Wind-driven generator set variable-pitch system power grid fluctuation protection method

Abstract

The invention relates to a wind-driven generator set variable-pitch system power grid fluctuation protection method. The method includes the following steps that: a wind power generation control system reads power grid AB line and BC line voltage which is detected by a converter and sends the voltage to a variable-pitch system through CANopen; the variable-pitch system receives the power grid AB line and BC line voltage sent by the wind power generation control system and judges the state of a power grid according to a set line voltage fault threshold value and fault delay time; when the power grid AB line and BC line voltage sent by the converter fails or communication between the variable-pitch system and the wind power generation control system is interrupted, the variable-pitch system detects bus-bar voltage through a driver and calculates energy switched onto a braking resistor in a period when a braking chopper is switched in, and the variable-pitch system indirectly judges the state of the power grid according to the set fault threshold value and fault delay time; if the variable-pitch system detects that the power grid is in abnormal state, a main power source contactor is switched off, so that the variable-pitch system can be disconnected from the power grid, and a backup power source executes emergency propeller feathering; and after the propeller feathering is completed, the variable-pitch system continues to detect the state of the power grid, after the power grid recovers normal power supply, the system operates normally.

Description

technical field [0001] The invention relates to a protection method for a pitch-variable system of a wind power generating set. Background technique [0002] As a highly efficient, clean and renewable energy, wind energy has been paid more and more attention by countries all over the world. China's new energy strategy has focused on the development of wind power generation. In recent years, due to the many advantages of wind energy and the strong support of national policies, the domestic wind power industry has developed rapidly. As the proportion of wind turbines connected to the power grid increases, the voltage and frequency of the power grid fluctuate greatly in different regions due to the influence of geographical location and transmission line factors. Ordinary wind turbines can adapt to grid fluctuations within the normal range, but conventional wind turbines cannot operate stably when grid fluctuations are severe, and the pitch control system is more seriously aff...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that when adding the power grid monitoring module, it is necessary to add related auxiliary equipment and detection circuits, which in turn increases the hardware failure points and design costs of the wind turbine. In addition, the normal operation of the power grid monitoring module and the accuracy and real-time performance of feedback information are affected by the working environment

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