Definition of Metering Accuracy for Rogowski Coil

[123MB]

Hi All

This seems like quite a basic question but what is the definition of 'measuring error' for a rogowski coil power metering system

For example, systems are typically stated as having 1% rated accuracy for the rogowski coil and the measuring relay.

Is this 1% of the measured value, or of the maximum measurement range of the device

Likewise for a power meter which has Class 0.5 accuracy, it is accurate to 0.5% - is this percentage of the measured value, or the maximum range?

 

[scottf]

My opinion is that type Rogowski coils would not be suitable for metering and certainly not revenue metering.

The error defined for Rogowski coils is normally referring to the ratio error only. Phase angle error on Rogowski coils can be quite high...normally defined in degrees...0.5 to 1.0 degrees is what I've seen in the past.

Conventional current transformers have metering CLASSES of 0.2 or 0.5 (sounds like you're in IEC world) or 0.15/0.3 (for ANSI/IEEE). These classes define both the ratio error and the phase angle error and the PA error is defined in minutes vs degrees.

 

[123MB]

Appreciate that sir

Do you have a view on whether the percentages relate to full scale or measured value?

 

[scottf]

The accuracy rating would be measured value.