Test method without disconnection of capacitor voltage transformer

Abstract

The invention discloses a test method without disconnection of a capacitor voltage transformer. The capacitor voltage transformer comprises a capacitor C11, a capacitor C12, a capacitor C2, a reactor L and an intermediate transformer XT, wherein the primary capacitors (C11 and C12) and the voltage-dividing capacitor C2 constitute a capacity divider; a point A is arranged between C11 and C12, a point B is arranged between C12 and C2, a point delta is arranged on the other end of the capacitor C2; when C12 is tested, the reverse wiring method and the high voltage shielding method are used for measurement, namely the point A is connected with the high-voltage end, one end of C11 is earthed, the measuring voltage is 2kV and the point delta and a point X at the tail end of the intermediate transformer XT are connected with the shielding end; and when C12 and C2 are tested, the self-excitation method is used for measurement, namely one end of C11 is earthed, the secondary winding ax of the intermediate transformer XT is used to apply a voltage and the intermediate transformer XT is used to transform the voltage and provide a voltage. By using the test method of the invention, the testing sequences are greatly reduced, the operation procedure is simple, the test data are accurate and the reading error is small.

Description

technical field [0001] The present invention relates to a test method for a capacitive voltage transformer, in particular to a test method for a capacitive voltage transformer without removing the head. Background technique [0002] Capacitive voltage transformer (referred to as CVT) is a very important high-voltage power transmission and transformation equipment. The voltage transformers currently used in my country's 110kV and above power systems mainly include capacitive voltage transformers and electromagnetic voltage transformers. Because CVT has the advantages of high dielectric strength, can reduce the steepness of lightning shock wave head, does not occur ferromagnetic resonance with the system, is low in cost, and can also be used as a coupling capacitor for power line carrier communication, etc. At the same time, due to the progress of related materials and manufacturing technology, Therefore, the application of CVT has developed rapidly since the middle of the 20t...

AI Technical Summary

Problems solved by technology

CVT is generally suitable for voltage levels of 110kV and above. However, due to the limitations of various factors such as design level, manufacturing experience, process level and raw materials, if a fault occurs after putting into operation, it will affect the safe operation of the power grid, which is affected by the operating environment and voltage level. Especially for equipment with a voltage level of 220kV and above, it is tall and has heavy lead wires, which makes the workload and difficulty of disassembling the electrical test large, and the power outage time is long. In addition, all surrounding equipment is charged, and forced work will seriously threaten Equipment and personnel safety, which requires testing the CVT before use

In the existing test method for capacitive voltage transformers without dismantling the head, when the harmonic interference of the test power supply or the external electric field interference is strong, the bridge is difficult to balance, and the reading error is large, and the measures to eliminate the interference make the test steps numerous. It is complicated and influenced by human factors. Therefore, how to find a new test method that does not need to disassemble the capacitive voltage transformer during the test is a top priority.

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