Power loss calculation method for power cable sheath

Abstract

The invention discloses a power loss calculation method for a power cable sheath. An equivalent admittance matrix of a cable is derived according to basic parameters of the cable and the structure of the cable; the current of a cable sending end is calculated and determined according to the equivalent admittance matrix of the cable and boundary conditions of a cable system; the sheath current of each point of each section along the cable is determined according to the current of the cable sending end, and therefore the loss of the cable sheath is determined. Compared with the prior art, the power loss calculation method is short in consumed time and high in precision, the precise distribution condition of voltage and current along the cable can be calculated, the sheath loss of each section of the cable is determined, and a theoretical basis is provided for subsequent cable loss reducing strategies.

Description

technical field [0001] The invention belongs to the technical field of electric power transmission, and in particular relates to a method for calculating power loss of a power cable sheath. Background technique [0002] The power cable transmission method has developed rapidly in recent years, and more and more underground transmission systems are used in the expansion of urban power grids. There are three main reasons: First, the growing environmental problems limit the use of overhead lines in cities. Second, in the field of marine power transmission, submarine cables have incomparable advantages over overhead lines; third, innovations in cable manufacturing and operation technology make insulated cables more competitive. [0003] In single-core cables, the cable sheath protects the single-core conductor from moisture and mechanical damage; in addition, the cable sheath shields electrostatic fields and serves as a return circuit for fault currents and capacitive charging c...

AI Technical Summary

Problems solved by technology

The more effective method for systematically studying sheath loss is the full-phase model method, but the traditional full-phase model method has the following two problems: 1) It is necessary to establish a node voltage equation in each subdivision, if the model is to be guaranteed Accuracy, the overall voltage equation may be as high as tens of thousands of orders, and the solution is very time-consuming and laborious; 2) When the traditional method obtains the transmission matrix of the coupled line, it needs to solve the eigenvalues ​​and eigenvectors of the complex matrix, which is also a very time-consuming link.

Generally speaking, traditional sheath loss calculation methods are inefficient and time-consuming for complex cable systems

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