Microchip Technology ARD00330 Fiche De Données
Meter Calibration
© 2011 Microchip Technology Inc.
DS51964A-page 35
2.4.4.1
EQUATIONS FOR CONFIGURATION C1 CALIBRATION – ACTIVE
ENERGY AND ACTIVE POWER
ENERGY AND ACTIVE POWER
Equations 2-13 to 2-17 represent the method for calculating the calibration, and the
correction factors after configuration
correction factors after configuration
C1. The PC calibration software processes these
calculations automatically.
Equations 2-13 to 2-16 apply for calculating the proper output frequency of the CF
output. See Section 2.4.4 “Flow Chart for C1 Configuration – Active Energy,
Active Power Gain” for the meter input conditions.
Equations 2-13 to 2-16 apply for calculating the proper output frequency of the CF
output. See Section 2.4.4 “Flow Chart for C1 Configuration – Active Energy,
Active Power Gain” for the meter input conditions.
EQUATION 2-13:
EQUATION 2-14:
EQUATION 2-15:
EQUATION 2-16:
EQUATION 2-17:
Note: Convert to a 16-bit unsigned integer for compatibility with the energy meter
register and firmware calculations.
Note: Convert to a 16-bit unsigned integer for compatibility with the energy meter
register and firmware calculations.
CF_IMP_S
Meter Constant
3600
-------------------------------------
VBIB
1000
-------------
⋅
=
LINE_CYC_NUM
2
LINE_CYC
=
GAIN
2
32
CF_IMP_S
⋅
Line Freq Samples per Cycle
⋅
--------------------------------------------------------------------------
⎝
⎠
⎜
⎟
⎛
⎞
RAW_ENERGY_ACT
LINE_CYC_NUM 256
⋅
----------------------------------------------------------
⎝
⎠
⎛
⎞
-------------------------------------------------------------------------------- 32768
⋅
=
If GAIN>65535
Then,
GAIN_NUMR_ENERGY_ACT = GAIN / 2
Then,
GAIN_NUMR_ENERGY_ACT = GAIN / 2
GAIN_DENR_ENERGY_ACT = GAIN_DENR_ENERGY_ACT + 1
else,
else,
GAIN_NUMR_ENERGY_ACT = GAIN
GAIN_DENR_ENERGY_ACT = GAIN_DENR_ENERGY_ACT
PLSb = Value from
based on V
B
and I
MAX
values
GAIN_POWER_ACT
VB IB
⋅
PLSb
-------------------
⎝
⎠
⎜
⎟
⎛
⎞
RAW_POWER_ACT
64 LINE_CYC_NUM
⋅
-------------------------------------------------------
⎝
⎠
⎛
⎞
------------------------------------------------------------- 32768
⋅
=