Defining Terms : Parallel vs. Series Hybrid

[ElectricTroy]

I've seen some people (especially magazines) confusing these terms. For example, calling Prius "parallel" and Civic "series" hybrid. Or vice-versa.


PARALLEL = Car can be pushed by both engine and/or motor. The power flows along a parallel path. Example: Prius & Civic

SERIES = The car is pushed *solely* by the electric motor. The gasoline engine recharges it, so the power path is connected in series. Example: EV1 w/ gasoline generator trailer.

[Guillermo]

Sorry you are mistaken,
Honda Hybrids are only Series systems (electric assist only works with gasoline engine on)
Toyota Hybrids are Parallel systems (because electric motor and gasoline engine can run independently.)

The terms used refer to two different types of basic electronic circuit designs.

[Rick Reece]

Agree with both of you. Troy's definitions fit the Diesel Electric submarine hybrids but does not fit the definitions given by the car makers. Have fun, RIck (A Retired Diesel Electric Sub driver ).

[Aaron Cake]

Troy's definition for series hybrid is correct. The auto manufacturer's skew the "hybrid" definition to make it mean what they want it to mean. Consider that none of the hybrids on the road today are actually hybrids.

[ElectricTroy]

Well the term "series" comes from electrical circuits, and it describes how the power flows:
Battery ---> Lightbulb ---> Radio ---> Battery

Same applies to hybrids:
Engine ---> Battery--> Motor ---> Wheels


...where the engine has NO connection to the wheels. Neither the Prius nor the Insight not use the above "series" design.

[Foxpaw]

Err, I don't think you can really argue a likeness to electrical circuits regardless. If you want to get technical with the electrical analogy, a series hybrid would be something that requires both motors to run all the time - as if you removed one you would break the circuit.

However, errr. Well, a series circuit would have a series of cumulative boosts to the power, while a parallel system would have an independant sum of all motor systems. Neither term really applies to mechanics like it does to electronics, however.

If I had to pick one, I would say that the Insight is MOST like a series system, as the output of the gasoline engine affects the output of the electric motor - so they are not truly independant. However, I don't think that electronic terms can be fairly applied to a mechanical situation which is completely different from the concepts of potential difference and resistance present in an electrical circuit.

I can't speak for the Toyota Synergy drive, as I am not familliar with it's operation.

[ElectricTroy]

You call it "mechanical" but I see the car as a giant "electrical" circuit. To me, a series hybrid is an electric car with unlimited range:

EV1 + generator trailer = series hybrid

Hi ElectricTroy:

___The GM EV-1 never was capable of towing a trailer with a generator. You are thinking of the T-Zero if I am not mistaken.

___Good Luck

___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___[email:djqftkjx]Waynegerdes@earthlink.net[/email:djqftkjx]

[ElectricTroy]

Actually I was thinking of the Toyota RAV4. Thanks for the correction.

Hi ElectricTroy:

___I have never seen one on a RAV4-EV but here is the T-Zero with its trailer in tow. While towing this monstrosity, you can only expect ~ 30 - 35 mpg when on the trailer unfortunately. That is pretty pathetic actually.

Range Extending Trailers



___Good Luck

___Wayne R. Gerdes
___Hunt Club Farms Landscaping Ltd.
___[email:3h9jmxoz]Waynegerdes@earthlink.net[/email:3h9jmxoz]