1.Off line UPS in the normal power supply directly supply power to the load from the city power, when the city power beyond its work range or power is off, switch to the inverter power supply through the switch. Simple structure, small size, low cost, but the input voltage range is narrow, the output voltage stability accuracy is poor, there is a switching time, and the output waveform is generally square wave.
2.Online UPS when the normal city power is normal, city power supply DC voltage to the inverter, through the inverter supply alternating current to the load, when the commercial power is abnormal, the inverter battery provides energy to keep inverter always in working state. The characteristic is that it has a very wide input voltage range, no switching time and high output voltage stability, which is especially suitable for occasions with higher power requirements. At present, the power greater than 3KVA is almost 3KVA online UPS.
3.When the city power is normal, the city power supply electricity directly to the load. When the city power is low or high, through the online interactive UPS internal zener voltage regulator circuit output, when the city power failure or abnormal, via switch turn to inverter battery power supply. There is a wide range of input voltage, low noise, small size and other characteristics, but also exist switching time.
