3.1.33 Per-Phase Active Power Offset Register

This value indicates the per-phase active power offset, POWER_OFFSET_P_x: where x = [A, B, C]. The units of POWER_OFFSET_P_x is [W samp-scaled].

For a fixed voltage, this offset may be computed by applying voltage phase(s), setting zero current(s) and reading the phase’s active power accumulator, P_x. Averaging over many readings or a longer integration period may provide a more statistically accurate estimate.

Where, N = Number of samples in integration period.

Name: POWER_OFFSET_P_x
Property: RW, Format sQ-9.40 (same format as the lsb 32-bits of 64-bit P_x accumulators)

Bit 3130292827262524 
 POWER_OFFSET_P_x[31:24] 
Access RWRWRWRWRWRWRWRW 
Reset 00000000 
Bit 2322212019181716 
 POWER_OFFSET_P_x[23:16] 
Access RWRWRWRWRWRWRWRW 
Reset 00000000 
Bit 15141312111098 
 POWER_OFFSET_P_x[15:8] 
Access RWRWRWRWRWRWRWRW 
Reset 00000000 
Bit 76543210 
 POWER_OFFSET_P_x[7:0] 
Access RWRWRWRWRWRWRWRW 
Reset 00000000 

Bits 31:0 – POWER_OFFSET_P_x[31:0] Per-Phase Active Power Offset Register

POWER_OFFSET_P is stored in sQ1.30 format, and its value is subtracted each sample at a 4 kHz rate.