Do You Know about Rogowski Coils?

Named after Walter Rogowski, the Rogowski coil is an electrical component designed to measure alternating current and high-speed current pulses.

One common structure features a helical wire coil, with the lead wire from one end passing through the coil center back to the opposite end, leaving both terminals on the same side. This type is known as the reverse-wound Rogowski coil.

Another mainstream design adopts a complete toroidal structure. Its core advantage is avoiding standing wave interference caused by central excitation. The coil can be directly sleeved onto the straight conductor for current detection, and it is manufactured without iron cores.

Factors including winding density, coil diameter and winding stiffness are vital to ensure strong anti-interference ability against external magnetic fields and stable performance regardless of conductor placement.

The induced voltage inside the coil is in direct proportion to the changing rate of current in the tested conductor. Therefore, it normally needs to match an electronic integrator circuit to output signals corresponding to actual current values.

Single-chip microcomputers equipped with built-in analog-to-digital converters are widely applied for signal processing. Additionally, connecting a low-inductance resistor in parallel at the output terminal can realize self-integration without extra circuits, which also effectively enhances the noise resistance of the detection system.