CT PT volt-ampere Analyzer (also known as transformer volt ampere characteristic tester or excitation characteristic tester) is a key equipment used in power systems to test the excitation characteristics of current transformers (CT) and voltage transformers (PT, also known as VT).
Test object and purpose:
CT: The main purpose is to test its excitation characteristics (volt ampere characteristics), used for:
Verify whether the CT meets the accuracy requirements of protection level (such as 5P, 10P) or measurement level (such as 0.2, 0.5).
Calculate the Knee Point Voltage and saturation point of CT.
Evaluate the performance of CT under fault current (saturation characteristics are crucial for protective action).
Diagnose whether there are defects such as inter turn short circuit and iron core aging in CT.
PT/VT: mainly tests its no-load characteristics (excitation characteristics), used for:
Verify the accuracy level of PT (such as 0.2, 0.5).
Check for magnetic saturation or insulation issues with the PT iron core.
Measure no-load current and losses.
Important safety reminder: When conducting CT volt ampere characteristic testing, it is absolutely necessary to ensure that the primary side of the CT is open and no current flows through. In addition to connecting the tester to the secondary side, all external connections (including the grounding wire) must be disconnected. Violating this regulation may result in dangerous high voltage, equipment damage, and even personal injury. During PT testing, it is also necessary to ensure the safety isolation of the primary side. Strict adherence to safety regulations is required during operation.