Intelligent instrument transformer for control systems of digital substations

The peculiarities of the use in a substation automation system of a digital combined current and voltage instrument transformer of a new type are investigated. The developed transformer has a voltage class of 110 kV and a measurement range of a current from 150–1200 A. The proposed intelligent electronic device is based on an electromagnetic current transformer and a capacitive voltage divider located on the high voltage side. The transmission of the measured instantaneous current and voltage values is carried out over a fiber optic cable. The construction of this transformer makes it possible to develop analogous equipment of information interaction for digital substations with other ranges of currents and voltages based on developed prototype. In existing digital combined instrument transformers, this combination of primary converters is not used. According to the information available, there is no serial production of such products, which indicates the possibility of obtaining a result capable of legal protection and further commercialization.