Tesla BMS HV Isolation sensing question

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Tesla BMS HV Isolation sensing question

Post by lawliet »

This is my first post in this forum, so let me know if I'm doing anything wrong.

I've been trying to understand how the Tesla model S senses if there is any isolation break from its HV system to chassi. In an youtube video video (link below), i found out that it uses a proposed method by Texas Instruments, however, I've been having trouble fully understanding it. On TI's Design Guide, there are two relays that connect the HV poles to chassi, but if I look at Tesla's BMS board it doesn't seem to have any. Anyone knows if there is a way to substitue both relays with something else, or maybe even a way of doing a continuous measurement (instead of discrete)?

Youtube Video:
https://www.youtube.com/watch?v=jEbeeP6 ... Ingineerix

TI's Design Guide:
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Re: Tesla BMS HV Isolation sensing question

Post by EV_Builder »

I understand you get that feeling especially when Ingeneerix makes the video but i think he shows a general approach in this video not specific the Tesla one. For one reason i think that because he doesn't state it's the plaid implementation etc. he shows an TI Reference design (actually the same as Tom De Bree used on github). If you can't find it on the BMS maybe Tesla opted to build it in the AC Charger or DC/DC converter (+12V onboard).
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