Temperature prediction method of high voltage cable joints

Abstract

The invention relates to a temperature prediction method of high voltage cable joints. The method comprises the steps of (1) adopting environmental temperature, environmental humidity, a current ratio of a cover layer and a cable core, and previous temperature values of a cable joint as an inputted training samples, and building a joint temperature prediction model based on a least squares support vector machine; (2) adopting particle swarm optimization to dynamically seek an optimum from a regularization parameter C and a standardized parameter sigma of the least squares support vector machine, and forming a joint temperature prediction model based on the particle swarm optimization and the least squares support vector machine; (3) conducting temperature prediction according to the joint temperature prediction model based on the particle swarm optimization and the least squares support vector machine, the real-time environmental temperature, the environmental humidity, the current ratio of the cover layer and the cable core, and the previous temperature values of the cable joint, and obtaining a predicted value of the high voltage cable temperature. Compared with the existing technology, the temperature prediction method of high voltage cable joints has the advantages of high flexibility, high prediction accuracy, pretty fast training speed and the like.

Description

technical field [0001] The invention relates to the field of high-voltage power cables, in particular to a method for predicting the temperature of a high-voltage cable joint. Background technique [0002] The power cable transmission system can not only beautify the appearance of the city, but also greatly save urban land resources, fully meeting the needs of resource conservation and environmental friendliness. Power cables are widely used in urban power grids, and the demand is growing rapidly. The weak link of the cable system is the cable joint. Field operation experience shows that more than 90% of cable failures occur at the cable joint. Defects inside the cable joint will cause the electric field to concentrate and the local temperature to rise. If it exceeds 137°C, the insulation medium of the power cable will undergo electro-thermal breakdown, which will seriously affect the safe and reliable operation of the power grid. The temperature of the joint can well refl...

AI Technical Summary

Problems solved by technology

Defects inside the cable joint will cause the electric field to concentrate and the local temperature to rise. If it exceeds 137°C, the insulation medium of the power cable will undergo electric-thermal breakdown, which will seriously affect the safe and reliable operation of the power grid.

The temperature of the joint can well reflect the operation status of the cable joint. The existing cable monitoring system can collect real-time data on the temperature of the cable joint, but it cannot predict it.

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