Multifactorial automated research of fault location methods based on model of 500 kV overhead power line

Abstract

Fault location is one of the main means of automation of electric power on overhead power lines. Well-timed elimination and organization of maintenance and repair work to put power lines into operation require high accuracy of fault location. Fault location methods based on the parameters of emergency mode using data of electronic (digital or optical) instrument transformers have been developed in Ivanovo State Power Engineering University (ISPU). The use of electronic transformers makes it possible to reduce the instrumental error of fault location due to accurate measurements of electrical quantities during short circuit, including the measurement of the derivative of the primary current. The aim of the study of fault location methods developed by the ISPU team is to evaluate the errors of these methods with a variation of many factors affecting the calculation of fault location in an automated mode using modern modeling tools. A multifactorial automated research of the fault location methods is carried out using a simulation model of an ultra-high voltage network in the Matlab + Simulink software package. One-sided and two-sided fault location methods based on the parameters of emergency mode developed in ISPU are chosen as the studied methods. In the research methodology presented in the article, the values of the factors affecting the measurement of fault location, including the parameters of the network element models, are changed using a program in the MATLAB language with parallel calculations performed on different processor cores. A technique for automated research of fault location methods has been developed including a model of an ultra-high voltage electrical network in Simulink and a simulation model control program in Matlab. More than 100,000 computational experiments have been carried out for each fault location method. According to the study, the influence of transient resistance is excluded, and the influence of the network frequency is practically absent in the two-sided method. The change in the parameters of power transmission lines and equivalent systems is less affected in comparison with the one-sided method. The Monte Carlo method of fault location algorithms has shown that the errors of one-sided method do not meet the requirements of PJSC «FGC UES» standards in less than 20% of cases, and the errors of the two-sided method under the same modeling conditions do not meet the requirements only in 1% of cases. The developed research methodology makes it possible to evaluate the accuracy of fault location methods when changing the set of factors influencing the measurement in an automated mode. The carried-out research of one-sided and two-sided fault location methods based on emergency mode parameters and data of electronic transformers has showed sufficient accuracy on the model of a 500 kV overhead power transmission line with changes in individual factors affecting the measurement of fault location and when randomly setting a set of parameters of the network model.