What happens if a Rogowski coil lacks an integrator?

What happens if a Rogowski coil lacks an integrator?

Without an integrator, the signal obtained is di/dt rather than the current itself.

This means:

1. 1. Time-domain measurements (waveforms, RMS, energy) will be completely distorted
2. 2. It can only be used for frequency-domain analysis (e.g., harmonics, high-frequency transients)
3. 3. It cannot be used for conventional applications like energy metering, protection, or monitoring

In other words, without an integrator, a Rogowski coil cannot function as a standard current sensor.

While an integrator is almost always essential, exceptions exist:

1. 1. Devices with built-in integrators

Many modern power measurement chips (ADE7953, ATM90E32AS), energy meters (iEM3555, MD-P1-3-RC-16), and power analyzers (ABB M4M, PW3390), and DSP processors with integrated digital integrators (ADS131E08, TMS320F280049, MCP3910, STM32G4).

2. 2. Specialized applications

Certain motor fault detection or pulse current testing applications focus solely on high-frequency di/dt and can utilize the raw signal directly.

3. 3. “Self-Integration” Scenarios

When the pulse width is significantly shorter than the coil’s time constant, the coil itself exhibits approximate integration characteristics. However, this represents a very niche application.