@thesis{thesis, author={KURNIAWAN DEDI and Samsurizal Samsurizal}, title ={PENYETTINGAN PROTEKSI GENERATOR LOSS OF FIELD RELAY PLTA BESAI 2 x 45 MW}, year={2019}, url={http://156.67.221.169/1793/}, abstract={One disturbance that occurs in synchronous generator is interference with loss of excitation field. This disruption occurs when the generator excitation current is lost due to damage to the excitation system, while the generator is still connected to the electrical grid, causing the reactive power generated by the generator to be reduced or even lost so that the generator will draw reactive power from the electrical network system and act as an induction generator. Disturbances in the loss of the generator field can cause damage in the form of damage to the stator coil, damage to the insulation and the stator core ends, causing interference with the ground connection. So to anticipate the impact of the disturbance a protection system is needed. The protection system used in the BTA unit # 1 hydropower is the Mho offset relay. From the research calculations there are 2 protection zones, namely zone 1 and zone 2. For zone 1 the excitation failure is at 1 pu with a delay time of 0.5 seconds, while for zone 2 the excitation failure occurs at a value of 2,140 pu with a delay time of 2,0 seconds, while the value of Mho relay offset in zone 1 and zone 2 will work at a setting value of 0,122 pu with a delay time of 0,5 seconds.} }