Working Principles of Winding Resistance Tester
The winding resistance tester is one of the top performance testers specifically made for large motor and power transformer applications. Basically, the winding resistance testing is a vital part of the manufacturing quality assurance program and power transformer maintenance. Usually, the large motors and transformers are subjected to overloading, vibrations and environments with high temperature variations. This winding resistance tester can be used to perform measurements and assure that the connections are made accurately without any shorts or opens. However, winding resistance tester is highly effective to use in finding the tap changer abnormalities. The tap changer of power transformer is especially the most critical element of a power system.
The purpose of winding resistance tester can inject a direct current via the windings and also measures the drop of voltage. One of the most challenging tasks in the winding resistance measurement is that voltage across the inductor can be calculated by V= L (di/dt). Here, L denotes the inductance of winding and (di/dt) denotes the rate of change of current. If there is a small change in the power supply, then it might be caused by poor regulation or ripple. This will make it impossible to measure the direct current resistance.
The major applications of winding resistance tester are given below:
1. Instrument transformers
2. Rotating machines
3. Power transformers
4. Voltage regulators
The winding resistance testing can always perform measurements on very big transformers for highly filtered and regulated current output.