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PMOS Driver in 3-Phase Switch-Mode Inverter

I'm working on a motor drive for a 3 phase AC electric motor. I have a 48VDC supply. I am using six N-Channel mosfets to drive the three phase inverter that supplys power to the motor and Im using six P- Channel mosfets for regenerative braking (to act as a three phase rectifier). Are there P-Channel power mosfet drivers on the market? Everything I've seen as far as mosfet drivers go seem to be designed for N- Channel mosfets. Because P-channel mosfets require a 'negative' voltage on the gate I was hoping someone could direct me to a driver that could supply 2A (10V) to the gate of a PMOS for switching frequencies up to 1kHz. I know my description is quite brief so if you need any clarification message back.

Reply to
gregmhand
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On Nov 25, 5:48=EF=BF=BDam, " snipped-for-privacy@gmail.com" wrot= e:

ave

ee

Good so far.

and Im using six P-

WHY?? your existing mosfets will do the regenerating for you. You need to dump power from the dc bus into a resistor during braking. A little research will save you a lot of grief.

Reply to
cbarn24050

I have researched this a bit. If im trying to put energy back on the batteries dont I need P-Channel Mosfets to allow current to flow in the reverse direction? If you have any references on this subject that would help me I would greatly appreciate it.

-Greg

Reply to
gregmhand

No. MOSFETs allow current to flow in either direction (although they can normally only block current in one direction due to the intrinsic diode). H-bridge motor drivers often use this to perform synchronous rectification during freewheeling (the voltage drop across a fully-conducting MOSFET is often less than across a diode).

At the simplest level, regenerative braking just requires reversing the polarity. When driving the motor normally, you apply voltage so as to increase (or at least maintain) the motor current. If you reverse the polarity, apart from decreasing the current, the existing current will flow back into the battery.

There's some useful introductory material at:

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It deals primarily with DC motors (the author mainly uses modified auto starter motors), but much of it can also be applied to driving

3-phase motors.
Reply to
Nobody

For some pointers, see....

PerfectDiodeForChargerIsolation.pdf

on the S.E.D/Schematics page of my website.

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
|  Analog Innovations, Inc.                         |     et      |
|  Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
|  Phoenix, Arizona            Voice:(480)460-2350  |             |
|  E-mail Address at Website     Fax:(480)460-2142  |  Brass Rat  |
|       http://www.analog-innovations.com           |    1962     |
             
         America: Land of the Free, Because of the Brave
Reply to
Jim Thompson

On Nov 25, 5:26=EF=BF=BDpm, " snipped-for-privacy@gmail.com" wrot= e:

Not enough it would seem.

=EF=BF=BDIf im trying to put energy back on the

That will happen with just your existing 6 devices.

dont I need P-Channel Mosfets to allow current to flow in

No, research "inversion"

=EF=BF=BDIf you have any references on this subject

Too many to list, 5 mins with google should do it.

Reply to
cbarn24050

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