Control method for large wind field reactive-load compensation equipment in low voltage ride through

A technology for low voltage ride-through and compensation equipment, which is applied in reactive power compensation, AC network voltage adjustment and other directions, and can solve problems without considering economy and practicability.

CN103368184AActive Publication Date: 2013-10-23STATE GRID CORP OF CHINA +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Publication Date
2013-10-23

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Abstract

The invention discloses a control method for large wind field reactive-load compensation equipment in low voltage ride through. The control method comprises the follow steps that firstly, information of voltage, current, power and frequency in a power grid is sampled through coordination control of an automatic voltage control system, fault points are detected, and when draught fan low voltage ride through starts, a static var generator is rapidly started to provide reactive power; secondly, compensation capacity of various types of reactive-load compensation equipment is determined according to different installation places and effects of the reactive-load compensation equipment and different principles; thirdly, the static var generator respectively achieves the reactive compensation work state and the harmonic suppression work state by using different control strategies; fourthly, the automatic voltage control system starts a thyristor switched capacitor when power voltage is equal to pre-charged voltage of the thyristor switched capacitor; fifthly, the automatic voltage control system starts a thyristor controlled reactor according to reactive gap information; the fourth step and the fifth step are in parallel with each other.
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Description

technical field

[0001] The invention relates to a power system control technology, in particular to a control method for reactive power compensation equipment in which a wind turbine enters a low-voltage ride-through stage after a voltage slump occurs in a wind farm. Background technique

[0002] At present, as the proportion of wind power installed capacity in the grid is getting higher and higher, the scope of influence of wind power on the grid is gradually expanding. At present, wind power grid-connected has different characteristics from the past, which are manifested in the following three points:

[0003] 1) The capacity of a single wind farm continues to increase.

[0004] 2) In the power grid with large wind power penetration, because the wind power injection changes the original power flow distribution of the grid, the line transmission power and the inertia of the entire system, the voltage stability, transient stability and frequency stability of the grid will a...

Examples

Embodiment Construction

[0074] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0075] At present, asynchronous wind generators and doubly-fed asynchronous wind generators occupy a large share in the market, and the present invention is mainly based on these two kinds of wind generators for research.

[0076] Asynchronous wind turbines generally do not need converter equipment, and are directly connected to the power grid through transformers. It needs to absorb certain reactive power from the grid during operation. Its simplified mathematical model is:

[0077] Q = r 2 + x k ( x k + x m ) ...