Abstract：The three-stage overcurrent protection plays an important role in the configuration of relay protection of auillary power system in the power plant. Aiming at the problem of differential coordination of three-stage overcurrent protection level, according to the sensitivity of different protection installation positions under the same fault, abstract features are extracted, the preprocessing format of fixed value data is developed, and the primary equipment and over-current are completed by using Simulink with the help of computer tools. Through fault simulation, the sensitivity of all levels of protection elements is obtained, and its differential coordination relationship is checked. The problems of differential time and sensitivity coordination are effectively and accurately located in the setting of factory power relay protection.
2020, Vol. 21 
