THE TESTING OF PROTECTIVE RELA YS USING THE HYSTERESIS BAND CONTROL

The paper presents a new method for amplification of the necessary current in order to test electromagnetic relays.The current amplifier is based on a switch-mode voltage source inverter(VSI) with hysteresis band control. Here, a theoretical basis for the method Is described first, then a practical prototype of the current amplifier designed and built according to the method. the practical results given from the equipment are illustrated. Also computer simulation for the current amplifier as well as the real one(pracdcal equipment ) is done. A comparison between the computer simulation and the result of the real one is made and analyzed, The built current amplifier successfully applied onan overcurrent electromagnetic relay with the inverse characteristics. The results have given in the renal part of the paper.