Ultra-High-Speed Transmission Line Differential Protection using an Error Index of Bergeron Equation

Abstract

The Ultra-high-speed and simplicity of protection schemes have been a subject of study in recent years. Therefore this document develops a differential protection method in transmission lines using voltage and current traveling waves signals, where the transmission lines are modeled through distributed parameters and expressed by telegraph's equations which is solved using Bergeron's equations, these equations depend on instantaneous signals and historical components. Using an error index that compares the voltage and current signals from the line ends, the fault is detected. Furthermore, signals with synchronized measurements with the same time stamp are considered. This method uses simple criteria and fast operation time, because it uses algebraic operations and a time window between 1 and 2 ms. A power system is modeled on ATPDraw and many faults cases are simulated; several conditions such as inception angle from voltage signal, fault resistance, fault distance and internal/external faults are considered. In the case of three-phase systems, the use of Clarke's modal decomposition is proposed. Good results in the operation are obtained and comparing with traditional algorithms this method presents low operating times.