TIDUF98 October   2024

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 End Equipment
      1. 1.1.1 Electricity Meter
    2. 1.2 Key System Specifications
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Highlighted Products
      1. 2.2.1 ADS131M03
      2. 2.2.2 MSPM0L2228
      3. 2.2.3 THVD1400
      4. 2.2.4 ISO6731
      5. 2.2.5 DRV5032
    3. 2.3 Design Considerations
      1. 2.3.1 Design Hardware Implementation
        1. 2.3.1.1 Analog Inputs
          1. 2.3.1.1.1 Voltage Measurement Analog Front End
          2. 2.3.1.1.2 Current Measurement Analog Front End
      2. 2.3.2 Energy Metrology Software
        1. 2.3.2.1 Software Architecture
        2. 2.3.2.2 Setup
          1. 2.3.2.2.1 Clocking Scheme
          2. 2.3.2.2.2 SPI
          3. 2.3.2.2.3 UART Setup for GUI Communication
          4. 2.3.2.2.4 Real-Time Clock
          5. 2.3.2.2.5 LCD Controller
          6. 2.3.2.2.6 Direct Memory Access
    4. 2.4 Hardware, Software, Testing Requirements, and Test Results
      1. 2.4.1 Required Hardware and Software
        1. 2.4.1.1 Cautions and Warnings
        2. 2.4.1.2 Hardware
          1. 2.4.1.2.1 Connections to the Test Setup
          2. 2.4.1.2.2 Power Supply Options and Jumper Settings
        3. 2.4.1.3 Calibration
      2. 2.4.2 Testing and Results
        1. 2.4.2.1 Test Setup
          1. 2.4.2.1.1 Viewing Metrology Readings and Calibration
            1. 2.4.2.1.1.1 Viewing Results From LCD
            2. 2.4.2.1.1.2 Viewing Results From PC GUI
        2. 2.4.2.2 Electricity Meter Metrology Accuracy Testing
        3. 2.4.2.3 Electricity Meter Metrology Accuracy Results
  9. 3Design Files
    1. 3.1 Schematics
    2. 3.2 Bill of Materials
    3. 3.3 PCB Layout Recommendations
      1. 3.3.1 Layout Prints
    4. 3.4 Altium Project
    5. 3.5 Gerber Files
    6. 3.6 Assembly Drawings
  10. 4Related Documentation
    1. 4.1 Trademarks
  11. 5About the Authors

2.4.2.3 Electricity Meter Metrology Accuracy Results

For the following test results, gain, phase, and offset calibration are applied to the meter. At higher currents, the % error shown is dominated by shunt resistance drift caused by the increased heat generated at high currents.

Table 2-3 Active Energy % Error Versus Current, 200µΩ Shunts
CURRENT (A) AVG ERROR % PF = 1, cos PHI = 0° LIMIT (%) [CLASS 0.5]

IEC 62053-22 (PF = 1)

 AVG ERROR % PF = 0.5i, cos cos PHI = 60° LIMIT (%) [CLASS 0.5]

IEC 62053-22 (PF 0.5i/0.8c)

 AVG ERROR % PF = 1, cos PHI = –36.87°
0.10 0.322 1.0 0.571 1.0 0.563
0.50 0.105 1.0 -0.017 1.0 0.227
0.75 0.089 1.0 -0.073 1.0 0.212
1.5 0.058 0.5 -0.101 0.6 0.165
3 0.063 0.5 -0.123 0.6 0.150
7.5 0.053 0.5 -0.156 0.6 0.144
15 0.041 0.5 -0.161 0.6 0.124
30 0.005 0.5 -0.187 0.6 0.110
60 –0.002 0.5 -0.265 0.6 0.077
75 -0.061 0.5 -0.304 0.6 0.008
100 -0.181 0.5 -0.502 0.6 –0.129
TIDA-010940 Active Energy % Error Versus Current, 200-µΩ ShuntsFigure 2-11 Active Energy % Error Versus Current, 200-µΩ Shunts
Table 2-4 Reactive Energy % Error Versus Current, 200-µΩ Shunts
CURRENT (A) AVG ERROR % sin PHI = 1i (90°) LIMIT (%) [CLASS 0.5]

IEC 62053-22 (sin PHI = 1, 90°)

 AVG ERROR % sin PHI = 0.5i (30°) LIMIT (%) [CLASS 0.5]

IEC 62053-22 (sin PHI = 0.5i/0.8c, 30°/-53.13°)

 AVG ERROR % sin PHI = 0.8c (-53.13°)
0.10 0.186 0.623 -0.374
0.50 0.088 2.0 0.322 –0.177
0.75 0.074 2.0 0.314 –0.148
1.5 0.051 1.0 0.258 2.0 –0.116
3 0.046 1.0 0.252 1.0 –0.102
7.5 0.043 1.0 0.255 1.0 –0.092
15 0.037 1.0 0.2 1.0 –0.095
30 0.037 1.0 0.230 1.0 –0.095
60 0.019 1.0 0.222 1.0 –0.126
75 -0.033 1.0 0.154 1.0 –0.190
100 -0.131 1.0 -0.006 1.0 –0.332
TIDA-010940 Reactive Energy % Error Versus Current, 200-µΩ ShuntsFigure 2-12 Reactive Energy % Error Versus Current, 200-µΩ Shunts
Table 2-5 Current RMS % Error at 120V, 200-µΩ Shunts
CURRENT (A) %ERROR
0.025 –23.562
0.05 –8.155
0.1 –2.049
0.25 –0.492
0.5 –0.203
1 –0.100
2 –0.050
5 –0.049
10 -0.021
20 -0.037
30 -0.023
40 -0.027
50 -0.015
60 0.002
70 0.011
80 0.021
90 0.034
100 0.064
TIDA-010940 Current RMS %Error Versus Voltage, 9V to 270V, 200-µΩ ShuntsFigure 2-13 Current RMS %Error Versus Voltage, 9V to 270V, 200-µΩ Shunts
Table 2-6 Voltage RMS % Error at 10A, 200-µΩ Shunts
VOLTAGE (V) %ERROR
9 0.021
10 0.037
30 0.027
50 0.009
70 0.004
90 –0.006
100 0.008
120 –0.004
140 -0.006
160 0.001
180 0.018
200 -0.002
220 0.011
230 0.023
240 0.009
260 0.027
270 0.025
TIDA-010940 Voltage RMS %Error at 10A, 200µΩ Shunts Figure 2-14 Voltage RMS %Error at 10A, 200µΩ Shunts