Investigation of Transients in Induction Current Sensors Based on the Rogovsky Coil

The task of measuring current in different directions of the electric power industry is relevant. Various sensors are used to solve it, including those based on the Rogovsky coil. The fields of application of the Rogovsky coil are as follows: measurement of currents in high-voltage power lines, measurement of the current derivative in DC networks, in control systems of synchronous machines with permanent magnets, measurement of lightning current signals, for monitoring the insulation condition of power cables by measuring partial discharges, for monitoring the rate of current rise in semiconductor power circuits, in circuits protection of IJBT inverters. The article sets and solves the problem of obtaining calculation formulas that determine the relationship between the secondary current and the EMF induced in the secondary winding by the measured primary current. It is taken into account that the shape of the current can be sinusoidal, rectangular or other pulsed character, arbitrary shape. To solve the problem of calculating the transient process, the Duhamel integral formula is used. According to the obtained mathematical expression, taking into account the basic parameters of the sensor, calculations of the secondary current were carried out based on the values of the EMF on the secondary winding, taking into account the inductance of the winding. The curves of the secondary current characterize the change in its instantaneous values and allow an analysis of the signal received from the Rogovsky sensor for use in protection devices and measurements of currents of arbitrary shape.