Pre-Charge [MSXV]

Link to Previous Proposed Changes for Pre-Charge:

Link:

Changes for MCI Rev 2.0

New Suggestions

• Motor controller capacitors are currently charged with a constant voltage source and series resistor. This is always 50% efficient. For a challenger vehicle, it might be better to have a switching circuit (buck topology) to charge with constant current (which would also be faster).

• Keep to 12V by removing DC DC inversion

• Add hall effect sensor

• Make simpler by removing irrelevant portions (e.g. fan control and thermistor may have been exclusive to MOV since shorts less of an issue?)

Research Summary

• Switching Circuit [Not Choosing This. Prefer Hall Effect Current Sensor]

  • https://www.powerelectronicsnews.com/power-supply-design-tutorial-part-1-2-topologies-and-fundamentals-continued/

  • https://www.maximintegrated.com/en/design/technical-documents/tutorials/2/2031.html

• Remove DC-DC [Using different change]

  • Remove all isolated 12V connection

  • Replace with VBAT

• Replace HV FET with solid-state relays [May not implement. No big advantages for changes]

  • Q1 and Q2 system to be entirely replaced with solid-state relays

    • End changes

      • One end from HV_IN

      • Other end to pre-charge

        • iso_latch_out might be removed?

    • Links

      • https://electronics.stackexchange.com/questions/261711/how-can-i-replace-a-relay-with-a-mosfet-transistor

        • Reverse it?

  • Part Search

    • Need 150V

    • https://www.digikey.ca/en/products/detail/bright-toward-industrial-co-ltd/AA58F/14302559

      • 1700V?

      • 120mA

    • https://www.digikey.ca/en/products/detail/panasonic-electric-works/AQY414SX/512420

      • 400V

      • 100mA

    • https://www.digikey.ca/en/products/detail/panasonic-electric-works/AQW210EHAX/512337

      • 350V

      • 120mA

      • Preferring This One

    • https://www.digikey.ca/en/products/detail/panasonic-electric-works/AQV257AX/646155

      • 200V

      • 250mA

• Add Hall Effect Current Sensor [Too complex to do in small time frame]

  • Remove entire middle section with Hall Effect Current Sensor

    • Must connect to IN+ and IN-

      • Unsure if AND gate and MOSFETs need to be changed

  • Links

    • https://www.bristolwatch.com/hall_effect/ac_hall_effect.htm

    • https://electronics.stackexchange.com/questions/338601/hall-effect-sensor-for-current-sensing-in-high-dc-voltage

  • Part search

    • Check ratings (Current, voltage, sensitivity)

      • Current

      • Voltage

        • 120V?

      • Sensitivity [Check]

        • 0.806mV/A?

          • 3.3/2^12 (12bit ADC)

          • https://www.st.com/content/ccc/resource/technical/document/datasheet/cd/46/43/83/22/d3/40/c8/DM00090510.pdf/files/DM00090510.pdf/jcr:content/translations/en.DM00090510.pdf

    • https://www.globalspec.com/learnmore/sensors_transducers_detectors/electrical_electromagnetic_sensing/electrical_current_sensors

    • https://www.ti.com/lit/an/slia086a/slia086a.pdf?ts=1647014926239

    • Part list

      • https://www.digikey.ca/en/products/detail/allegro-microsystems/ACS756SCB-050B-PFF-T/5400760

        • 50A

        • No Stock :/

      • https://www.digikey.ca/en/products/detail/lem-usa-inc/HO-8-NP-0000/4331974

        • 8A

        • No Sensitivity

      • https://www.digikey.ca/en/products/detail/tamura/L08P100D15/529421

        • 100A

        • No Sensitivity

      • https://www.digikey.ca/en/products/detail/tamura/L01Z200S05/529408

        • 200A

        • No Sensitivity

      • https://www.digikey.ca/en/products/detail/texas-instruments/TMCS1101A1BQDRQ1/14634037

        • 45A

        • 50 mV/A

      • https://www.digikey.ca/en/products/detail/texas-instruments/TMCS1100A4QDR/12696002

        • A?

        • 400 mV/A

• Simplify Isolated DCDC

  • U4

    • Original

      • Charge pump switch regulator

      • https://www.digikey.ca/en/products/detail/microchip-technology/tc7662beoa713/418710

    • New Change

      • https://electronics.stackexchange.com/questions/266187/efficient-alternative-to-a-charge-pump-for-stepping-up-a-3v-supply-to-3-3v

      • https://www.powerelectronictips.com/faq-what-is-a-charge-pump-and-why-is-it-useful-part-1-faq/

  • U5

    • Original

      • Optoisolator

      • https://www.digikey.ca/en/products/detail/broadcom-limited/HCPL-0211-000E/825261?s=N4IgTCBcDaIBIGEAKAZAtABjARm5jGAoiALoC%2BQA

    • New Change

      • https://electronics.stackexchange.com/questions/582157/alternative-to-optocoupler-in-circuit-design

  • U9

    • Original

      • DC DC Converter

      • https://www.digikey.ca/en/products/detail/xp-power/ISE1212A-TR/5320900?s=N4IgTCBcDaIIwBYDsAGAtGAnAVnXNAcgCIgC6AvkA

    • New Change

      • https://forum.allaboutcircuits.com/threads/dc-dc-converter-alternatives.23964/

• Smaller changes

  • Removing:

    • Fan control

      • Remove fan connector

      • Remove entire fan control sheet

    • Thermistor

      • Remove thermistor connector

      • Remove entire thermistor sheet

  • Add jumpers near AND gate to skip it