Research and implementation of inverse time overcurrent protection algorithm for engine interface unit

The engine reverse thrust control is of great significance to the landing deceleration of the aircraft. The action time of inverse time overcurrent protection changes with the size of the current, and the protection of the upper and lower levels has a high adaptive ability, which can quickly cut out the fault near the power side. Compared with the stage current protection, it can better meet the dual requirements of quick movement and selectivity of the distribution network, and when the system operation mode changes, its selectivity and sensitivity will not change greatly. Aiming at the electrical characteristics of load and interface, an inverse time limit overcurrent protection method is proposed, which uses the protection mechanism of I2T curve theory. The inverse time limit current protection action time changes with the input current. When the input current exceeds the set threshold, the protection mechanism will be activated to achieve better protection performance.