Gas Insulated Switchgear (GIS) is a highly compact and efficient electrical equipment used in the transmission and distribution of electricity. One of the crucial tests for ensuring the reliability and safety of GIS is the Secondary Injection Test.
The Secondary Injection Test is a type of functional test that simulates faults in the GIS system and verifies the proper functioning of the protection and control schemes. During the test, a high-current, low-voltage current is injected into the secondary circuit of the protection and control system, while the primary circuit remains operational. The test provides valuable information about the behavior of the protection and control systems during fault conditions and helps to identify any faults or malfunctions in the system.
The test is performed by using specialized test equipment, which also allow for precise measurement of the current and voltage in the secondary circuit. The test is typically performed in two phases: the first phase tests the accuracy of the protection system by measuring the trip time and verifying that the protection system operates correctly, and the second phase tests the control system by verifying that the switchgear operates correctly during normal and fault conditions.
Secondary Injection Test is a crucial step in maintaining the reliability and safety of GIS systems. Planning the test during regular maintenance ensures that the protection and control systems are functioning correctly and helps to identify and address any potential faults before they become critical.