Reactive power control system and control method suitable for voltage control of grid-connected point of wind farm

Abstract

The invention relates to a reactive power control system applicable to wind farm grid-connection point voltage control and a reactive power control method applicable to the wind farm grid-connection point voltage control. The system includes a scheduling system; the scheduling system is connected wind a wind farm AVC system; the wind farm AVC system is connected with a wind farm concentrated SVC, a measuring device and a fan SCADA system respectively; and the fan SCADA system is connected with fans in a wind farm. The control method comprises the following steps that: the sequence of reactive power output adjustment performed on the fans by an AVC system is determined according to the sensitivity of wind farm grid-connection point voltage; and the total number of reactive power controllable fans is determined according to whether the reactive power of each fan is controllable or not, such that the upper and lower limits of adjustable reactive power total quantity of the fans can be determined; and reactive power total quantity Qreg of the wind farm, which is required to be adjusted, can be determined, and the Qreg is distributed according to a fan-first and SVC-second reactive power distribution strategy. With the reactive power control system and method applicable to the wind farm grid-connection point voltage control of the invention, the defect of long control cycle of the AVC system in the wind farm can be eliminated, and fast response adjustment ability of the SVC can be given to full play.

Description

Technical field: [0001] The present invention relates to a reactive power control system and a control method, and more specifically to a reactive power control system and a control method suitable for voltage control of a grid-connected point of a wind farm. Background technique: [0002] In recent years, under the pressure of energy crisis and environmental pollution, wind power, as a clean and renewable energy, has developed rapidly in power generation. With the continuous increase of installed capacity of wind farms, the safe and stable operation of grid-connected wind farms and the power grids in the connected areas has attracted increasing attention. One of the important aspects is that random changes in wind power power pose a threat to the voltage stability of local power grids. The large-scale wind power grid connection will cause grid voltage fluctuations, especially the voltage fluctuations at the grid connection points of wind farms are the most prominent. In or...

AI Technical Summary

Problems solved by technology

This will cause two problems. One is that each control process needs to collect the information of the fan and SVC, and then perform calculations and issue control commands. Communication delays cause a relatively long control cycle and affect the control effect; Passively receiving commands issued by the AVC system for control greatly limits the ability of the SVC device to quickly adjust and respond to voltage. Third, the reactive power of the fan is frequently adjusted, which affects the safe and stable operation of the fan itself.

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