Winding Resistance Measurement Test of a Power Transformer

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In the winding resistance measurement test of a power transformer, we simply use either the ammeter-voltmeter method or the Kelvin Double Bridge method. Actually, we inject DC current to the winding of the transformer. Additionally, we measure the voltage drop across it. Then we determine the resistance value of the winding by dividing the voltage … Read more

What is an Electrical Fault? A Complete Explanation

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In this article, we will discuss the electrical faults that normally occur in a power system. A short-circuit fault means the connection between two conductive parts of the system through a low-impedance path, where these two parts are at different voltage levels. Due to the low impedance of the path, as well as the voltage … Read more

Protection Zones and Overlapping Zones in Power Systems

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The primary objective of a power system protection scheme is to isolate only the faulty section of the network while keeping the healthy portions in service. This approach improves system reliability and ensures continuity of power supply to consumers. Whenever a fault occurs in any part of a power system, it is desirable to disconnect … Read more

What is Primary and Backup Protection? – Complete Guide

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An electrical power system often suffers from different abnormal conditions. For examples, it may suffer from short circuit faults. The system may go through the overloading conditions. There may be insulation failures. Lightning surges may strike on the system. We call these abnormal conditions together as electrical faults. Any these faults can damage electrical equipment … Read more

Calculation of Short-Circuit Current of Cable (IEC – 60949)

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The thermal withstand capability of a power cable during short-circuit conditions is one of the most important design considerations. During a fault, an extremely high current flows through the conductor and metallic sheath of the cable for a short duration. This fault current produces intense heat. If the temperature exceeds the permissible thermal limit, permanent … Read more