Анализ работы дистанционной защиты от замыканий на землю

Наиболее распространенной защитой линий электропередач от всех видов повреждений является дистанционная защита. Однако, при кз на землю через большое переходное сопротивление работа дистанционных измерительных органов не всегда эффективна. Разработанный алгоритм синтезирован по уточненной модели защищаемого объекта в режиме кз на землю. Получены оценки эффективности работы нового и классического алгоритмов дистанционной защиты линии в различных режимах кз на землю и при различных величинах переходного сопротивления в месте коротких замыканий. Результаты анализа показали, что новый алгоритм эффективнее классического

The Effectiveness Increasing for Distance Protection

The developed earth fault distance measuring unit (DMU) algorithms touch on the subject of the effectiveness increase for distance relay operation. The impedance-measuring problem is considered as the optimization problem. It is proposed the control bus voltage balance equations to use as the objective function of optimization. The balance is determined as difference between the measured bus voltage and the bus voltage, which is calculated by monitoring currents and network parameters. The specific DMU algorithms, which are based on Newton optimization methods, are presented. It is analyzed by CAPE program of Latvenergo network model. The earth faults conditions at 330kV HVTL for single and tapped line configuration were performed. It is shown, that the developed DMU algorithms are more effective then classic

Analysis of Quality for the Slightly Turbulent Regime during the Random Oscilations in the System

The development of power systems and their associations creates the increasing variety of structures and conditions of those united power systems. Under these conditions it is necessary simultaneously to achieve coordination of the automatic excitation control (AEC) gains at many stations and to provide the high quality of the transient processes. Practically this becomes possible only upon transfer from the analog regulator to digital, fulfiled on the microprocessor base. In this case the new principles of adaptive regulation in highest degree corresponding to the management tasks in the modern united power systems may be realized. By study of transient processes is understood the estimation of their quality and system stability during different disturbances of its regime. The providing of the best quality of the slightly turbulent regimes due to the selection of the parameters of the automatic regulation devices and first of all, AEC of the generators, is the task of the oscillatory stability analysis

The Distance Measuring Units Algorithm Synthesis on the Basis of the Earth Fault Specified Model

The distance protection is the most common protection of the electric power transmission lines. However, the distance measuring units operation during the earth fault through the fault resistance is not always effective. This paper presents the new earth fault distance protection measuring units algorithm, which is based on the precise model of the protective object during the earth fault. It is obtained the estimations of the operation effectiveness of new and classical algorithms for the distance protection in the different earth fault regimes with different values of fault resistance

The Effective Earth Faults Distance Protection Algorithm for Tapped Lines

One of the main problems with distance protection of tapped lines is related to zero sequence infeed from an earthed tap-transformer. For the solution of this problem the distance measuring units algorithms for the tapped lines are developed. The new earth-faults distance protection algorithms are based on the use of numerical optimization methods and the objective function adaptation of to the network configurations. The estimations of new and classical algorithms operation in different earth fault conditions at the end of first protective zone are obtained. It is shown that the effectiveness of the developed earth-fault distance protection algorithms operation during different fault conditions on the tapped lines are higher then effectiveness of the classic algorithms