TIDUFE9 August   2025

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Key System Specifications
    2. 1.2 Electricity Meters
    3. 1.3 Circuit Breakers
    4. 1.4 EV Chargers
    5. 1.5 Protection and Relay
    6. 1.6 Rogowski Coil-Based Current Sensor
      1. 1.6.1 Principle
      2. 1.6.2 Rogowski Coil Types
      3. 1.6.3 Integration Methods
      4. 1.6.4 Rogowski Coil Selection
  8. 2System Overview
    1. 2.1 Block Diagram
      1. 2.1.1 Differential Gain Amplifier
      2. 2.1.2 High-Pass Filter
      3. 2.1.3 Low-Pass Filter
      4. 2.1.4 Active Integrator
    2. 2.2 Design Considerations
      1. 2.2.1 Components Selection
        1. 2.2.1.1 RC Component Selection
        2. 2.2.1.2 RG Selection for Gain Setting
    3. 2.3 Highlighted Products
      1. 2.3.1 INA828
      2. 2.3.2 TLV9001
      3. 2.3.3 LM27762
  9. 3System Design Theory
    1. 3.1 Schematics to Layout
      1. 3.1.1 Rogowski Input Connectors
      2. 3.1.2 Gain Setting Resistor Chain
      3. 3.1.3 Gain Amplifier and High-Pass Filter Stage
      4. 3.1.4 Active Integrator Stage
      5. 3.1.5 Output Stage
      6. 3.1.6 Power Supply
  10. 4Hardware, Testing Requirements, and Test Results
    1. 4.1 Hardware Requirements
    2. 4.2 Test Setup
      1. 4.2.1 Full System Block Diagram
      2. 4.2.2 Test System
      3. 4.2.3 Rogowski Coil
      4. 4.2.4 TIDA-010986
      5. 4.2.5 ADS131M08 Metrology Evaluation Module
      6. 4.2.6 GUI
        1. 4.2.6.1 Getting Started
          1. 4.2.6.1.1 PCB Rogowski Coil Setup
          2. 4.2.6.1.2 TIDA-010986 Connectors
            1. 4.2.6.1.2.1 Input Terminal Block
            2. 4.2.6.1.2.2 Power Connection
            3. 4.2.6.1.2.3 Output Connections
          3. 4.2.6.1.3 ADS131M08 Metrology Evaluation Module Connectors
    3. 4.3 Test Results
      1. 4.3.1 Functional Test
      2. 4.3.2 Accuracy Measurements
        1. 4.3.2.1 No Load Conditions
          1. 4.3.2.1.1 Objective
          2. 4.3.2.1.2 Setup
          3. 4.3.2.1.3 Requirements
          4. 4.3.2.1.4 Results
        2. 4.3.2.2 Initial Load Operation Test
          1. 4.3.2.2.1 Objective
          2. 4.3.2.2.2 Setup
          3. 4.3.2.2.3 Requirements
          4. 4.3.2.2.4 Results
        3. 4.3.2.3 Accuracy Test at Different Load Conditions
          1. 4.3.2.3.1 Objective
          2. 4.3.2.3.2 Setup
          3. 4.3.2.3.3 Requirements
          4. 4.3.2.3.4 Results
        4. 4.3.2.4 Variation of Power Factor Test
          1. 4.3.2.4.1 Objective
          2. 4.3.2.4.2 Setup
          3. 4.3.2.4.3 Requirements
          4. 4.3.2.4.4 Results
        5. 4.3.2.5 Variation of Voltage Test
          1. 4.3.2.5.1 Objective
          2. 4.3.2.5.2 Setup
          3. 4.3.2.5.3 Requirements
          4. 4.3.2.5.4 Results
        6. 4.3.2.6 Variation of Frequency Test
          1. 4.3.2.6.1 Objective
          2. 4.3.2.6.2 Setup
          3. 4.3.2.6.3 Requirements
          4. 4.3.2.6.4 Results
        7. 4.3.2.7 Phase Sequence Reversal Test
          1. 4.3.2.7.1 Objective
          2. 4.3.2.7.2 Setup
          3. 4.3.2.7.3 Requirements
          4. 4.3.2.7.4 Results
  11. 5Design and Documentation Support
    1. 5.1 Design Files
      1. 5.1.1 Schematics
      2. 5.1.2 BOM
      3. 5.1.3 Layout Prints
    2. 5.2 Tools
    3. 5.3 Documentation Support
    4. 5.4 Support Resources
    5.     Trademarks
  12. 6About the Author

1.2 Electricity Meters

Electronic energy meters (e-meters) are used to accurately measure and monitor electrical energy consumption in residential, commercial, and industrial settings. These meters capture voltage, current, and frequency. E-meters often include metrology engines that use measured values to compute RMS voltage, RMS current, active power, reactive power, power factor (PF), Total Harmonic Distortion (TDH), phase shifts, frequency, and energy usage in real time.

Modern e-meters often integrate Rogowski coils, shunt resistors, and current transformers (CTs) as current sensors. Rogowski coils are advantageous due to the linear output, wide dynamic range, compact form factor, saturation immunity, high bandwidth, and temperature drift resistant. These sensors, combined with high-resolution ADCs and precision analog front ends, enable e-meters to deliver class 0.2 or better measurement accuracy.

To support time-of-use billing, load forecasting, and grid diagnostics, e-meters must maintain high accuracy across a wide dynamic range—from low standby currents to peak loads. Accurate current sensing is critical for both billing accuracy and compliance with regulatory standards like ANSI C12.1 and IEC 62053. Fast response time and stability over temperature and aging are also crucial, especially in smart grid systems where e-meters communicate usage data to utility providers for real-time monitoring and load management.