Day 15: UPS (Cont'd)

The UPS specifications could be divided into 3 types :-

Standby Mode UPS

For Standby Mode UPS, the power current went through the surge compressor and filter to the Transfer switch in normal operation. During the failure operation, the transfer switch will tap on the other route, the battery will release current to flow through the inverter to the transfer switch and finally to the desired load. In this operation, the battery is classified as secondary source which put on standby, and release the power during the failure situation.

Line Interactive UPS

For Line-Interactive UPS, the designed is completely different since the inverter are connected as a hub to all the connections. This connection include the i/p, secondary input and Output. Since the output are connected directly at the inverter, the response of the system is improved. it means, the switch time is reduced when the failure situation occurs. An AC input will go thru the inverter, charge the battery and the flows to thr inverter back to the output terminal. If failure situation occur, the transfer switch will be disconnected, and the charged power stored inside the battery will act as a source to the output load.

 Standby-Ferro UPS

The structure of the Ferro-standby UPS is approximately the same as the normal standby UPS. The only difference, is the use of transformer instead of using a normal switch. There transformer act as a buffer which links between the primary, secondary and the load. the output windings, will determine the input to be choose. during the normal operation, it will choose the primary and vice versa during the outage situation.