What is UPS？Construction Of UPS

UPS is an acronym for Uninterrupted Power Supply. This means that UPS is an alternative power source which gives interruption free supply of power to the load. ?UPS supplies the power?continuously to the lead?whether main supply OFF or ON. The main application of the UPS is that it provides power to load in the absence of Main supply or any interruption in main supply. The source of energy of UPS are batteries. The back up time (For how much time UPS can supply power to load in the absence of main power supply) depends upon the type and quantity of batteries used.

Mainly UPS consists of the following elements as shown in block diagram:

1. Rectifier (Battery Charger )
2. Battery
3. Inverter
4. Static Switch or Contactor

Rectifier: As we all know that the main function of rectifier is to convert alternating input supply to D.C. which will be used to charge the battery and then fed to inverter circuit. Its output may depends upon the load requirement.

Battery: The storage battery is used to store energy for future use in case of main supply failure. This battery may be lead acid or any other type depends on the requirement.

Inverter: It does the invert process of rectifier. It converts the incoming D.C. supply to alternating power supply for the use of load. The output of inverter is sine wave. It converts D.C. to A.C. of constant frequency and amplitude. The output of Inverter may contain harmonics which can be eliminated by using external circuit or special type of inverters.

Static Switch or Transfer Switch: A static switch or transformer switch is required to change over the circuit that is to transfer the source of power. The operation of this time should be very fast. Generally, the switches having switching time within 10 milli seconds are used.