Can Protection CT be used as Metering CT & Vice Versa?

Protection Current Transformer (CT) and Metering CT are two different types of CT as per their requirement and hence design. Therefore, Protection class CT should not be used as Metering CT. Similarly, a Metering Current Transformer should not be used for protection purpose. Let the discuss the reason behind this. Why can’t we use Protection … Read more

Current Transformer – Construction, Phasor and Errors

Current Transformer is an instrument transformer which steps down high value of current to a low value of current suitable for measurement devices. It is widely used in power system for measurement and protection purpose. We cannot think of power generation, transmission or distribution without using Current Transformer. Construction of Current Transformer (CT): There are … Read more

Knee Point Voltage of Current Transformer

According IEC, Knee Point Voltage of a Current Transformer is defined as the voltage at which 10 % increase in voltage of CT secondary results in 50 % increase in secondary current. If you carefully read the definition, you will notice that it is something related to saturation of Current Transformer CT. Never mind, I will … Read more