Control method for low-voltage operation of wind generating set

Abstract

The invention discloses a control method for low-voltage operation of a wind generating set. The control method comprises the following steps of: detecting the voltage of a low-voltage power supply of a transformer through a low-voltage detection unit, transmitting the voltage state signal to a controller, meanwhile, reading the operating state signal of a fan through the controller, judging the generating power state of the wind generating set through the controller according to the voltage state signal and the operating state signal of the fan, and then sending corresponding control instructions. By the method, the utilization rate of the fan can be furthest improved under the condition of low voltage, and a power grid system is protected.

Description

technical field [0001] This application is a divisional application with an application date of September 4, 2009, an application number of 200910306601.4, and an invention title of "A Control Method and Device for Low-Voltage Operation of Wind Power Generating Sets". technical field [0002] The invention relates to a control method of a wind power generating set, in particular to a control method for low-voltage operation of the wind generating set. Background technique [0003] In recent years, the proportion of wind power generation in the power supply has grown rapidly. After the power grid fails and the voltage drops, if the wind turbines are disconnected from the power grid one after another, the system state will be unstable and may cause partial or even complete system failure. Therefore, people have begun to pay attention Low Voltage Ride Through (LVRT) method for wind turbines. [0004] In order to make wind turbines have low-voltage ride-through capability, pa...

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Problems solved by technology

[0004] In order to make the wind power generating set have low voltage ride-through capability, passive protection schemes such as placing discharge circuits in the inverter are mostly adopted at present. These methods increase the complexity of the equipment and the cost of the equipment itself, and the protection effect is relatively poor

[0005] In addition, in the case of low wind speed, the control method of the existing wind turbine is not to change the pitch of the wind turbine rotor, but to adjust the speed by adjusting the torque of the frequency converter; in the case of high wind speed, the existing wind turbine The control method is to limit the power by changing the pitch of the wind turbine rotor

This control method improves the efficiency of the wind turbine and reduces the load of the wind turbine, but it does not consider how to control it under low voltage (for low voltage, the State Grid Corporation of China has detailed regulations on how to connect wind farms to the power grid).

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