Understanding the Tesla Model S Power Electronic Components

Join me on a journey through 74 feet (22.56 meters) of high voltage cable through 10 different power electronics components of a 2015 and later Tesla Model S AWD.

TIMELINE:
0:00 Start
0:10 Introduction
0:50 Model S cables and common components
1:16 MUST SEE Orange cable core and shielding
2:38 Common component 1 - The Charge Receptacle
4:00 The charging receptacle cable size (50 sq mm) compared to the Tesla Model 3 cable size (95 sq mm)
6:12 Common component 2 - The On-Board Charger Module (48A 11.52 kW)
7:48 Single Phase or three-phase power input ports
10:10 The Interlock circuit
11:50 See the internal parts and connections of the on-board charger
12:28 MUST SEE The AC power input path through the on-board charger
12:55 AC voltage needs to be boosted to ~400V
13:39 The DC power output path through the on-board charger
14:10 The DC power input path through the on-board charger
14:32 The DC contactors used when supercharging the battery
15:47 A Safety Warning that should have been at the start of the video
16:54 The DC output from the on-board charger
17:26 Common component 3 - The Rapid Splitter (Front Junction Box)
17:50 The connection to the high voltage battery through the rapid splitter
18:22 The function and internal connections of the Rapid splitter
22:20 The position of the Rapid Splitter in the vehicle under the rear seat
22:50 Common component 4 - The rear motor inverter
24:54 Summary of the high voltage components in the rear of the vehicle
25:48 MUST SEE Pyrofuse Pack battery cable tag and pyrotechnic fuse
26:22 The standard 1300 amp fuse
26:40 The 2000 amp pyrotechnic fuse and its internal components
30:30 Why the battery fuse is needed
31:45 The high voltage components and cables at the rear of the vehicle
32:28 Common component 5 - The High Power Distribution Module (HPDM) (Front junction block)
33:20 See the four internal fuses and circuit board inside the HPDM
34:22 Another Interlock switch
34:48 The battery coolant heater control circuit
35:48 The high voltage connections from the Rapid Splitter to the HPDM
36:49 Common component 6 - The front motor inverter
38:17 The NVH Mat covering the front Drive Unit and motor
39:55 Common component 7 - The electric air-conditioning compressor (40A Fuse)
41:23 Common component 8 - The 2500 Watt DC to DC converter (30 A Fuse)
42:05 DC to DC converter output of 178 amps at 14 volts
43:03 the DC to DC converter charges the 12V battery
44:16 Common component 9 - The high voltage battery coolant heater (30 A Fuse controlled)
46:18 Common component 10 - The Positive Temperature Coefficient (PTC) Cabin Air Heater (40A Fuse)
48:18 The high voltage components and cables at the front of the vehicle
49:29 Almost all Electric Vehicles (EV) have the same common components shown in this video
50:39 Additional EV training is available for you.
51:12 Wrap up and summary

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[matthewdillon]

As a Tesla employee, it is actually insane how well done this video is made and is actually really impressive how you were able to explain this so well without any schematics or trainings.

[arachnidkalven]

The man is an absolute goldmine of explanation power.

[TheCaphits]

Thank you so much for producing these videos for people who do not attend Weber State. This is really high quality stuff and it's very enjoyable with you as a presenter!

[radman]

Your courses are superior to any institutional automotove training I have had in my career, including what is done at the manufacturer level. Your school and students are very lucky to have you, John.

[jacekkubiak]

I am a professor in France about automation and I think that i am far from a such level of quality of explanation. It is impossible to stop vidéo. Great job, thank You.

[terryspears]

I worked 42 years in industrial electronic controls with “Big Oil” and “Gas” companies. You are an excellent presenter of this technical information.

[andyblackpool]

I'm not a full time mechanic but I found this video absolutely riveting. Excellent tutor, you made everything so easy to follow; I never got lost once! This tutorial will be a fantastic asset to anyone (car mechanics / car technicians ) involved in the emerging electric car industry. Loved it, very well done sir, thank you.

[adityabhat]

This guy has god level skills of teaching. ...I take a bow to your teaching skills

[JohnBrown-dzyu]

As someone who loves how it's made videos, tesla's, and being an EE this video is so interesting. Can't wait for the model 3 high power component examination.

[maxtorque]

The fundamental difference of course between AC and DC charging is the location of the charging current control!

For AC charging, being low powered, the current limitation is never really the battery (48 amps of charge current is totally trivial to a battery that can deal with kA of current!) but is the EVSE (Electric vehicle supply equipment, ie the off board charger and supply wiring, the bits normally screwed to the wall of your house). When an AC charger is connected, the pilot signal is used to limit max charging current and to signal the EVSE to close it's AC relay(s) to switch voltage onto the AC inputs of the on-board charger, and from then on, it is the Onboard charger that effectively acts to control actual charging current. It becomes as far as the EVSE is concerned, a varriable impedance to neutral, (it's an isolated AC/DC architecture to deal with the votlage difference and to ensure galvanic isolation between battery and AC supply earth potentials). Normally, you'd expect that system to quickly ramp to the maximum current the EVSE has requested (typically between 12 and 30 Amps) and only to reduce that current when the battery reaches it's State of Charge limit (ie it's fully charged ) At no time is the EVSE "controlling" the charging current, although it can obviously open it's relay and completely stop charging (in the case of a fault, or the user stopping charging) and it can reduce it's max charging limit if it considers some limiting factor to come into play (temperature of the charging handle, cable, or internal temp of the EVSE itself)

For DC charging, things are very different. For a start DC charging uses a serial data link (CAN (Tesla/CHADEMO)or GreenPlug HomePhi (CCS)) to continuously arbitrate and exhcange data between the off board charger and the vehicles HV control system. Here, that data link is used to control the charging process, but here the off board charger is responsible for controlling the charging current. It's is the OFF Board charger that requests the vehicle to connect the DC charge harness to the battery, via those large contactors in the on-board charging unit. But before that happens, top avoid excessive inrush currents, the DC charger must match the batteries voltage (to within a small tollerance (aorund 5v typically) and to apply that voltage to the DC charging port on the OBC. The vehicle monitors the voltage on both sides of the DC contactors in the OBC, and when matched, closes those contactors, effectively now providing a direct, ultra low resistance feed straight iinto the vehicles battery. The Off board DC fast charger now will modulate the voltage it applies to the DC charging port to drive current into the battery at the rate the vehicle requests. Because the charging power is so much higher (up to 250 kW, massively more than the 22kW max from AC (3ph)charging) this current is effectively limited by all sorts of complex factors, from battery SoC, to battery temperature, and component temps within the charging system (including the temperature of the charging handle and cabling, which are water cooled for >125 kW applications)
In this case, the DC fast charger is acting as the DC/DC element. This is because a 250kW DC/DC is a large, expensive device, and it would be stupid to include it in the vehicle as opposed to simply installing it at the charging location (in the same way our ICE cars doing have on board refuelling pumps, but rely on fuel being pumped onboard by an external pump)

In all cases, the sequencing, fault checking, and functional states are complex, and require a host of system to interact, from EVSE, to OBC to BMS etc!

[forrest]

That pyro fuse is actually much more clever than you let on in your description. The pyro part is identical to the one used on the 12v battery, which is great at handling high current since it’s essentially a very low resistance bus bar, but it’s not at all rated for high voltage. It’s not an issue if it never opens because the voltage drop should always be close to zero. Unfortunately, if opened under load that component alone would experience the full 400V of the battery causing quick melting and a likely "thermal event”. To prevent that, the engineers added the 2 normal HV low amp ceramic fuses you see on either side of the pyro device in parallel. These fuses have a small but non-zero resistance, so they get almost none of the current in normal operation. Those fuses are however rated to fuse the full battery voltage without arc flash, so as the voltage rises during the pyro disconnect the current starts to flow through the fuses instead. Those fuses open the overall battery circuit once they get above 40A without any arc flash. Interesting enough this was just an intermediate design, and in the Model 3 they implemented a pyro fuse that could actually safely handle the full voltage without any of the extra components. I do love the ingenuity that went into this design, great example of a "what do we have lying around here that can solve this problem’?

[anderssejer]

I am not even half way through the video but had to stop it so that I was sure to remember, and to tell you that this is SO nicely explained.
Everything makes sense in some way, so many nice details, and (until now) not anything redundant.
Thanks for a great video!

[andrewsmactips]

When I think of Professor Kelley, one overriding word comes to mind: Clarity.

[lindenschmitt]

You have many admiring students. You are a supurb, world class instructor. You are the Rush Limbaugh of of Weberauto instructors on YouTube. Congratulations Professor John D. Kelly for teaching the latest EV technology, the USA needs more unsung Hero's like you. God bless you and keep up the class act academic profession.

[ricardofelippe]

For sure it was not a long video Professor. it was perfect full of information, tips and details. Again simply fantastic.

[ModelA]

THANK YOU for doing this!! These cars are the polar opposite of the cars I work on at my channel. Literally!

[santiagohills]

My daughter’s studying engineering at one of your conference rival schools (Cal Poly), so right now I’m not exactly in a position to financially support the good work you’re doing at Weber State. But I sure do appreciate the amazing work you’re doing! I like understanding what my Bolt EV is thinking...

[immigrantlife]

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[zeez]

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👍greeting from England🇬🇧

[DMT]

As a former Auto Electrician, this is the most informative and thorough explanation I've ever seen. Millions of EV owners are obviously what lies beneath their vehicle. Thank you, Professor. Much respect. Take care.