This guide provides a comprehensive overview of how to use a relay tester to test and troubleshoot the differential protection system of a GE transformer. It covers the testing principle, calculation methods, wiring guidance, and result analysis methods, all of which are essential for ensuring the proper functioning of the protection system.

Testing Principle: The relay tester is designed to simulate various fault conditions in the transformer protection system to verify that it responds correctly. The differential protection system of a transformer works by comparing the currents in the primary and secondary windings. The relay tester can simulate this condition and ensure that the protection system responds correctly.

Calculation Methods: To test the differential protection system, we need to calculate the expected values of the primary and secondary currents. The formula is as follows:

I1 = (Ip + Is) / 2 I2 = (Ip - Is) / 2

Where I1 is the expected current in the primary winding, I2 is the expected current in the secondary winding, Ip is the current in the primary winding, and Is is the current in the secondary winding.

Wiring Guidance: The relay tester needs to be connected to the protection system's inputs to test the differential protection system. The wiring diagram is as follows:

1. Connect the relay tester to the primary winding of the transformer.
2. Connect the relay tester to the secondary winding of the transformer.
3. Connect the relay tester to the differential protection system's inputs.

Result Analysis Methods: After the test is complete, we need to analyze the results to ensure that the protection system is working correctly. The analysis methods are as follows:

1. Compare the expected values of the primary and secondary currents with the actual values measured by the relay tester.
2. Verify that the differential protection system responds correctly to the simulated fault conditions.
3. If there are any discrepancies, troubleshoot the system and make any necessary adjustments.

Example: Let's say we need to test a GE-manufactured transformer protection system. We can use a relay tester for testing. Here are the testing steps:

1. Understand the working principle and parameter settings of the transformer protection system.
2. Connect the relay tester to one of the transformer protection system's inputs.
3. Test the transformer protection system's performance by simulating various fault conditions.
4. Record the test results and compare them with the expected results.
5. Troubleshoot the system and make any necessary adjustments.

Conclusion: The relay tester is an effective tool for testing and troubleshooting the differential protection system of a transformer. By following the testing principle, calculation methods, wiring guidance, and result analysis methods outlined in this guide, we can ensure that the protection system is working correctly and prevent any potential faults in the transformer.