Combined Digital Current and Voltage Transformer for Medium Voltage Networks

This article presents the process of developing digital measuring transformers for the medium voltage class (6 35 kV) and an analysis of the existing problems of regulatory documentation related to this area. The article contains information about the hardware principles of the proposed solution, in addition, the metrological requirements for this class of devices are presented. The structure of interaction between measuring transformers and other equipment at a digital substation is described separately from the point of view of the IEC 61850 standard. The proposed verification method for the device under development is presented in detail with the calculation of the errors of each circuit, the results of real testing of a prototype of a combined digital current and voltage transformer are shown. This article presents a set of equipment with a description of their characteristics for setting up a scheme of the verification method of the developed combined digital current and voltage transformer.