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

2.2.1 Components Selection

Gain of the system can be controlled at two stages, the gain stage and the integrator stage. Gain selection is highly influenced by the application. Some applications require stepping down high amplitudes of current to a measurable value for protection purposes where the currents are greater than 1kA. For protection applications, where the precise measurements are crucial, the current is stepped down to the mV ranges where the gain amplifier amplifies the signal, then the integrator (set to attenuate) attenuates all the noise in the system for precision measurements. This design has multiple gain settings ranging from 1V/V to 525V/V depending on the type and sensitivity of Rogowski coil where the gain of the integrator has been set to unity gain. These gain settings are selected at 100A of maximum current according to class 100 of ANSI C12.1 2024 standards and to accommodate to different sensitivities.