2.2.1.2 Calculating Phase Calibration Factor Using Pulse Calibration Error

Another method to calibrate the phase delay is using the CF pulse error.

Before calibrating the phase delay, set PF to 0.5 Lag (inductive), CAL_PH_Ix (x = A, B, C, N) and CAL_PH_Vx (x = A, B, C) to 0x00000000.

The following formulas are used to calculate the phase calibration constant of phase x:

Example:

After magnitude calibration, pulse measurement of a single channel at PF = 0.5 Lag (50 Hz) shows initial channel accuracy of 99.638%, equivalent to a -0.362% error.

The intermediate quantity (6.6527e-4) provided above, corresponds to a phase shift of +0.12° at 50 Hz, but needs to be normalized to an equivalent linear-phase shift at 60 Hz of +0.144°. All phase shift coefficients used by the metrology DSP must be normalized to equivalent linear-phase shift values at 60 Hz.