TIDUFB8 December   2024

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Key System Specifications
    2. 1.2 End Equipment
    3. 1.3 Electricity Meter
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 Voltage Measurement – Analog Front End
      2. 2.2.2 Current Measurement Analog Front End
      3. 2.2.3 Input Voltage
      4. 2.2.4 Clock
    3. 2.3 Highlighted Products
      1. 2.3.1 AMC130M02
      2. 2.3.2 MSPM0G1106
      3. 2.3.3 LMK6C
      4. 2.3.4 TLV76133
  9. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
    2. 3.2 Software Requirements
      1. 3.2.1 Formulas
      2. 3.2.2 Metrology Software Process
        1. 3.2.2.1 UART for PC GUI Communication
        2. 3.2.2.2 Direct Memory Access (DMA)
        3. 3.2.2.3 ADC Setup
        4. 3.2.2.4 Foreground Process
        5. 3.2.2.5 Background Process
        6. 3.2.2.6 Software Function per_sample_dsp ()
        7. 3.2.2.7 Frequency Measurement and Cycle Tracking
        8. 3.2.2.8 LED Pulse Generation
    3. 3.3 Test Setup
      1. 3.3.1 Power Supply and Jumper Settings
      2. 3.3.2 Viewing Metrology Readings and Calibration
      3. 3.3.3 Calibration
        1. 3.3.3.1 Voltage and Current Offset Calibration
        2. 3.3.3.2 Voltage and Current Gain Calibration
        3. 3.3.3.3 Active Power Gain Calibration
        4. 3.3.3.4 Offset Calibration
        5. 3.3.3.5 Phase Calibration
    4. 3.4 Test Results
      1. 3.4.1 Electricity Meter Metrology Accuracy Results
  10. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
      3. 4.1.3 PCB Layout Recommendations
        1. 4.1.3.1 Layout Prints
      4. 4.1.4 Altium Project
      5. 4.1.5 Gerber Files
      6. 4.1.6 Assembly Drawings
    2. 4.2 Tools and Software
    3. 4.3 Documentation Support
    4. 4.4 Support Resources
    5. 4.5 Trademarks
  11. 5About the Author

3.4.1 Electricity Meter Metrology Accuracy Results

After gain, phase, and offset calibration, the test results are shown in the following tables. Table 3-2 and Figure 3-13 show the active energy test results.

Table 3-2 Active Energy % Error Versus Current, 3mΩ Shunts, 230V
CURRENT (A) AVG ERROR% PF=1

Cos PHI = 1 (0°)

 AVG ERROR% PF=0.5i

Cos PHI = 0.5i (60°)

 AVG ERROR% PF=0.8c

Cos PHI = 0.8c (–36.87°)
0.1 –0.3943 –0.5190 –0.3493
0.25 –0.3770 –0.5150 –0.3113
0.5 –0.3707 –0.5147 –0.2917
1 –0.3437 –0.4487 –0.2627
2 –0.2897 –0.3633 –0.2510
5 –0.2527 –0.1237 –0.1720
10 –0.1090 0.0700 –0.0063
15 0.3040 0.3717 0.2200
TIDA-010960 Active Energy % Error Versus Current, 3mΩ Shunts, 230V Figure 3-13 Active Energy % Error Versus Current, 3mΩ Shunts, 230V

Table 3-3 and Figure 3-14 show the reactive energy test results.

Table 3-3 Reactive Energy % Error Versus Current, 3mΩ Shunts
CURRENT (A)

AVG ERROR%

Sin PHI = 1i (90°)

AVG ERROR%

Sin PHI = 0.5i (30°)

AVG ERROR%

Sin PHI = 0.8c (–53.13°)
0.1 –0.1147 0.2880 –0.7110
0.25 –0.3323 –0.1407 –0.4090
0.5 –0.3070 –0.1383 –0.3867
1 –0.2980 –0.1457 –0.3527
2 –0.2603 –0.1917 –0.2880
5 –0.0947 –0.2067 –0.1530
10 0.1030 –0.0213 0.0220
15 0.3437 0.3747 0.2523
TIDA-010960 Reactive Energy % Error Versus Current, 3mΩ Shunts Figure 3-14 Reactive Energy % Error Versus Current, 3mΩ Shunts

Table 3-4 and Figure 3-15 show the current RMS percentage error test results.

Table 3-4 Current RMS % Error at 230V, 3mΩ Shunts
CURRENT (A) %ERROR
0.05 –0.243
0.1 0.511
0.25 –0.0331
0.5 –0.257
1 –0.316
2 –0.378
5 –0.352
10 –0.215
15 0.0519
TIDA-010960 Current RMS % Error at 230V, 3mΩ Shunts Figure 3-15 Current RMS % Error at 230V, 3mΩ Shunts

Table 3-5 and Figure 3-16 show the voltage RMS percentage error test results.

Table 3-5 Voltage RMS % Error at 1A, 3mΩ Shunts
VOLTAGE %ERROR
10 0.004
20 –0.0125
50 –0.0004
75 0.000267
100 0.002
120 0.00583
140 –0.00643
160 0.0025
180 0.00555
200 0.0095
220 –0.00136
230 0.0130
240 0.0121
TIDA-010960 Voltage RMS % Error at 1A, 3mΩ Shunts Figure 3-16 Voltage RMS % Error at 1A, 3mΩ Shunts