Low voltage ride through (LVRT) control system of fixed-blade stalling type wind generating set

Abstract

The invention relates to a low voltage ride through (LVRT) control system of a fixed-blade stalling type wind generating set. The LVRT control system comprises a thyristor switched capacitor (TSC) type static var compensator (SVC), a revolution speed transducer and an intelligent controller, wherein the revolution speed transducer is installed on a squirrel-cage asynchronous generator; the intelligent controller is used for realizing LVRT control; the TSC type SVC is connected to the three-phase line of the squirrel-cage asynchronous generator and comprises n numbered groups of capacitors which are connected in parallel, and a single group of capacitors are connected with a bidirectional thyristor in series; and the intelligent controller comprises a revolution speed acquiring module, a revolution speed impedance characteristic computing module and a capacity allocating module, the revolution speed impedance characteristic computing module is used for computing the target equivalent capacitive impedance according to revolution speed signals and the inherent characteristic parameters of a motor, and the capacity allocating module is used for allocating each group of capacitors needing to be put into operation according to the computed target equivalent capacitive impedance and sending a closing instruction to the corresponding bidirectional thyristor. According to he invention, good control effect is realized on the premise of lower cost.

Description

technical field [0001] The invention relates to a fixed-blade stall-type wind power generating set, in particular to a low-voltage ride-through control system. Background technique [0002] The low-voltage ride-through capability of wind turbines refers to the ability of wind turbines to maintain grid-connected operation when the terminal voltage of wind turbines drops to a certain value. [0003] The voltage sag caused by the transient short circuit of the grid system often occurs in actual operation, and most of the faults can be recovered within a short time (usually no more than 0.8 seconds) under the control of the relay protection device. That is, reclosing. In this short period of time, the grid voltage drops sharply, and the wind turbines must make reactive power adjustments in a very short period of time to support the grid voltage, so as to ensure that the wind turbines are not disconnected from the grid, and avoid a large number of wind power components in the lo...

AI Technical Summary

Problems solved by technology

[0012] In order to overcome the shortcomings of the low voltage ride-through control method of the existing fixed-pitch stall type wind turbine generator set that cannot take into account both cost and control effect, the present invention provides a fixed-pitch stall type wind power generator that can achieve good control effect under the premise of relatively low cost. Low Voltage Ride Through Control System for Generating Sets

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