The Reliability of the Measurement and Control of Electrical Voltage Signals in Modern Devices of Relay Protection and Emergency Automation

The paper studies the most typical modes of two-winding voltage transformers. These include the steady-state modes and close to the place of their connection to the power equipment short circuits and breakages of current-carrying elements in it. However, from the position of estimation of the transformation error, it is sufficient to consider the process of including the transformer in the work, which causes the most intense electromagnetic transients in it and is analyzed below. At the same time, the methodical provisions of the method of increasing the accuracy of reproduction of the primary voltage of two-winding voltage measuring transformers were considered, and the results obtained can be further used to further improve other multiphase varieties of these transformers. As a result of the research, the influence of the instrumental error on the value and functionality of the studied scheme of reproduction of primary signals of technical characteristics of analog and digital means, which implement various mathematical operations, is estimated. It is established that the main negative impact is due to the nonlinearity of the mutual inductance Mdif, which leads in the initial stage of the process to a significant increase in the maximum values of the magnetizing current imag and, as a consequence, to increase playback accuracy of u1. As a result of numerical experiments, it is shown that the ideal reproduction of the primary voltage u1, taking into account all the studied negative factors, is possible at a time interval of about 70-80 millisecond from the beginning of the switching process