Online UPS

At present every organization needs 100 percent availability of power. But it is very tough to maintain zero downtime of the power supply. Some of the organizations like hospitals, information security, etc. are serving critical services where the absence of power supply is not acceptable even for 5 minutes. To solve this problem many organizations use their power backup generators. But these backup generators run on fossil fuels like diesel and petrol that cause environmental pollution. One alternative of these power generators is “Online UPS”.

What is Online UPS?

We are already aware of the word UPS that simply represents “Uninterrupted Power Supply”. If don’t, let me remind you, in your old personal computer there is a power backup unit that provides a power supply in absence of mains power. When an incoming power failure occurs then only backup batteries connect to the inverter circuit to generate AC power by using DC power. But “Online UPS” is slightly different from this conventional uninterrupted power supply unit. In an Online UPS, the backup batteries are always connected to the inverter circuitry (DC to AC converter circuit), as of result, it is not necessary to have a power transfer switch or a relay unit (power transfer switch is responsible to connect backup batteries to inverter circuit only on the absence of the main power). In Online UPS when mains power failures, the rectifier circuit (AC to DC converter circuit) just drops out of the circuit and the batteries keep the flow of power steady and unchanged.

Online UPS working diagram

Online UPS working diagram

When mains power comes back, the rectifier circuit resumes carrying most of the load and also starts charging the backup batteries. In most Online UPS, charging current is limited by the high power rectifier circuit to prevent overcharging or heating to backup batteries. The most important significance of the Online UPS over other UPS is its ability to provide an “Electrical Firewall” or “Electrical Surge Protector” between the incoming utility power and sensitive electronic equipment at the load end.

What is inside this gadget?

An Online UPS contains several electronic circuit units. We will see each and every important unit of this gadget. Have a look at below technical parts:

  1. Rectifier
  2. Inverter circuit
  3. Static switch
  4. Display panel
  5. Cooling unit
  6. Backup batteries