When it comes to ensuring the accuracy and reliability of a 33kV Voltage Transformer (VT), testing is an essential process. VT testing involves various procedures, including checking the turns ratio, magnetization curve, and insulation resistance.
VT testing included:
Insulation Resistance (IR) & Winding Resistance Measurement
Polarity & Ratio Verification (33kV / 110V)
Magnetization & Burden Test
Secondary Circuit Continuity Check
Protection & Metering Functionality
One crucial test that needs to be conducted is the burden test. It is performed to verify the accuracy of the VT by simulating the actual load that the VT will experience in the field. This test involves applying a specific burden (usually expressed in volt-amperes or VA) to the secondary winding of the VT while monitoring the output voltage. The test aims to determine if the VT can accurately step down the voltage across the specified range of loads.
During the burden test, it is important to consider factors such as the accuracy class of the VT, the range of loads it is expected to handle, and the required accuracy of the voltage measurement. The results of the burden test will help determine if the VT meets the required accuracy specifications and if any adjustments or corrections are needed.