difference amongs PT,CVT,IVT
difference amongs PT,CVT,IVT
(OP)
HELLO ALL
MY QUESTION IS WHAT IS DIFFERENCE AMONGS PT, CVT AND IVT USED IN SWITCHYARD.CAN WE USE CVT INPLACE OF PT AND IVT,VISEVARSA.DEEPLY EXPLAINATION .
THANKS IN ADVANCE
MY QUESTION IS WHAT IS DIFFERENCE AMONGS PT, CVT AND IVT USED IN SWITCHYARD.CAN WE USE CVT INPLACE OF PT AND IVT,VISEVARSA.DEEPLY EXPLAINATION .
THANKS IN ADVANCE






RE: difference amongs PT,CVT,IVT
I am not familiar with the term IVT (inductive type?).
RE: difference amongs PT,CVT,IVT
RE: difference amongs PT,CVT,IVT
RE: difference amongs PT,CVT,IVT
RE: difference amongs PT,CVT,IVT
As the attachment describes, there are some limitations to exchanging a VT with a CVT. The attachment describes a CCVT, which has the ability to couple a communications signal on the line, used primarily for distance relay station to station communications, although there are other applications, such as blocking and direct transfer trip, etc. A CVT is the same without the additional components required to couple a communications signal. As noted, one concern of using a CVT in place of a VT is the performance under fault conditions (transient response). Most modern digital/numerical distance relays have a function which, when enabled, can compensate for this.
RE: difference amongs PT,CVT,IVT
RE: difference amongs PT,CVT,IVT
smallgeek...you're correct on the transient response issue. However, in actual practice, it rarely is an issue now, since the burden presented by electronic relays and meters is so low. Transient response performance improves as the burden is reduced. Also, as you mentioned, most relays can compensate for CVT transient response when set accordingly.
There is not uniformity in using CVT or CCVT. Most tend to use the terms interchangeably and use the term with or without "carrier accessories" to indicate if they can be used for power-line carrier coupling or not. BUt technically CCVT = coupling capacitor voltage transformer and CVT = capacitor voltage transformer. In reality, they are both the same devices, just carrier accessories include a drain coil, carrier ground switch, and choke coil.