Method for measuring line parameter through induced electricity

Abstract

The invention provides a method for measuring a line parameter through induced electricity, which is characterized by comprising the following steps: (1) setting one end of a line into an open-line state, maintaining the other end to a ground state, selecting an internal power reference phase, and utilizing a voltage divider and a waveform measuring and recording device to measure a three-phase open-line induced voltage of a dead line in a common tower or parallel multi-circuit line on the premise of not applying a signal source outwards; (2) maintaining both ends of the line to the ground state, selecting the internal power reference phase, and utilizing a current transducer and the waveform measuring and recording device to measure a three-phase short-circuit induced current of the dead line; and (3) decomposing the induced voltage and the induced current by the processing of software and hardware such as filtering, nuclear phase, sequence component decomposition and the like to obtain zero-sequence and positive-sequence voltages and zero-sequence and positive-sequence currents so as to obtain zero-sequence impedance and positive-sequence impedance of the dead line. The method adopts a signal measuring and recording device to measure the induced voltage and the induced current on the dead line on the premise of not applying power outwards, and utilizes a component decomposition method to solve the line parameter so as to prevent the line parameter from being impacted by the induced electricity.

Description

technical field [0001] The invention relates to a method for solving line parameters by using the sequence component decomposition method by measuring the induced voltage and current amplitude and phase of the power failure line without external power supply by using the induced electricity of the power failure line itself, belonging to high voltage Power transmission and transformation technology field. Background technique [0002] The power frequency parameters of transmission lines, such as positive sequence parameters and zero sequence parameters, are important parameters for power system power flow calculation, relay protection setting calculation and system operation mode selection. Since transmission lines are affected by factors such as changes in soil resistivity, changes in line direction and geographical location, and climate and environment after they are put into operation, it is very difficult to accurately calculate line parameters. [0003] As the route cor...

AI Technical Summary

Problems solved by technology

Due to the strong electromagnetic coupling between multi-circuit lines erected on the same tower or side by side, there is a strong electromagnetic interference voltage on the line under test due to the induced electricity of the running line. Conventional measurement methods such as frequency shift test method, test line parameters on site , the test accuracy is poor, and when the induction current of the power failure line is very high, the instrument often cannot work normally

Therefore, when the interference between multiple circuits or parallel lines on the same tower is strong, it is difficult to guarantee the measurement accuracy of line parameters by the frequency shift line test method

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