What is a Tcul transformer?
Most transformers come equipped with taps on the windings to adjust either the voltage transformation or the reactive flow through the transformer. Such transformers are called either load-tap-changing (LTC) transformers or tap-changing-under-load (TCUL) transformers.
What is Tcul?
If voltage is to be regulated in the substation, the most economical method is with tap changing under load (TCUL), sometimes referred to as LTC or load tap changing, built into the transformer.
What is an LTC transformer?
Load tap changers (LTCs) play an important role in a substation. These mechanical devices are often overlooked, but a failed LTC will cause problems at its substation and complications through the grid as load is rerouted. LTCs are often tested and maintained by the same crews that test circuit breakers.
How can three phase transformation be accomplished using only two transformers?
The Scott T connection are employed 2 transformers to transform 3 phase power to 2 phase power at different voltage values. Through a normal variation in the connection, the similar 2 transformers can transform 3 phase power to 3 phase power for values. These connections can seen here.
What is Rtcc and Oltc?
RTCC stands for Remote Tap Changer Control. It is used to control the transformer output voltage by controlling the OLTC unit of the transformer. As we know the OLTC (On Load Tap Changer) is responsible to change the transformer output voltage.
Why are transformer tappings on the HV side?
Mostly the power transformer is used for both step up and step down action. In that, the power transformer’s turns are in the high voltage side is higher than the low voltage side. Therefor placing on load tap changer circuit on high voltage side which give fine voltage regulation.
What happens if one phase of a 3-phase transformer fails?
Effect of Single Phasing or One Phase Failure on Three Phase Machines. Electrical machines will operate at a considerably reduced speed, under power and produced toque. Due to the loss of one phase, the current in the other two phases will increase.
Why Oltc is used in transformer?
On-load tap changer (OLTC), also known as On-circuit tap changer (OCTC), is a tap changer in applications where a supply interruption during a tap change is unacceptable, the transformer is often fitted with a more expensive and complex on load tap changing mechanism.
What is Oltc in transformer?
There are two types of transformer tap changers: an on-load tap changer (OLTC) and a deenergised tap changer (DETC). Note that not all transformers have tap changers. An OLTC varies the transformer ratio while the transformer is energized and carrying load.
Where are the tappings provided in a transformer?
Detailed Solution. Normally the tapings are provided at the middle of high voltage winding due to the following reasons, 1) Fine voltage regulation is possible with high voltage winding as it carries a large number of turns. 2) The low voltage winding of the transformer carries a large current.