Load cycle test insulating temperature gradient control method and system for high-voltage direct-current cables

Abstract

The invention relates to a load cycle test insulating temperature gradient control method and system for XLPE insulated high-voltage direct-current cables. A wire core current and surrounding medium temperature of the cable in an analog loop are controlled, so cable wire core temperature and insulating shielding layer temperature reach set values; the analog loop serves as a reference, a wire core current and surrounding medium temperature of the cable in a test loop are regulated to the identical to the wire core current and the surrounding medium temperature of the cable in the analog loop. At the moment, it is considered that cable wire core temperature and insulating shielding layer temperature in the test loop are identical to those in the analog loop and also reach the preset values. By means of the method, the cable wire core temperature and the insulating shielding layer temperature of the full-size XLPE insulated high-voltage direct-current cables in a load cycle test period can be controlled effectively, so a stable and controllable temperature gradient is formed for XLPE insulation, and the research requirement for insulation performance of the XLPE insulated high-voltage direct-current cables is met.

Description

technical field [0001] The invention relates to a method for controlling the insulation temperature gradient of a high-voltage direct current cable load cycle test. The present invention also relates to an insulation temperature gradient control system for high-voltage direct current cable duty cycle testing dedicated to the method. Background technique [0002] The XLPE insulated HVDC cable used in HVDC transmission lines has a series of advantages such as small size, large transmission capacity, high insulation level, low maintenance cost, and small environmental impact. applied in engineering. However, the systematic research on the long-term operation and aging process of this high-voltage DC cable is not perfect at present. [0003] The temperature gradient of the main insulation of the HVDC cable has a direct impact on its insulation state and service life, especially for XLPE insulated HVDC cables, under DC voltage, (1) the electric field distribution in the XLPE in...

AI Technical Summary

Problems solved by technology

[0004] At present, the insulation temperature gradient control method for high-voltage DC cable load cycle test only controls the temperature of the cable core, and there is no method for accurately controlling the temperature of the outer surface of the cable, which cannot form a stable and controllable temperature gradient on the XLPE insulation.

Images