🚀 go-pugleaf

On Sat, 17 May 2008 18:58:49 -0700 (PDT), kevin93
<kevin@whitedigs.com> wrote:

>On May 17, 12:00 pm, Robert Adsett <s...@aeolusdevelopment.com> wrote:
>> In article <fnFXj.506$mh5....@nlpi067.nbdc.sbc.com>, Joerg says...
><...>
>> > That's how the Toyota Prius works. Gets between 40mpg and 60mpg
>> > according to what owners told me.
>>
>> I was pretty sure the Prius was a parallel Hybrid (the electric motor
>> was in parallel to the ICE drive train). As opposed to a serial hybrid
>> where the final portion of the drive train is all-electric.  Some of the
>> proposed hybrids appear to be of the latter.
>>
>> The parallel hybrid does mean that neither motor needs to be sized large
>> enough for the full load.
><...>
>
>True, although the Prius is more of a Hybrid-Hybrid:  At low speeds it
>is a series hybrid with the majority of the engine power going to a
>generator and then to the motor driving the wheels with only a small
>amount directly from engine to wheels.
>
>At high speeds the situation is reversed and it acts more like a
>parallel hybrid with a large fraction, up to 100% of engine power,
>going straight to the wheels.
>
>This is done to maximize efficiency since the mechanical transmission
>has an efficiency of 95% or more but the electrical losses through two
>motor/generators are about 20%.

That is way past remarkably crappy motor and generator efficiencies.
Both are typically each 95 to 98 percent efficient.  Hell the antique
"Molly Long Legs" topped 99%.

>
>As you say the parallel approach also avoids the need to size the
>electrical equipment large enough for the full load - the generator is
>only 30KW even though the engine can output close to 60kW.  The motor
>driving the wheels is 50kW as an additional 20KW can come from the
>battery.
>
>kevin