Transformer Tap Changer

The tap changer is a tool changer for voltage transformation ratio of secondary operations that are better than the network voltage / primary changes.

There are two ways of working tap changer:
1. Changing the tap in a state of no-load transformer. Tap changer that can only operate to move the transformer tap transformer in a state of no load, called "Off Load Tap Changer" and can only be operated manually

2. In a state transformer tap changing under load. Tap changer that can operate to move the tap transformer, the transformer under load condition, called "On Load Tap Changer (OLTC)" and can be operated manually or automatically

Transformer installed in substations in general use tap changer that can be operated in a state of the transformer under load and mounted on the primary side. While penaik voltage transformer in a power transformer capacity or in small, generally using the tap changer is operated only during power transformer no-load.

OLTC composed of:
1. Selector Switch
2. diverter switch
3. transition resistors

To isolate the transformer from the body (ground) and to reduce heat during the process of moving the tap, then OLTC immersed in insulating oil are usually separated from the main isolation transformer oil (there are some transformers that compartemennya become one with the main tank).

Because the transfer process in the oil tap relationships happened electrical phenomena, mechanical, chemical and heat, the insulation OLTC oil quality will quickly decline. depending on the amount of work and the presence of abnormalities in the OLTC