Fisker Orbit To Get Protean In-Wheel Electric Motors

JUN 29 2018 BY MARK KANE 17

Fisker’s Orbit, an all-electric autonomous shuttle announced in late 2017, is to be equipped with in-wheel motors supplied by Protean Electric.

Fisker selected in-wheel motors because it doesn’t intrude on the interior so the Orbit will be a low-entry, flat floor vehicle.

The Protean Pd18 in-wheel motors are rated for 80 kW and 1,250 m (on wheels) at peak. Two of those will enable 160 kW of power, which seems enough for the job as the shuttle bus is far from a racing car.

However, for customers interested in higher power, the option of four motors (320 kW) and all-wheel drive is to be available.

Protean Electric ProteanDrive Pd18

Tests of the first prototypes are expected later this year, while deployments on a set route are scheduled for next year.

ProteanDrive Pd18 Features:
  • Packaged into an 18” wheel rim
  • Torque demand control over CAN bus
  • High torque direct drive (no gearing) for optimal efficiency
  • Permanent magnet synchronous machine with outer rotor
  • Integrated power and control electronics with distributed architecture
  • Integrated friction brake
  • Integrated wheel bearing
  • Development in accordance with the ISO26262 Functional Safety Standard
  • Design lifetime of 300,000km and 15 years with verification through bench and vehicle durability testing
  • Designed to exceed, and tested in line with, major automotive manufacturers’ EMC standards

Protean Electric ProteanDrive Pd18 spec is available here.

Source: Autocar, Green Car Congress

Categories: Fisker / Karma


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17 Comments on "Fisker Orbit To Get Protean In-Wheel Electric Motors"

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(⌐■_■) Trollnonymous

Mark, did IEV’s do a piece on this?

Texas Rebate excludes Tesla?


The Protean/PML motors are almost 80 pounds with low torque, acceleration is sluggish.


But with 4 of them not so bad if you think about it…


Four makes handling even worse.


Four 80-lb motors added to the unsprung weight will make handling terrible, and likely won’t improve the ride quality either. That’s in addition to sluggish acceleration, and what about the cogging problem?

Of all the EVs originally announced to use in-wheel motors, I think all of them with only one single exception were switched to inboard motors by the time the model actually went into production. In-wheel motors are too expensive, and break down much faster than other parts on an EV due to all the pounding they receive. Despite the theoretical advantages, they have been shown in practice to be just a bad idea, period.


There is a whole battalion of two-wheeled EVs of various forms and sizes using wheel hub motors. They do have their trade-offs, but they are perfectly practicable — and often the trade-offs are deemed favourable.

For more precedent, the Lohner-Porsche plug-in hybrid coach was produced in series from 1900 till 1905 with wheel hub motors 😛


Gees. 80 lbs? Thats a lot to add. In fact, that pretty much doubles the weight of a wheel/axle.

Something like a monorail, or hyperloop would make great sense, but not cars, vans, trucks.


Whenever an EV is announced with in-wheel motors, you can be sure it will be just a concept vehicle or, at best, an extremely low-production “hand built” model. Not mass produced at all.


InWheel Motors are a “Bad Idea”


For a shuttle that goes 40 mph with only a few people it could work.


And definitely on a tarmac or on very flat city roads at slow speed.


Actually, there are good places for these. I would even think that golf carts might find them useful.
BUT, not a car.

Muhammad Asif

About price of Electric shuttle please tell me I am from Pakistan


It’s a little strange to see EV supporters claim that a technology is absolutely and eternally impossible due to motor weight, after they’ve had to fend off years of claims that EVs were absolutely and eternally impossible due to battery weight. I recall when a good motor weighed several pounds per horsepower. Now there are motors out there which have several horsepower per pound. At some point, you can offset the weight of conventional brakes sufficiently that it becomes worth integrating the wheels and motor housing, or even build airless tires around those.

Now if you’re going to talk about more specific problems like maintaining the proper gap between stator and rotor, or some other mechanical reality, that’s more legitimate.


Not impossible, just not the best for handling. They chose them to gain more room inside.


It is all about the function/performance/reliability/cost tradeoffs made in design and there will be specific circumstances where in-wheel motors will be effective.


U are not paying attention.
Assume that the motors did fine on acceleration. Then you have the issue of handing. The extra weight on the wheels is BAD for handling. Really bad.
In addition, we are now talking 4 motors, not 2 or 1, AND you have to deal with the extra drag of 2 motors when you are freewheeling front or back.