Modeling and Analysis of the Functioning of Digital Relay Protection with Remote Current Measuring Transducers

Current protectors are most commonly used to protect electrical installations from short circuit (s/c) when the controlled parameter is exceeded. [1]–[5]. To obtain information about the current in the primary high-voltage circuit, the protection data is usually connected to electromagnetic current transformers (CT), which, first of all, convert the primary current to the secondary current values allowed by the operating conditions of the protection, and secondly, provide galvanic isolation of protection circuits from high-voltage circuits. In this regard, the dimensions and cost of CT insulation increase with the nominal voltage of the electrical installation for which they are used. [6]. In addition, CTs are also characterized by other disadvantages, the most significant of which in terms of considering issues of relay protection (RP) is the possibility of saturation and increase in the primary current conversion error to values at which a significant slowdown of current and distance protections or false protection action of differential protections. [7]–[9].