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compareable motors.....ac vs dc
2

compareable motors.....ac vs dc

compareable motors.....ac vs dc

(OP)
I am wanting to find a AC electric motor that will run on 110vac or 220vac that will have approxamately the same output as a 10hp DC electric motor that runs on a 96vdc to 144vdc. How would one go about figureing out what the comparable motor would be?

RE: compareable motors.....ac vs dc


What is your mechanical load (power, speed, ..)
What is type of DC Motor, separately excited, shunt or series?

It depend on your mechanical load (Power and speed), then you can select Ac Motor suitable for your mechanical load

·    If your load needs constant speed regardless variation of load or electrical power supply, then use Induction motor with variable frequency control
·    If your load normal, does not need constant speed, then use Induction motor with normal AC supply

Regards,

RE: compareable motors.....ac vs dc

You need to figure out what the relevant criteria are, and then pick an AC motor that exceeds those criteria.  In addition to Mohsen's comments, you might need to check the torque/speed curve too, to make sure the motor starts OK, etc.

Um, otherwise, the trivial answer would be, "a 10hp 110/220vac motor."

RE: compareable motors.....ac vs dc

Suggestion: Please, would your provide nameplate data of your DC motor. If it is the DC series motor, there may be the more difficult match with an AC motor.

RE: compareable motors.....ac vs dc

(OP)
I am in the process of building a hybrid car which will use a portable generator as a power source. The web site below makes conversion kits for cars...but it is dc only. They basically told me that useing a ac generator is impossible. I figure with a generator that can produce 110 or 220 would be a good power supply. If a generator can run 10 to 14 hours on 5 gallons of gas.....well I think you get the picture. I am looking for an AC motor that will replace the dc motor in their kit. I haven't gotten all of my numbers together yet to figure the load. Thanks for the help so far.

RE: compareable motors.....ac vs dc

(OP)
I am in the process of building a hybrid car which will use a portable generator as a power source. The web site below makes conversion kits for cars...but it is dc only. They basically told me that useing a ac generator is impossible. I figure with a generator that can produce 110 or 220 would be a good power supply. If a generator can run 10 to 14 hours on 5 gallons of gas.....well I think you get the picture. I am looking for an AC motor that will replace the dc motor in their kit. I haven't gotten all of my numbers together yet to figure the load. Thanks for the help so

far.http://www.electroauto.com/catalog/kits.shtml

RE: compareable motors.....ac vs dc

It seems to me like you will need a variable speed drive, in order to soften the repeated starts and to vary the speed.

10hp motor has rated torque T = 5250*P//N = 52,500 /N where T in lbf-ft and N in rpm. Breakdown torque for standard design B induction motor is around 250% of that.

There was a long thread about selecting a motor for a dragster. You might want to search for that.

I'm sure it won't be an easy application. There are a lot of folks on the board who can tell you about vfd applications (much moreso than me).  It would probably help them to know specifically roughly how much mass you might have, how fast you want to accelerate, what peak speed you want, etc.

RE: compareable motors.....ac vs dc

Suggestion: Please, notice that the electric vehicle technology tends to have small dimensions and very small weight. It is somewhat related to shipboard technologies.
Theoretically, you will need a generator, motor drive with associated controls, and storage battery since there is a need for conservation of energy through the energy regeneration.
There are already many cars built and marketed, especially by Japanese.

RE: compareable motors.....ac vs dc

I'd strongly suggest sticking with the DC plan.

If you are planning on constantly running the generator, with no battery, then the whole point of the hybrid vehicle seems to go out the window.  You're going through 2 power conversions (gas-->electric-->mech) instead of one (gas-->mech), which would likely mean a decrease in total efficiency.  Flywheels or other storage devices might change this argument, but most other electical and mechanical storage devices are even worse than batteries.

If you are planning to build a typical hybrid, that uses a storage battery, then again, using AC over DC would imply additional power conversions (gas-->AC-->DC-->AC-->mech vs. gas-->DC-->mech), which will also unnecessarily decrease your efficiency.

There's a reason most hybrids are DC.

RE: compareable motors.....ac vs dc

1 Horse Power = 0.746 kW

10 HP = 7.46kW

96VDC to 144VDC at 10HP is the same as 10HP AC motor.  All you need to do is pick a 10HP AC motor.  Judging from the voltage and the automotive topic, I would say you are putting this in an electric vehicle.  Pick an AC motor that is suitable for Inverter duty.  Look at Toshiba America website.  They should have some useful tips on selecting a motor.

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