Trouble shooting of generator differential relay operation using digital simulators

This paper gives an example of the proformers [5-6]. Once the models are made available, tective re1a.y operation evalua.tion using digital simdigital simulations producing quite accurate waveulators. A generator differential relay protecting a forms corresponding to actual faults and other tran1500 MVA generator was found to he tripping under sient opera.ting conditions ca.n be carried out. Digin-rush current conditions ca.used by energizing an ital simulators ena.ble replaying of these waveforms adjacent power transformer. A digital siinuhtor was into relays for deta.iled evaluation of the relay perused to recreate the conditions using Electroimgforimiice. netic Transient Program (EMTP) simula,tion. The waveforms generated by the simulator were a.pplied This pa,per gives a.n example of the use of digital to trouble shoot the relay opera.tion. It was also used simula.tors in eva1ua.ting operation of various differto test two more relays to finally select the one that ential relais. The simulator is first used to troublewill not be sensitive to the inrush conditions. shoot a.n undesired relay opera,tion under inrush current conditions. After tha t , two other relays are eval