Method and device for calculating conductor temperature of cable

Abstract

The invention discloses a method for calculating the conductor temperature of a cable. The method comprises the following steps: calculating a relation expression between a calculated value of the conductor temperature of the cable in a steady state and a heat-conductivity coefficient of a structural material of each layer of the cable by using a thermal-circuit method; calculating a functional relation between the heat-conductivity coefficient of the structural material of each layer of the cable and a corresponding sensitivity by using a sensitivity principle, and calculating the value of a sensitivity corresponding to the heat-conductivity coefficient of the structural material of each layer of the cable according to the functional relation; and adjusting the value of a selected heat-conductivity coefficient according to the value of the sensitivity, then calculating the conductor temperature of the cable according to the adjusted value of the heat-conductivity coefficient. The invention also provides a device for calculating the conductor temperature of the cable. By using the technology of the invention, the conductor temperature can be calculated accurately and the current-carrying capacity of the cable can be assessed accurately; and the calculated value of the conductor temperature of the cable is significantly improved on the basis of a calculated value stipulated in IEC (international electrotechnical commission) standards, thereby avoiding the occurrence of a problem that a result of the conductor temperature of the cable, calculated according to the IEC standards, has an excessive margin and a large error; and the method and device disclosed by the invention provide references for the real-time monitoring of the cable and the improvement of transmission capacity and operation of the cable.

Description

technical field [0001] The invention relates to a conductor temperature calculation method, in particular to a cable conductor temperature calculation method and device. Background technique [0002] With the rapid development of my country's economy, the modernization process of urban construction is accelerating. In order to meet the rapidly growing power supply demand of users, the number of medium and high voltage power cable lines in urban power grids is increasing. However, urban control and dense lines make it extremely difficult and stressful to add new power cables. Therefore, it is of great significance to safely increase the transmission capacity of cables on existing power lines. [0003] Conductor temperature change is one of the most direct characteristics of cable current change. Once the cable conductor temperature and related boundary conditions are determined, the current carrying capacity of the cable can be determined. At present, there are still technic...

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Problems solved by technology

[0006] The purpose of the present invention is to provide a method and device for calculating the temperature of cable conductors, which solves the problem of excessive margin and large error in the results of calculating the temperature of cable conductors using IEC standards

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