Texas Instruments TIDA-010243 Design Manual

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Design Guide: TIDA-010243
Cost-Effective, 3-Phase CT Electricity Meter Reference
Design Using Standalone ADC
Description
This reference design implements Class 0.1
three-phase energy measurement using a high-
performance, multichannel analog-to-digital converter
(ADC), which samples current transformers (CT)
at 8 kHz to measure the current and voltage of
each leg of the AC mains. The reference design
achieves high accuracy across a wide input current
range (0.01 A – 100 A) and supports high sampling
frequencies necessary for power quality features such
as individual harmonic analysis. An ADC sample
rate of 32 kSPS can be achieved when using a TI
Arm ® Cortex ® -M0+ host microcontroller for metrology.
The necessary software functionality is implemented
by porting the ADC Energy Metrology
MSPM0G3507 and can be compiled with Code
™
Composer Studio .
Resources
TIDA-010243
MSPM0G3507, ADS131M08
THVD1400, TRS3232E, TPS3840
TMAG5273, ISO6731, ISO6720
Ask our TI E2E
Load
Phase A
Phase B
ADS131M08
Phase C
VDD
GND
Voltage C
ADC
¡
Current A
CT #1
ADC
¢ £
Voltage C
ADC
¤ ¥
Current A
CT #2 ADC
 
CSn
SCLK
Voltage C
DIN
¦ § ADC
DOUT
Control +
Serial
RESET
Current C Interface
ADC
¨ © DRDY
CT #3
CLKIN
ADC
 
ADC
 
Source from Utility
TIDUF25 – JUNE 2023
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VCC
DVCC
GND
DVSS
10980.4 kWh
VCC
UART1 TX
MSP430
TPS3840
UART1 RX FR4131
RST/NMI
RESET
CT
GND
GND Button Button
1 2
ACT ISO-ACT
MSPM0G1107
ISO6720
REACT
ISO-REACT
GPIO
SPI CLK
SPI PICO VCC RS232_VCC
DTR
SPI POCI
GND RS232_GND
TPS709
RTS
RGND
Interruptible GPIO ISO6731
UART2 TX
TRS3232E
ADC_CLKIN UART2 RX
CLKOUT
GPIO
GND
GPIO
HFXIN
RE
16.384
MHz XTAL Board Header to RGND
HFXOUT WE
UART3 TX
External Radio/
THVD1400 VCC3
Radio Module
UART3 RX
Copyright © 2023 Texas Instruments Incorporated
Features
• 3-phase metrology for electricity meters that meets
ANSI C12.20 Class 0.1 active energy accuracy
requirements across 2000:1 input range
• Active and reactive energy and power, root mean
square (RMS) current and voltage, power factor,
and line-frequency calculations
• Isolated RS-232 and RS-485 with 5-kV
isolation
• Tested across 10 mA to 100 A and 9-V to 270-V
input range
• Software for energy metrology and displaying
results on a Microsoft
Applications
• Electricity meter
• Power quality meter
• Power quality analyzer
RS-232
Connection
RS-485
Connection
Cost-Effective, 3-Phase CT Electricity Meter Reference Design Using
Description
RMS
® Windows ® PC GUI
Standalone ADC
1