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Differential Protection Scheme (Transformer)

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Hey friends! you are familiar with the power system equipment which we discussed earlier.! Now it's time to protect it to total safety. As soldiers protect our country from enemies likewise our system should be protected from fault. The line of control is decided by fixing the current transformers on the right place. So our boundaries is decided by their location. Here in a substation, we have many equipments such as transmission lines, bus-bar, transformers, etc in the system which need atmost care. Starting from the bulkiest, transformers are having different level of protections such as phase to phase and phase to ground. In other words differential protection and earth-fault protection. Over-current protection is also implemented in it. Let's talk about the differential type of protection for transformers. It's quite simple to explain the theory but some complicated while coming into the calculation. The term itself gives a brief idea about the ...

Potential Transformer

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It is very important to manage and measure the Extra High Voltage level which we use to transfer power from one point to other. Since the insulation gradient for Extra High Voltage(EHV) is very high, it is difficult to measure this high voltage. So for the measurement its necessary to reduce the voltage level.  Here we generate a reference voltage with respect to the EHV using a Voltage Transformer(VT) or Potential Transformer(PT).  So we refer potential transformer as step-down transformers. Such types of transformers come under the classification of Instrument transformer. Potential Transformers are same as that of a power transformer, but they are used for the protection and measurement of the system voltage. Since its duty is just to measure the magnitude of voltage, its always connected in parallel to the Power lines supplying loads. We usually here the word Potential Transformers while working in a medium voltage switchgear room and substations, power s...