Impact of Solar Photovoltaic System on Transformer Tap Changer in Low Voltage Distribution Networks

This paper investigates the impact of solar resource variability on the operation of a low-voltage On-Load-Tap-Changer (OLTC) in a generic distribution network from the Malaysian grid. The OLTC's operation is studiedin two different weather conditions-sunny and cloudy days. The aspects analysed are the OLTC's time delay setting, PV penetration levels and PV installation location. The results suggest that the number of tap changes in a cloudy day is approximately 1.5 times higher than in a sunny day. In addition, at 50% PV penetration level on a cloudy day, the OLTC operation increases by 38% and it is doubled at 100% penetration.