A control method for preventing mechanical braking of hydropower station units from high-speed braking

Abstract

The invention relates to a control method for preventing the mechanical braking of a hydropower station unit from applying brakes at high speeds. Valve YV, monitoring system LCU, mechanical brake switching order signal output board and relay, the circuit is equipped with guide vane position signal contact, low speed signal contact, GCB position signal contact. The high-speed brake protection control logic is used to exit the mechanical brake when a high-speed brake accident occurs. The logic design is: when the speed measurement device of the governor is effective, the speed of the unit is greater than 20% of the rated speed, and the mechanical brake is activated. signal, delay 0.2S to switch on and off the mechanical brake, and block the mechanical brake to reduce equipment loss. This method is suitable for preventing the occurrence of high-speed braking accidents of hydropower generating units when the monitoring system is paralyzed, the mechanical brake input signal is issued by mistake, and the unit speed measurement is abnormal, etc. in the power plant.

Description

technical field [0001] The invention relates to a control method for preventing the mechanical braking of a hydropower station unit from applying brakes at high speeds. Specifically, when the monitoring system of the hydropower station is paralyzed, the monitoring system sends a mechanical brake input signal by mistake, and the unit speed measurement is abnormal, etc., A control method to prevent high-speed braking accidents of hydropower units. Background technique [0002] At present, the combined braking method is mostly used in the braking process of the hydropower station unit. During the normal shutdown process, the speed of the electric brake is 50%-60% of the rated speed, and the speed of the mechanical brake is generally 5% of the rated speed. 10%. Generally, if the mechanical brake is applied at a rate greater than 20% of the rated speed, it will be judged as high-speed braking. The high-speed braking of the generator will cause huge harm, causing equipment damage...

AI Technical Summary

Problems solved by technology

Generally, if the mechanical brake is applied at a rate greater than 20% of the rated speed, it will be judged as high-speed braking. The high-speed braking of the generator will cause huge harm, causing equipment damage such as generator fire and mechanical brake damage. The gate produces a large amount of dust, which adheres to the stator and rotor of the generator, making it difficult to clean and seriously affecting the insulation level of the generator

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