71M6511 Datasheet, PDF (72/95 Pages) Teridian Semiconductor Corporation – Single-Phase Energy Meter IC

71M6511/71M6511H
Single-Phase Energy Meter IC
DATA SHEET
AUGUST 2007
Current Shunt Variables
Input variables: IA_SHUNT and IB_SHUNT can configure the current inputs to accept shunt resistor sensors. In this case the
CE provides an additional gain of 8 to the current inputs. This will enable the pulse rate to change by 8 times. In order to
maintain a normal pulse rate WRATE may have to be decreased by 8 times. Whenever IA_SHUNT or IB_SHUNT are set to 1
or a positive number, In_8 is assigned a value of 8 in the equation for Kh.
CE
Address
2A
2B
2C
Name
IA_SHUNT
IB_SHUNT
RESERVED
Default
-1
-1
Description
When +1, these variables increase the respective current gain by 8. The
gain factor controlled by In_SHUNT is referred to as In_8 throughout this
document. Allowed values are 1 or –1. For example, if IB_SHUNT=-1, IB_8
= 1, if IB_SHUNT = 1, IB_8 = 8.
IA_SHUNT corresponds to IA_8, IB_SHUNT corresponds to IB_8.
CE Calibration Parameters
The table below lists the parameters that are typically entered to affect calibration of meter accuracy.
CE
Address
8
9
A
B
C
D
E
Name
CAL_IA
CAL_VA
CAL_IB
RESERVED
RESERVED
RESERVED
PHADJ_A
F
PHADJ_B
10
RESERVED
Default
16384
16384
16384
Description
These constants control the gain of their respective channels. The nominal
value for each parameters is 2¹⁴ = 16384. The gain of each channel is directly
proportional to its CAL parameter. Thus, if the gain of a channel is 1% slow,
CAL should be scaled by 1/(1 – 0.01).
These two constants control the CT phase compensation. No compensation
0
occurs when PHADJ_X = 0. As PHADJ_X is increased, more compensation
(lag) is introduced. Range: ±2¹⁵ – 1. If it is desired to delay the current by the
angle Φ:
0
PHADJ _ X = 2^{20 a ⋅ TANΦ}
b − c ⋅TANΦ
a = 1+ (1− 2^−9 )² − 2(1− 2^−9 ) cos(2πF₀T )
F₀T
=
F₀
F_S
0
b = (1− 2^−9 ) sin(2πF₀T )
c = 1− (1− 2^−9 ) cos(2πF₀T )
Page: 72 of 95
© 2005-2007 TERIDIAN Semiconductor Corporation
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