{"id":31352,"date":"2022-09-13T12:03:57","date_gmt":"2022-09-13T16:03:57","guid":{"rendered":"http:\/\/autosector.com\/?p=31352"},"modified":"2022-09-13T12:03:57","modified_gmt":"2022-09-13T16:03:57","slug":"1137141_lucid-motors-more-power-dense-easier-to-build-than-tesla","status":"publish","type":"post","link":"http:\/\/autosector.com\/?p=31352","title":{"rendered":"Lucid lays out why its motors are more power-dense and easier to build than those from Tesla"},"content":{"rendered":"

Lucid Motors calls its motor design miniaturized, and it\u2019s long boasted that the light and \u201cimpossibly compact\u201d motor in its Air electric sedan is lean enough to fit into an airplane carry-on.\u00a0<\/p>\n

Lean and small is only one aspect, however. Lucid\u2019s motors weigh just 67 pounds each and are capable of generating 670 hp\u2014yes, that\u2019s 10 hp per pound.\u00a0<\/p>\n

\"2022<\/p>\n

2022 Lucid Air<\/p>\n<\/div>\n

Further, Lucid\u2019s silicon carbide inverter, reduction gearset, and differential, packaged together, weigh about 163 pounds.<\/p>\n

It is very, very power-dense. And in a tech talk released by the company on Tuesday, Lucid CEO and CTO Peter Rawlinson and Powertrain VP Emad Dlala ran through the priorities the motors were designed around, and how power and efficiency, through low resistance and thermal management, have been part of the plan from the start\u2014along with ease of manufacturing.\u00a0<\/p>\n

You\u2019ll want to watch the entire presentation\u2014more than an hour\u2014for the physics lesson within, and you\u2019re bound to learn a lot not just about this unit but motors in general. But these four slides, comparing Lucid’s motor to motors from Tesla and Porsche, get to the gist of it.<\/p>\n

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\"Lucid<\/p>\n

Lucid weight of stator and rotor compared<\/p>\n<\/div>\n

\"Lucid<\/p>\n

Lucid motor weight compared<\/p>\n<\/div>\n

\"Lucid<\/p>\n

Lucid power density compared<\/p>\n<\/div>\n

\"Lucid<\/p>\n

Lucid power and motor weight compared<\/p>\n<\/div>\n<\/div>\n

Rawlinson notes that the project included going back to the physics and looking at the whole powertrain as a single holistic inertial system.\u00a0<\/p>\n

The two spend much time discussing the design of the stator, the static outer portion of the motor that, with the current shaped by the inverter, creates the magnetic field that rotates the rotor in the middle.\u00a0<\/p>\n

For instance, the stator for Lucid\u2019s six-pole permanent-magnet synchronous motor doesn\u2019t use copper-wire windings like many such motors, and it doesn\u2019t use hairpins either. Instead, for lower power losses plus ease of assembly, Lucid looks to a continuous-winding assembly that wraps into the stator with a limited number of welds. It\u2019s made with a CNC-controlled machine and a process that resembles weaving. Then a CNC-controlled mandrel helps align and insert the woven mesh.\u00a0<\/p>\n

The pair even poke a little fun at the workaround that Tesla resorted to in its motors for the Plaid\u2014a carbon-fiber shell that Rawlinson notes is the same sort of technology used in hydrogen storage for fuel cells, to hold tremendous pressure in. To scale that to high volume is going to be very expensive, Dlala speculates.\u00a0<\/p>\n

Lucid also cools its motor differently than Tesla, Porsche, or any other designs we\u2019re aware of. Lucid\u2019s strategy extracts whatever heat it can super-close to the slots rather waiting until the heat reaches outward. A middle channel in the stator functions as a manifold, running ATF (automatic transmission fluid) through narrow channels, helping extract heat through that mesh.\u00a0<\/p>\n

The busbars connecting the motor to the inverter are also the shortest possible, to reduce resistance (and thus heat). It\u2019s an advantage of the motor as it was designed in a single unit with the inverter.\u00a0<\/p>\n

\"Lucid's<\/p>\n

Lucid’s Rawlinson and Dlala presenting drive unit<\/p>\n<\/div>\n

Bottom line: Lucid emphasizes that its drive units are light, compact, efficient, power-dense, and can be scaled up.\u00a0<\/p>\n

Although Lucid doesn\u2019t actually lay out an efficiency analysis of the motor unit versus the unit from the Taycan<\/a> and Model S Plaid<\/a>, it implies based on the whole presentation that its motors also make a huge contribution to efficiency\u2014so much that, at the end,\u00a0<\/p>\n

To that point, Rawlinson ventures that the motor itself weighs so little\u2014just 11% of the overall battery-pack mass\u2014that if they can achieve that gain in efficiency from the unit\u2019s design it is essentially a \u201czero mass drive unit.\u201d<\/p>\n

That may be the point to help enable an advantage for Lucid in the future<\/a>, as it produces EVs that go farther with smaller battery packs<\/a> and, perhaps, a scaled-down version of this unit.\u00a0<\/p>\n