On-line measuring device and method for electrical parameters of power transmission and distribution line

Abstract

The invention discloses an on-line measuring device and an on-line measuring method for electrical parameters of a power transmission and distribution line. The on-line measuring device for the electrical parameters of the power transmission and distribution line comprises a plurality of measuring unit; each measuring unit communicates with a main station system through a data concentrator. Time synchronization is performed among the measuring units through a clock synchronization unit. The measuring units collect synchronous phasor data of corresponding measurement points under the same time point by each given time interval through one CT (i.e., current transformer) and one PT (i.e., potential transformer). The measuring units are also connected with a measuring current sensor and a protective current sensor through a measuring range switching circuit. When the power transmission and distribution line is in fault, a corresponding waveform can still be recorded by utilizing the measuring range switching circuit. The measuring units send the collected data to the main station system through the data concentrator. The on-line measuring device for the electrical parameters of the power transmission and distribution line utilizes the synchronous phasor measuring terminal DPMU that is specified to the power distribution system for improving the real-time performance and the accuracy of the power distribution network data acquisition.

Description

Technical field [0001] The present invention relates to the technical field of power system operation, in particular to an online measurement device and method for electrical parameters of power transmission and distribution lines. Background technique [0002] Power system operation and analysts' grasp of power grid characteristics rely on real-time monitoring and analysis based on power grid models. Accurate grid parameters are the basis for forming an accurate grid model for power system calculations. Therefore, improving the accuracy and reliability of power grid parameters is of great significance to the safe and stable operation of super large power grids. [0003] In view of the different specific conditions of each line, and transmission lines, especially 220kV and above voltage grade lines, almost have running lines parallel to it or erected on the same pole, which brings great interference and difficulties to the parameter measurement of transmission lines. Due to the l...

AI Technical Summary

Problems solved by technology

[0004] In the actual measurement of line parameters, due to the influence of factors such as too long lines, insufficient capacity of measuring devices, or mutual inductance of parallel lines, the measured parameters obtained by the line power failure measurement method often differ greatly from the theoretical values, so the accuracy is questioned

In addition, the current line parameter measurement device requires line power failure during the measurement process. Power failure of 110kV and above lines will weaken the grid structure. Therefore, the power grid operation management department needs a more accurate and online line measurement device

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