Two-end distance measuring method of transmission line fault under dynamic condition

Abstract

The invention relates to a two-end distance measuring method of transmission line fault under a dynamic condition, comprising the following steps of: acquiring two-end voltage and current signals through two-end phasor measurement units of the transmission line; then acquiring dynamic positive sequence impedance, admittance, wave impedance and propagation coefficients according to line parameter estimation and a dynamic line parameter method; and finally solving a nonlinear equation related to a fault distance according to the fact that positive sequence voltages derived from two ends to a fault point are equal by applying a Newton iteration method so as to obtain a dynamic distance measuring result of the transmission line fault. The two-end distance measuring method can more effectivelysolve the problem of line parameter and fault distance estimation under the dynamic condition and has accurate and reliable fault distance measuring result.

Description

technical field [0001] The invention relates to a double-terminal ranging method for transmission line faults in a power system. Background technique [0002] With the development of wide-area measurement systems, more and more phasor measurement units have been installed in the power grid, which provides a basis for the double-terminal fault location method based on synchrophasor measurement. The double-terminal ranging method based on the phasor measurement unit can make full use of the fault information, calculate the line parameters online, avoid the line parameters being affected by aging, ambient temperature, humidity and other factors, and can obtain accurate fault location. However, in practical applications, considering the economy, the power system is usually on the edge of stability; on the long-distance transmission line, there are inevitably disturbances, failures and other uncertain factors, resulting in the power grid often being in a dynamic state of oscillat...

AI Technical Summary

Problems solved by technology

However, in practical applications, considering the economy, the power system is usually on the verge of stability; on the long-distance transmission line, there are inevitably disturbances, failures and other uncertain factors, resulting in the power grid often being in a dynamic state of oscillation

The difficulty of double-terminal fault location based on synchronized phasor measurement is that when the amplitude and frequency of the voltage and current signals change rapidly with the system oscillation, the electrical signal described by the original location method cannot have spatial variation characteristics and time The ability to change characteristics will cause large errors in fault location results, making it difficult to achieve accurate fault location and affecting timely troubleshooting

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