Phase voltage measurement method of single-phase overhead transmission line

Abstract

The invention provides a single-phase overhead power transmission line phase voltage measurement method. The line and the ground are seen as a large capacitor to perform voltage division measurement by using the principle of space capacitance voltage division, and the air acts as the insulation medium. A lumped parameter equivalent circuit is established and a line voltage measurement model is constructed according to the distributed capacitance of the lead to the ground and the distributed capacitance between the sensor and the lead, and the analysis indicates that the height change of the line has no influence on measurement in actual application. According to the phase voltage measurement method, the stable voltage division ratio can be acquired, noncontact power transmission line phase voltage measurement can be realized, and the method is suitable for the requirements of a distribution network distributed device and better than the present voltage measurement scheme.

Description

technical field [0001] The invention relates to a method for measuring the phase voltage of a single-phase overhead transmission line applied in an overhead line distributed voltage sensor. Background technique [0002] With the continuous development of my country's electric power industry, building a strong smart grid has become the future development direction. At present, my country's distribution network has a large number of lines, wide areas and long lines, and the environment is complex and the failure rate is high. The development of low-cost distributed monitoring devices can realize real-time online monitoring and fault location of the distribution network operation status. Operation is of great significance. [0003] Distributed and accurate measurement of phase voltage of overhead lines in distribution network is a difficult point. Currently widely used voltage sensors mainly include electromagnetic (PT), capacitive (CVT) voltage transformers, optical voltage s...

AI Technical Summary

Problems solved by technology

Traditional PTs are affected by factors such as small capacity, high cost, complex insulation structure, ferromagnetic resonance phenomenon, and leakage inductance distributed capacitance, which gradually do not meet the needs of today's power grids.

CVT is mainly used in power grids above 330kV. It is bulky, expensive, difficult to install, and cannot meet the requirements of low-cost distributed devices.

Images