How does it work - inverter generators

Discussion in 'General Electronics Chat' started by theoldwizard, Mar 12, 2010.

  1. shortbus

    AAC Fanatic!

    Sep 30, 2009
    6,409
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    And how fast or far will that electric motor at zero RPM get you?
     
  2. Evanguy

    Member

    Dec 21, 2014
    81
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    i believe only steam engines can be producing max torque at 0 rpm.

    or a full voltage/amprage, STALLED electric motor would be also at full torque when at 0 rpm but rapidly over heating and burning up
     
    Last edited: Feb 27, 2016
  3. withoutego

    New Member

    Dec 22, 2015
    26
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    I do understand conversion loss and what seems obvious...ie energy is
    lost going from gas to electrical, 30% maybe?

    But, one of my considerations is that where I am Lithium ion batteries
    are hard to come by, the shipping. And SLA (sealed lead acid) are heavy.
    If I'm Using heavy SLA & not Lithium for 2KW the weight penalty is huge.
    2KW is only about 35 lb with some of these small generators.

    That's not much weight vs SLA of 2KW x 4 hours. The generator runs four hours,
    that's a capacity of 8 KWH. Not bad for 35 lb of overhead. Efficiency isn't always
    the deciding criteria. And, gas is subsidized here in Ecuador.

    Not trying to save the Earth, just to get up a hill. Maybe a 1500 Watt BLDC on a bicycle.

    But the balance tips If I have to do much to bring the power down to 72 or 96 Volts DC.

    Would a 1500 Watt BLDC motor tolerate PWM from a 180V DC source? in effect a
    buck converter with the windings of the motor the inductor(s). I suppose it would - if the
    controller were careful and also sensed the winding temperatures, keeping things inside
    the SOE (safe operating envelope). Thoughts?
     
  4. theoldwizard

    Thread Starter Member

    Jul 17, 2005
    19
    3
    Only if it STAYS stalled !

    Current will be several times the "rated" current. This is usually call LRA - "Locked Rotor Amperage".
     
  5. MaxHeadRoom

    Expert

    Jul 18, 2013
    17,746
    5,401
    If the motor is used in its Continuous torque range it can be stalled indefinably, it is when the maximum torque range is entered it can overheat if more than a short period.
    Motor specs, especially PM motors etc have a manufacturers spec showing the extent of each range and the Torque (current) figure for each.
    Max.
     
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