Modeling of measuring current and voltage transformers in dynamic modes

Most of the works devoted to the study of measuring current and voltage transformers are focused on defining the characteristics of transformers in steady-state conditions to determine whether the transformers satisfy the metrological requirements. Such studies are often carried out using a chain of equivalent circuits or on the basis of field calculation methods. Field calculations methods definitely allow more precisely measuring the leakage field and the distribution of magnetic flux in the magnetic circuit. The study of transformers in dynamic modes is also of much interest. Nonlinearity of the core magnetization of measuring transformers leads to the need to create mathematical models that contain not only a model of the transformer itself, but also the model of circuits connected to it. In particular, of practical interest is the study of the stability of the voltage transformer to ferroresonance phenomena, when the transformer resonates with elements of the primary network connected to it. Thus, it is necessary to develop a mathematical tool allowing to create field models of instrument transformers connected to the primary and secondary circuits allow modeling not only steady modes, but transients ones as well. Problem solving in this formulation became possible after emerging of powerful computers and development of software packages capable to integrate for solving the problems.