2024-08-11 Power Systems Meeting Minutes

Date

11 Aug 2024

Attendees and life updates

• @Frank Li - Going shopping

• @Aneri Patel - Moved back from Boston to Dallas. Sleep

• @Carolyn Hoang - Still working. Internship ends friday

• @Lakshay Gupta - Returned from California. Sleep

• @Nathan Hoang Nguyen - Went to Philip’s birthday, returned from Dallas. Alcohol

• @Changxu Liu - Sitting outside of a library.

• @Pratyush Patra - Came back from Michigan to Dallas.

• Watts - Won a soccer tournament.

Goals

• Quick introduction for new members

• Life updates

• Go through Power Systems Retrospective

• Discuss future projects

• Recruiting and Onboarding Discussion

Discussion Agenda

Future Projects

• Power Board Redesign

  • Description: Redesign of Power Board with increased amount of protection circuitry and utilization of power path controllers.

  • Replacing basic MOSFETs with ICs with better monitoring capabilities.

  • LTC4421 Datasheet and Product Info | Analog Devices

    • Power path controller IC

    • Recommended by Polytechnique Montreal.

    • Has connects two input sources to a common output.

    • We can use software to define voltage ranges, current limits, etc. parameters and also monitor these values

  • TPS25940

    • EFUSE IC.

    • Used by UW-Madison.

    • Shares the similar software versatility offered by the LTC4421.

• Smart Power Distribution Unit (aka Fuse box with power monitoring)

  • Description: A LV power distribution unit with several fused outputs, circuit protection mechanisms, and power monitoring.

  • Through this, we can record power consumption of every LV system and communicate it through CAN for debugging, data acq, etc.

  • The board will prevent issues caused by under or overvolting, short circuits, current spikes, etc.

  • Resettable fuses

• High Voltage redesign

  • Description: Current HV with an additional diode to allow array to power motor directly.

  • Diode considerations include reverse current leakage, voltage drop, etc.

  • Can be more long term (implemented in next car) but initial testing should be done this year.

• Active Precharge

  • Description: Replacing previous arbitrarily timed pre-charge with one based on actual state of hardware.

  • High-Voltage Solid-State Relay Active Precharge Reference Design

• DC-DC Convertor

  • Description: A ~300W flyback DC-DC Convertor capable of efficiently (>84%) converting ~120V down to 12V.

  • Pros:

    • It would be super cool if we made our own, and it would be a great learning opportunity.

    • Commercial DC-DC convertors are pretty pricey. The TEQ-300wir listed below is $703.57 (one designed by us could be just as expensive).

  • Cons:

    • The first couple iterations will surely blow up and we might not have a working model by the time comp arrives.

    • Hard to justify this project unless we can produce a better efficiency than the industry.

  • https://www.tracopower.com/sites/default/files/products/datasheets/teq300wir_datasheet.pdf?t=1723248002

    • Recommended by Appalachian State

    • $703.57

    • 89% efficient

• Supplemental Monitoring board redesign

  • Project with BPS

  • Current board just measures voltage. The new one should also be able to measure current, temp, and report any potential faults.

• Battery Characterization board

  • Open Source 18650 Lithium Battery Characterization System

Discussion Notes