Back-to-back three-power level midpoint clamping current transformer of wind power generation system

A technology of wind power generation system and converter, which is applied in the direction of wind power generation, conversion equipment for intermediate conversion to direct current, conversion of AC power input to AC power output, etc., which can solve the problem of high harmonic content and low capacity of converters etc. to achieve low harmonic content, realize high-power transmission, and reduce waveform distortion rate

CN101316074BInactive Publication Date: 2011-08-10INST OF ELECTRICAL ENG CHINESE ACAD OF SCI +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2011-08-10
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention provides a back-to-back three-level midpoint clamp converter in a wind generation system, comprising a rectifier beside a motor and an inverter beside the network; an AC input terminal is connected with a stator side output terminal of a permanent magnetic synchronous generator; the output terminal of the inverter is connected with an electricity grid. The output of the rectifier isconnected with the input of the inverter; the midpoints of the rectifier and the inverter behind a diode clamp are connected with each other; the rectifier and the inverter require the control of a digital signal processing chip DSP. The back-to-back three-level midpoint clamp converter utilizes the three-level rectifier and the inverter of the midpoint clamp in the diode, increases the capacity of the wind generation system by a space vector controlling method, and obviously improving the shape of the voltage waveform output to the electricity grid so as to be adapt to the standard of the parallel electricity grid more excellently.
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Description

technical field

[0001] The invention relates to a back-to-back three-level mid-point clamp converter in a wind power generation system. Background technique

[0002] In recent years, multilevel converters have attracted widespread attention from scholars at home and abroad in the field of high voltage and high power. The idea of ​​a multilevel converter was first proposed by Nablae et al. in 1981. Its basic idea is to synthesize a step wave by several level steps to approximate a sinusoidal output voltage. As a new type of high-voltage and large-capacity power converter, the multi-level converter starts from the circuit topology. While obtaining high-quality output waveforms, it overcomes many shortcomings of the two-level converter. It does not require output transformers and Dynamic voltage equalizing circuit, low switching frequency, low stress on switching devices, high system efficiency and other advantages.

[0003] With the increase of the capacity of the switching ...

Examples

Embodiment Construction

[0023] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0024] Such as figure 1 As shown, the direct-drive wind turbine includes a wind turbine, a generator, a wind turbine rectifier, a DC side capacitor, a DC side unloading circuit, a grid side inverter, a grid side filter inductor and a grid. The back-to-back three-level neutral-point clamping converter of the present invention includes a fan-side rectifier and a grid-side inverter. The three-phase wires of the stator of the wind power generating set are respectively connected between the switching tubes S2 and S3, between S6 and S7, and between S10 and S11. The output of the rectifier and the input of the inverter are connected at points A and B, such as figure 2 shown. Like the input of the rectifier, the output of the inverter is connected to the grid G ​​after passing through the inductor L.

[0025] figure 2 It is the topological stru...