High-voltage and high-current composite thermally stable test method and device for high-voltage casing pipe

Abstract

The invention discloses a high-voltage and high-current composite thermally stable test method and a high-voltage and high-current composite thermally stable test device for a high-voltage casing pipe. The device comprises a high voltage generator, a high current generator, a simulating transformer tank and an insulating oil heating device which is arranged in the tank, wherein the high-voltage casing pipe to be tested is arranged on the simulating transformer tank; and the insulating oil heating device is an electric heating device which uses an externally connected power supply to heat the insulating oil in the tank to the temperature of more than or equal to 90 DEG C. The device is characterized in that the current of the high voltage generator is less than or equal to 10A, the output voltage of the high voltage generator is between 1,000kV and 2,400kV according to a test requirement, a high voltage outputting terminal of the high voltage generator is connected in parallel with two conducting rods outside the tank of the high-voltage casing pipe, and a low voltage outputting terminal of the high voltage generator is grounded; and the output voltage of the high current generator is less than or equal to 2kV, the output voltage of the high current generator is between 200A and 10,000A according to the test requirement, and an output end of the high current generator is respectively connected with two conducting rods at one end of the tank of the high-voltage casing pipe. By the method and the device, experiments which can be finished only by a large-capacity power supply in the prior art can be realized, and the test cost is greatly saved.

Description

technical field [0001] The invention relates to a thermal stability test method and device for a high-voltage bushing, specifically a composite thermal stability test method and device for simultaneously loading high voltage and high current in the high-voltage bushing thermal stability test, which belongs to the high-voltage electrical appliance test technology field. Background technique [0002] With the increase of power grid capacity, the primary current amplitude of ultra-high voltage and high voltage power distribution and transformation equipment has also increased significantly. The rated current of current transformers used in 220kV to 500kV power grids has reached 3000A to 5000A, and the rated current of large-capacity generator sets or transformers The current is close to 30kA. High-voltage bushings are needed between these equipment and lines as transitional high-voltage and high-current devices. Because the operating environment and location of high-voltage bu...

AI Technical Summary

Problems solved by technology

However, the disadvantage of this method is that the rated load current is not loaded through the high-voltage bushing at the same time, which is inconsistent with the actual operating conditions of the high-voltage bushing.

The well-known bushing thermal stability test method lacks the influence factor of current heating, and the distribution of the thermal field is loose

This has also caused according to the currently known test, after the high-voltage bushing test is qualified, accidents often occur in operation

[0004] If the conventional method of simultaneously applying high voltage and high current to the test product by the test transformer is used, the power supply capacity is required to be huge and cause loss and waste. Power capacity S = 200kV × 3500A = 700MVA

What is disclosed in the Chinese invention patent "Live Test Method for UHV Equipment" (Application No.: 200810048950.6) is to establish a large-capacity live test equivalent hanging net that can simulate the actual high-voltage and high-current operation conditions. Carry out live assessment to verify the safety and reliability of its design, manufacture and process. The test cost of this method is huge; Publicly, the method of sealing and high-temperature testing of the fuel tank can heat the bushing and increase the current, but it cannot load high voltage

This is because the technical difficulties involved in high current and high voltage are different, and it is difficult to take care of both in one set of equipment.

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