A Calculation Method of Power Cable Emergency Load Time

An emergency load time and power cable technology, applied in the direction of measuring electricity, measuring electrical variables, measuring devices, etc., can solve the problems of power grid dispatching and power repair, etc.

CN103336217BActive Publication Date: 2016-12-28广州骏拓电力科技有限公司 +1
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2016-12-28

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Abstract

The invention discloses a method for calculating power cable emergency loading time. The method for calculating power cable emergency loading time comprises the following steps: a) an AC resistor R, an ambient temperature theta o, a current value I, a conductor temperature value theta c (t), and a conductor temperature initial value theta c (0 +) are calculated when a cable line has a failure; b), a temperature value of the cable conductor after an emergency loading time t=6 tau is calculated; c) a calculating formula of the emergency loading time t is obtained through an expression of the emergency loading time. The method of calculating power cable emergency loading time is advantageous in providing time basis for first-aid repair tasks under the condition of cable line emergencies.
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Description

technical field

[0001] The invention relates to a time calculation technology in an electric power system, in particular to a calculation method for power cable emergency load time. Background technique

[0002] The power system is a whole composed of the production, transmission, distribution and consumption of electric energy. It has a very close relationship with various departments of the national economy and people's daily life. Therefore, it is very important to ensure the normal operation of the power system. However, in the power system, due to accidents or other reasons, a short circuit or a disconnection of one circuit will inevitably occur, and the load will be completely carried by another circuit at this time. In such an emergency situation, whether the emergency load time can be known plays an important role in the success or failure of the emergency repair personnel's emergency repair task. Therefore, it is of great significance to provide a time basis for th...

Examples

Embodiment

[0078] Such as figure 1 As shown, it is the simplified thermal circuit model of the cable system. The physical quantities in the thermal circuit have similar correspondences with those in the circuit. Therefore, the knowledge of the circuit can be used to analyze the thermal performance of the cable. The transient thermal circuit of the cable is similar to A parallel circuit of resistors and capacitors in a circuit. When the cable conductor is supplied with a current I, the heat is conducted to all directions centered on the conductor, and the heat process can be equivalent to the series-parallel thermal circuit of the thermal resistance and heat capacity of each layer of the cable. After equivalent transformation, the final The cable system (including the cable body and the surrounding medium) can be equivalently connected in parallel with a thermal resistance T and a thermal capacitance C.

[0079] Among them, Q is the sum of cable conductor loss, dielectric loss, aluminum ...