Development of Rogowski Coil Used to Measure the Power Frequency Current and the Lightning Current

When measuring higher current by Rogowski coil with a magnetic core,there will be magnetic saturation phenomenon which leads to poor linearity. Also when measuring lower current by hollow Rogowski coil, there will be little gain and poor accuracy. A broadband active flexible Rogowski coil for detecting the lightning current and power frequency current is developed by flexible Rogowski coil, integral resistors and high input impedance power amplifier. When there is lightning current or power frequency higher current acting to the measuring channel, the waveform and the amplitude of the current will be directly collected by the collection oscilloscope channel. When there is a lower power frequency current signal is applied to the measuring channel, Rogowski coil used in conjunction with external integration circuit can be used to detect weak power frequency current. Before the experiment,the Multisim software is used to simulate Rogowski coil equivalent circuit, based on the simulation results to make and test the coil. After the development of the coil, the error of the measuring coil is tested by 8/20μs lightning current and power frequency current with different amplitudes respectively.Flexible Rogowski coil for measuring lower power frequency current and lightning current would play a certain application value in engineering.