Abstract: Abstract:When the electric braking device is used to stop the hydrogenerator, the negative overload protection tripped incorrectly and gave relevant signal. Starting from multiple angles, which include the principle of negative sequence overload protection of generator, the principle of electric braking and the sampling principle of protection devices, the reason of the false trip accident was analyzed. The influence of the generator electric braking on the negative overload protection operation of the generator was summarized.

Key words: Keywords:electric braking, negative sequence overload, negative sequence filtering, relay protection setting