TIDUEZ9B July   2022  – April 2023

 

  1.   Description
  2.   Resources
  3.   Features
  4.   Applications
  5.   5
  6. 1System Description
    1. 1.1 Isolated Current Measurement
    2. 1.2 Band-Pass Filter
    3. 1.3 Analog-to-Digital Conversion
    4. 1.4 Arc Detection Algorithm
    5. 1.5 Key System Specifications
  7. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 Current Transformer Circuit
      2. 2.2.2 Analog Band-Pass Filter
      3. 2.2.3 Analog-to-Digital Conversion
      4. 2.2.4 Power Supply
      5. 2.2.5 Debugging and Status Indication Options
    3. 2.3 Highlighted Products
      1. 2.3.1 TPS259474
      2. 2.3.2 TPS562202
      3. 2.3.3 TPS745
      4. 2.3.4 OPAx322
      5. 2.3.5 ADS8363
      6. 2.3.6 REF5025
      7. 2.3.7 TMDSCNCD280049C
  8. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware and Software Requirements
      1. 3.1.1 Hardware
      2. 3.1.2 Software
        1. 3.1.2.1 Arc Detection Theory
        2. 3.1.2.2 Software Implementation
    2. 3.2 Test Setup
      1. 3.2.1 ControlCARD Configuration
      2. 3.2.2 Setup for Hardware and Software Validation
      3. 3.2.3 Setup for Arc Testing
    3. 3.3 Test Results
      1. 3.3.1 Test Results of Hardware and Software Validation
      2. 3.3.2 Testing With Arcs
  9. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
    2. 4.2 Tools and Software
    3. 4.3 Support Resources
    4. 4.4 Trademarks
  10. 5About the Author
  11. 6Revision History

3.1.1 Hardware

For the initial bring-up, one TIDA-010231 board and one TMS320F280049C controlCARD (TMDSCNCD280049C) are necessary.

The controlCARD setup is found in ControlCARD Configuration.

A DC power supply is necessary to provide an auxiliary supply of 8 V to 16 V to the screw terminal J7. If this connector is oriented to the bottom, the left terminal is GND and the right terminal is the supply voltage.

For the initial low-voltage testing, a function generator is used to provide a sinusoidal input to the primary of the CT. With this setup the different parts of the analog front end, like the band-pass filter and the ADC can be tested.

For system testing with arcs, a DC source or a photovoltaic (PV) emulator, a solar inverter, and an arc generator are necessary. This design supports currents up to 10 A and voltages up to 800 V. Since this is a high-voltage test, the necessary safety measures must be in place, to prevent any accidents or injuries.

Table 3-1 lists and describes all test points and connectors.

Table 3-1 Connectors and Test Points
CONNECTOR OR TEST POINT DESCRIPTION
J1, J2, J3, J4

Inputs CH1, CH2, CH3, and CH4 are for arc detection. Connect these to the primary side of the current transformers. Connect in series with DC line between solar string and inverter. Can handle up to 10-A line current.
J5

120-pin HSEC connector for connecting different C2000 controlCARDs. Also compatible with 180-pin control cards.
J6

Debug connections. Pins 1 to 4 from left to right: GND, DACB, DACA, GPIO (GPIO34 for F280049C).

DACA and DACB can be used for some feedback signaling (not implemented) and the GPIO can be used for an external interrupt. The GPIO has external pulldown.
J7 Power supply connection. Connect a voltage between 8 V and 16 V to this terminal. GND is the left pin and VCC is the right pin.
TP1 Filter output and ADC input of CH1
TP2 Filter input of CH1
TP3 Filter output and ADC input of CH2
TP4 Filter input of CH2
TP5 Filter output and ADC input of CH3
TP6 Filter input of CH3
TP7 Filter output and ADC input of CH4
TP8 Filter input of CH4
TP9 2.5-V voltage reference
TP10 DACA
TP11 DACB
TP12, TP13, TP14, TP15 GND
TP16 5.25-V power supply for C2000 controlCARD
TP17 5-V analog power supply
TP18 3.3-V digital supply voltage