What Is The Principle of Rogowski Coil Measurement

The Rogowski Coil is a sensor used to measure alternating current, and its working principle is based on Faraday's law of electromagnetic induction and Ampere's law of loop. When the measured current passes through a Rogowski Coil, an alternating magnetic field is generated around the coil, which induces an AC voltage signal proportional to the rate of change of the current in the coil. ‌

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working principle

The working principle of the Rogowski Coil is mainly based on Faraday's law of electromagnetic induction, which states that the induced electromotive force in a closed circuit is proportional to the rate of change of the magnetic flux passing through the circuit. Specifically, when the alternating current in a conductor changes, a changing magnetic field is generated around it, which induces a voltage signal in the Rogowski Coil. This voltage signal is proportional to the rate of change of the measured current. By integrating this voltage signal through an integrator, an output voltage proportional to the measured current can be obtained.

Characteristics and Applications

Rogowski Coil have the following characteristics:

Magnetic core saturation phenomenon: Due to the use of hollow magnetic cores, Rogowski Coil can avoid magnetic core saturation in high current measurements, making them suitable for high current measurements ranging from several milliamps to several thousand amperes.

Fast response: The hollow design reduces insertion impedance, making signal response faster and suitable for measuring high-frequency currents.

High linearity: The phase difference between the output signal of the Rogowski Coil and the measured current waveform is less than 0.1 °, which can accurately reproduce complex current waveforms, such as transient surge currents.

Flexibility: Rogowski Coil can be flexible and easy to wrap around the tested conductor, suitable for various complex shaped conductors.