electric motor tech

An induction motor uses coils on the stator and rotor. As shown here.



A permanent magnet synchronous motor uses coils for the stator and a magnet for the rotor. As shown here.



I think my first post in this thread summed it up.

I would add the permanent magnet AC electric motor in the Prius uses a rare-earth permanent magnet (neodymium iron boron alloy).

 

NO you did a good job. Ken's post was about a motor that used both coils for induction and permanant magnets for the field. It looked like a hybrid of the two. I had thought before that it was a normal synchronous motor.

 

The first set of Plasma TV’s used liquid cooling to keep the FET’s from over heating. With time FET’s will become more efficient and the technology to drive them will always evolve. Soon we will have a pure electric car with zero active cooling.

I am typing this on an Atom based netbook with no active cooling.

 

Alternators are less efficient, the mg's substitute more complex electronic controls for increased efficiency. There are no technical difficulties to producing inverters that operate at high temperatures, but liquid cooling is a engineering choice to have smaller less expensive inverters. I would go with your assumption of high replacement costs due to uniqueness to the GIII prius, but they also should be highly reliable.

It can be liquid cooled or air cooled. Toyota and nissan have chosen air cooling, gm and tesla have chosen air cooling. With the small pack size of the standard and phv prius air cooling seems fine. BEV and phev have different chemistries than other batteries so they are unlikely to catch fire, but heat can reduce capacity and useful life.

Tesla CEO: Nissan's LEAF Battery Is

Yes, since power is converted to electricity the friction brake pads are used less. Less use means longer life.

 

Yes. Generally Prius brakes die from rust, not use.

Tom

 

And a hybrid permanent magnet induction motor does both, with the magnet dominating at low power levels, while induction dominates at higher power.

Tom

 

This is a wee bit off topic, but does anyone know why the repair manual has separate sections for both brush and brushless-type motors for the Power Steering System? Is it a regional issue (e.g., European vs. North American models)?

 

For the US, I have heard that the slow steering in the II-IV models has the brush type and the quicker rack in the V has the brushless.

I saw one parts catalog that looked like maybe more cars get the quick steering in other countries.

 

Models I-IV use a brush motor and different steering rack. Model V has a brushless motor. It seems like a strange choice, I can not believe the brushless motor is much more expensive, but when you are talking millions of cars every yen counts.

didn't mean to repeat information, but the reply above mine didn't show up when I posted.

 

My swimming pool filter pump claims to use hybrid car technology. It is a 220 volt permanent magnet ac motor. It is made by Pentair and the model is Intelliflo VF. There is info online about it. It has a digital readout under a weather cover and the speed varies up & down depending on the way it is programmed. Hybrid enthusiasts might want to read up on this thing. Its kinda cool if there is such a thing as a cool pool pump. It saves me a lot on my power bill and its very quiet. The readout shows the watts or rpm. I'm usually drawing aprox 265 watts except when I'm vacuuming the pool when I ramp it up all the way. Thats a lot less power than an induction motor pool pump.

 

I don't have the specification about the Gen3 IPM motor, but following is a good study about Gen2 system including IPM motor.
Information Bridge: DOE Scientific and Technical Information - Sponsored by OSTI
On the page-34 (page-43 of PDF) of the document, the motor efficiency map is shown as attached.

Please note that the Gen2 motor is high torque and low rpm configuration to drive the ring gear directly. The Gen3 motor is low torque and high rpm configuration to drive the ring gear via 2.636 reduction gear.

Ken@Japan

 

I'm not sure what is the exact reason that Toyota uses low torque high rpm configuration for recent design.
We can guess on following area...

• higher efficiency
• smaller and lighter motor
• cost reduction to make motor

Anyway, following is a table about Toyota's design trend.

	year	model	power	torque	reduction gear
1	1997	NHW10 Prius	30kW@940-2000rpm	305Nm@0-940rpm	no reduction gear
2	2000	NHW11 Prius	33kW@1040-5600rpm	350Nm@0-400rpm	no reduction gear
3	2003	NHW20 Prius	50kW@1200-1540rpm	400Nm@0-1200rpm	no reduction gear
4	2005	RX400h/Hilander Hybrid	123kW@4500rpm	333Nm@0-1500rpm	single stage reduction gear
5	2006	Camry Hybrid	105kW@4500rpm	270Nm@0-1500rpm	single stage reduction gear
6	2006	GS450h	147kW@5615-13000rpm	275Nm@0-3840rpm	two stages reduction gear
7	2007	LS600h	165kW@6400-10240rpm	300Nm@0-4352rpm	two stages reduction gear
8	2009	RX450h	123kW@4500rpm	335Nm@0-1500rpm	single stage reduction gear
9	2009	ZVW30 Prius	60kW@2768-4000rpm	207Nm@0-2768rpm	single stage reduction gear

Please note that GS450h and LS600h are powerful vehicles and run wider speed range, therefore they have two stages reduction gears to run efficiently on both low speed and high speed.

Ken@Japan

 

Just, FYI...
The important specification for the hybrid battery is instantaneous power rather than capacity.

Prius history is reducing battery capacity, but their performance and fuel economy numbers are improving. That's the innovation.

Ken@Japan

 

Hi Ken,

I think the main reason the shift to the high-speed motor Prius transmission for Gen III , is to improve the engine to wheels efficiency. This configuration eliminates one gear set between the ring gear and the axle. The Prius is primarily a parallel hybrid. So, engine to axle is an important efficiency to have best, for 70 mph highway cruising (as the EPA test was changed to accentuate that).

 

I think it is doable to eliminate drive chain using bigger drive gear set even with a larger size of MG2.

I think the better EPA number is not caused by the single reason.
There are a lot of areas to improve efficiency Toyota did, such as...

• more efficient ICE
• more battery power
• higher (500V->650V) drive voltage
• better cooling on inverters
• and so on

Ken@Japan