2 The shown back-to-back dual PWM converter is used as a power converter, which uses power electronic switching devices. [0003] exist figure 1 and figure 2 In the wind power generation system shown, the filter 10 (for example, du / dt filter) is used to reduce the common-mode and differential-mode voltages on the generator side, and the converter 20 on the generator side has a double-fed generator (DFIG) Or the permanent magnet generator (PMSG) provides the function of AC excitation, and the voltage equalizing resistors 30a and 30b connected in se...

AI Technical Summary

Problems solved by technology

For doubly-fed generators, high common-mode voltage will generate shaft voltage and bearing current through the coupling capacitance between the stator and rotor, causing bearing damage and reducing the service life of the motor

In addition, high-frequency common-mode voltage will also generate high-frequency ground leakage current through parasitic capacitance, resulting in electromagnetic interference (EMI), affecting the normal operation of other electrical equipment in the system

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