PMU measurement-based method for identifying complete parameters of double circuit lines on same tower of short line

Abstract

The invention relates to a PMU measurement-based method for identifying complete parameters of double circuit lines on the same tower of a short line, the PMU measurement-based method comprises the following steps of 1, according to whether a short-circuit same-pole parallel double-circuit line is symmetrical or not, respectively establishing impedance models of short-circuit same-pole parallel double-circuit lines with an in-phase sequence and an out-of-phase sequence; 2, establishing a parameter identification target function of multi-moment PMU measurement based on a least square method; 3,respectively selecting PMU measurements at N moments and N+1 moments, and substituting the PMU measurements into the parameter identification target function established in the step 2 to obtain corresponding parameter identification results alpha N and alpha<N+1>; for the in-phase sequence line, setting an initial value N to be equal to 2; for a non-in-phase sequence line, setting an initial value N to be equal to 4; 4, judging whether alpha N and alpha<N+1> in the step 3 meet the condition that |alpha N-alpha<N+1>| is smaller than or equal to lambda or not, if yes, quitting the cycle, and completing parameter identification; if not, enabling N to be equal to N+1, and executing the step 2 again for recalculation until parameter identification is completed. According to the method, the impedance parameters of the short-circuit same-pole parallel double-circuit line can be accurately and quickly obtained.

Description

technical field [0001] The invention belongs to the technical field of power system parameter identification, and relates to a method for identifying complete parameters of double-circuit lines on the same pole with short lines, in particular a method for identifying complete parameters of double-circuit lines on the same pole with short lines based on PMU measurement. Background technique [0002] With the development of the economy, the requirements for the power system are getting higher and higher, which also makes the power grid more and more complex. As a carrier for transmitting electric energy, transmission lines are an integral part of the power grid. It is of great significance to study the related issues of transmission lines for the analysis and calculation of power systems. Transmission line parameters are the basic data for short-circuit current calculation, relay protection setting, transient stability calculation, power flow calculation and fault location me...

AI Technical Summary

Problems solved by technology

Due to the mutual impedance asymmetry of double-circuit lines paralleled on the same pole without transposition, the estimation error of reactive power of double-circuit lines will greatly exceed the allowable range when estimating its state

At present, there is no relevant research on the analysis of the impedance parameters of the double-circuit line on the same pole without transposition of the short line. Therefore, the present invention studies the impedance parameters of the double-circuit line on the same pole without transposition of the short line. Lay the foundation for realizing the state estimation and accurate power flow calculation of double-circuit lines paralleled on the same pole for short lines

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