Integral Powertrain Begins Dyno Testing of New IPM Motor for Hybrids
22 April 2010
| Drawing of the new IPM motor. Click to enlarge. |
UK-based powertrain engineering consultancy Integral Powertrain has begun dynamometer validation testing of the first of a new family of advanced Internal Permanent Magnet (IPM) e-machines for hybrid vehicles. This latest IPM motor complements Integral Powertrain’s existing Surface Permanent Magnet (SPM) family of e-machines which has now been proven at ratings from 5 kW to more than 100 kW.
The new IPM design is intended for applications where high constant power speed range and minimum current requirements are paramount within hybrid motor applications. This makes the machines particularly suitable for integrated starter generator (ISG) systems; geared, high-torque traction motors; and power-split transmission applications.
| IPM Motor Specs | |
|---|---|
| Nominal torque (N·m) | 25 |
| Nominal power (kW) | 9 |
| Rated speed (rpm) | 17,000 |
| Overall diameter (mm) | 150 |
| Weight (kg) | 7.9 |
The initial machine has been designed for a belt-integrated starter-generator (B-ISG) application and will operate in conjunction with Integral Powertrain’s own VR-Pulley technology. (Earlier post.) This system provides reliable, Stop-Start and regeneration functionality along with an electrical ancillary-drive mode.
The stator design employs an 18-slot distributed winding and can be configured to run at nominal bus voltages between 14 and 800V. Integral Powertrain can also provide software and inverter hardware to support this range.
The new e-machine complements Integral’s high performance SPM architecture and allows coverage of a wide range of automotive applications:
| 6-pole/9-slot concentrated-winding SPM family | 6-pole/18-slot distributed-winding IPM family |
|---|---|
| Maximum dynamic response | Minimum phase current requirements |
| Typical rated speed up to 20,000 rev/min, specialist applications at higher speeds available | Typical rated speed up to 20,000 rev/min |
Automated Intelligent Design (AID) system. AID is a proprietary Integral Powertrain advanced engineering system which enables rapid customization of e-machine designs. The technology has been used successfully on a wide range of Powertrain engineering projects since 2003 with the e-machine modules developed in 2009.
The system is a comprehensive set of e-machine sub-system, design tools integrated directly into the CAD environment. AID for e-machines’ functionality includes:
- Electromagnetic concept-level & FE analysis
- FE Stress analysis
- Mechanical analysis and bearing system selection
- Thermal analysis for transient & steady-state rating
- Controls simulation and inverter matching
- Bill-of-Material and cost analysis
- Supply-chain and manufacturing integration
More compact (6KW/Kg) than any ICE unit around. A 100 KW unit (enough for most compact mid-size car) would be only weight 16.6Kg (36.6 lbs). How those it compare with other up-to-date e-motors?
Posted by: HarveyD | 22 April 2010 at 07:18 AM
That is incredible if it really does produce 6kW/kg. A Formula 1 engine is 95kg producing 580 kW which is 6.1kW/kg at 20,000rpm (though they are currently restricted to 18,000rpm for safety).
It's also an interesting coincidence that they say the IPM motor will do 20,000rpm as well.
More interesting is that this has more than double the torque of the formula 1 engine which really surprised me. I know electric motors are torque-y but I didn't realize Formula 1 engines were not.
Posted by: DaveD | 22 April 2010 at 07:59 AM
Formula 1 engines are intended to (=must) be used in combination with a gearbox so you cannot compare torque with an electric motor directly. At lower gears, torque increases considerably due to the speed reduction. On the other hand, the weight comparison should include transmission/reduction gearbox in both cases.
I suppse the electric motor would last longer than a Formula 1 engine...
Posted by: Peter_XX | 22 April 2010 at 08:10 AM
Good point Peter...I was assuming that the IPM would have either a reduction or transmission to match and so I should look at all of that and do a true apples to apples before drawing conclusions.
But I was still surprised that the Formula 1 engines didn't have more base torque. I guess those transmissions they use must be incredible beasts! I know the car is capable of doing zero to 100kmh in about 1 second (if it could get enough rubber on the road to keep traction) and 1.7seconds in the real world.
Posted by: DaveD | 23 April 2010 at 08:42 AM
Keep in mind that engine torque does not represent the auto acceleration.
A car with an engine producing 600 ft-lb of max torque and of 300 hp max at 3000 rpm would not accelerate as fast as with a 300 ft-lb torque engine with 500 hp at 7000 rpm - because of the gearbox.
Also a car at a certain speed will accelerate faster when at the engine is at peak hp rpm, not peak torque rpm - because of the gearbox and the gear selected.
Just gear the low torque, high rpm, little engine down by about 2:1 (more) and you get about twice the torque at the wheels.
Naturally aspirated engines get about the same max torque, in Ft-lb as displacement in cu-in, at mid rpm, and up to ~20% more if diesel or designed for high hp.
Posted by: ToppaTom | 25 April 2010 at 10:17 AM