Distributed automated control and protection system for power lines with any degree of longitudinal compensation

Abstract

With longitudinal compensation of the reactance of the line, the problem of its protection against overcurrents arises from the point of view of relay protection. The problem is relevant with a greater degree of compensation. When compensating more than 50% of the reactance of the line, the protection of the power transmission line becomes practically impossible due to the failure or false operation of all existing types and forms of protection [1, 2]. Therefore, at present, the compensation of the line reactance is, as a rule, no more than 50% [3, 4], which does not allow the full potential of the line in terms of its transmission capacity to be revealed. The purpose of this study was to develop and test a new relay protection algorithm to be able to solve the above problem. The studies were carried out using modeling techniques in the PS CAD package, where a power transmission line with longitudinal compensation and an algorithm to protect it from internal damage were built. When carrying out the research, the work was carried out on the protection algorithm of the power transmission line with longitudinal compensation in the static mode without transferring electricity between substations and without the transmission mode along the active power line in both directions. It is shown that in order to determine the location of the damage, it is possible to use the criterion of the angle of the active component of the short-circuit current, which depends exclusively on the voltage angle and does not depend on the reactive parameters of the electrical network. The simulation result showed correct operation in all investigated modes. The algorithm described in the article showed quite satisfactory results, which makes it possible to protect the power transmission line with any degree of longitudinal compensation.