Normally, an uninterruptible power supply (UPS) system supplies to AC lands if the national utility grid fails to supply AC source to the AC loads. The UPS system stands on the national utility grid. It means that it can be operated only in the area or near the national utility grid. It can be operated in the rural area, whereas it is very important to design an UPS system which can operate both in the national utility grid and also in the rural area. This paper presents a photovoltaic (PV) powered UPS system that can operate in both in the national utility grid and also in the rural area. A changeover of transfer switch is designed to control changeover of AC load sources. An analysis of AC voltage waveform should be considered to fulfill the standard of IEC 62040-3.

AC voltage waveform, UPS, photovoltaic.