71M6545 Datasheet, PDF (110/134 Pages) Maxim Integrated Products – Four-Quadrant Metering, Phase Metrology Processors Flash/RAM Size

Data Sheet 71M6545/H
PDS_6545_009
5.4.10 CE Calibration Parameters
Table 77 lists the parameters that are typically entered to effect calibration of meter accuracy.
Table 77: CE Calibration Parameters
CE
Address
0x10
0x11
0x13
0x14
0x16
0x17
0x19
0x12
0x15
0x18
Name
CAL_IA
CAL_VA
CAL_IB
CAL_VB
CAL_IC
CAL_VC
CAL_ID
PHADJ_A
PHADJ_B
PHADJ_C
Defau
lt
16384
16384
16384
16384
16384
16384
16384
0
0
0
Description
These constants control the gain of their respective channels. The
nominal value for each parameter is 2¹⁴ = 16384. The gain of each
channel is directly proportional to its CAL parameter. Thus, if the
gain of a channel is 1% low, CAL should be increased by 1%.
These constants control the CT phase compensation. No
compensation occurs when PHADJ_X = 0. As PHADJ_X is increased,
more compensation (lag) is introduced. The range is ± 2¹⁵ – 1. If it
is desired to delay the current by the angle Φ, the equations are:
PHADJ _ X = 2²⁰
0.029615TANΦ
at 60Hz
0.1714 − 0.0168 ⋅ TANΦ
PHADJ _ X = 2²⁰
0.0206 ⋅ TANΦ
at 50Hz
0.1430 − 0.01226 ⋅ TANΦ
0x12
DLYADJ_A
The shunt delay compensation is obtained using the equation
provided below:
0
( ) DLYADJ
_
X
=
∆_{deg rees}
1 + 0.1∆_degrees
2¹⁴
2π
360
a
2
cos²

2πf
f_s

+
2ab
cos_{}
2πf
f_s
c
sin_{}
2πf
f_s

 ^{+ b}
0x15
DLYADJ_B
where:
0
a = 2A
b = A² +1
0x18
DLYADJ_C
c
=
2 A²
+
4A cos_{}
2π f
f_s

+
2
The table below provides the value of A for each channel:
Channel
Value of A
(decimal)
DLYADJ_A
13840
0
DLYADJ_B
11693
DLYADJ_C
9359
f is the mains frequency.
f_s is the sampling frequency.
Note:
The current sensor inputs are not assigned to the A, B and C phases in a fixed manner. The
assignments of phases A, B and C depends on how the IADC0-1, IADC2-3, IADC4-5, IADC6-7 current
sensing inputs are connected in the meter design. The CE code must be aware of these connections.
See Figure 27 and Figure 28 for typical meter configurations. VADC8, VADC9 and VADC10 are
assigned to voltage phases VA, VB and VC in a fixed manner, respectively.
The CE addresses listed in this table are assigned to phases A, B and C as indicated by their names.
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