@thesis{thesis, author={Diantari Retno Aita and Novidiati }, title ={PENYETELAN AUTOMATIC VOLTAGE REGULATOR TERHADAP ON LOAD TAP CHANGER TRANSFORMATOR DAYA 150 KV / 20 KV DI PT. PLN (PERSERO) GARDU INDUK JATAKE}, year={2019}, url={http://156.67.221.169/1771/}, abstract={The power transformer at the substation is required to produce an output voltage on the secondary side that is constant and stable. The reality is that it is difficult to get a constant voltage which is caused, among other things: load fluctuations, losses in conductivity which have an impedance which causes a voltage drop. To maintain the output voltage on the secular side of the power transformer to remain constant and stable, a tap changer is installed on the power transformer and works manually or automatically for any changes in voltage. The working principle of the tap changer is to change the ratio of the primary winding to the secondary winding of the power transformer to get the secondary side operating voltage as desired. Thus the voltage of the secondary side of the power transformer can be adjusted to the system requirements, even though there are fluctuations in load and conductivity losses that cause voltage drops. Adjustment of AVR to OLTC with Vn of 20,000 volts, voltage deviation of 1.5%; Vr is 9 volts and VxL is 9 volts in LDC settings, setting undervoltage blocking function is -15%, setting overcurrent blocking function is 120%, setting overvoltage monitoring is 20%, voltage value per tap OLTC is in accordance with the measurement results of transformer III ratio, the amount of OLTC work in 24 hours is 40 times, and the tap transfer time with a 60 second time delay setting and 5 seconds highspeed switching time delay.} }