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原帖由 爱模英雄 于 2010-2-24 17:58 发表 
。。。。。。例如用KV值一样但大小不一样的电机又应如何配？
很想知道，不胜感激啊。。。
这里没法上PDF文件，我这里有份英文的，内容我贴出来仔细看看，可能有帮助
Brushless Motors
What you need to know.
January 2008 Wayne Rademacher
Motor selection info.
Watts per pound of airplane weight.
n 100w/lbs = trainer/sport
n 150w/lbs = 3D aerobatics
n 200w/lbs = extreme
Watts = volts * current
n 7.4v * 10amps = 74watts
n 11.1v * 25amps = 277watts
n 22v * 50amps = 1110watts
Ex. 16oz sport airplane = 100w motor
746watts = 1 horse power
January 2008 Wayne Rademacher
Motor formulas
Efficiency: Motor Efficiency = Pout/Pin, Pout = (Vin - Iin * Rm) * (Iin - Io)
Motor Kv: Kv = RPM / (Vin - Vloss), Vloss = Iin * Rm
Motor RPM: RPM = Kv * (V - Vloss), Vloss = Iin * Rm
Watts: Watts = V * Iin, Alternately P=I2R (P = I x I x Rm)
Stalled Motor: Istall = Vin / Rm
Torque constant: Torque constant: Kt=Kb x 1.345, Kb = Voltage constant (Volt/1000
RPM)
Torque Loss: Torque = Kt * (Iin - Io)
Termination: Wye = the number of winds you have performed, Delta = divide the
number of turns by 1.73
Watts per Horsepower: 1 horsepower = 746 watts
Kv-Rpm constant: Kv * turns = motor constant, (ex. Kv=1090 * 32T ~= 35000 so,
35000/28T ~= 1250Kv)
January 2008 Wayne Rademacher
Motor formulas - Acronyms
Acronyms:
Rm = Resistance value of the motor, derived from the guage of wire used.
Pout = Power Out of the Motor expressed in Watts
Pin = Power In of the Motor expressed in Watts
Vin = Voltage Into the Motor
Iin = Current Into the Motor
Io = Noload Current of the Motor, derived from running a motor WOT without a prop
at varying voltages. Io can be expressed with an associated Voltage and should be.
Kv = K value or voltage constant, the expressed value where the rpm can be surmised
by a given voltage. For a 2000 Kv motor an input voltage of 10V would net
20000RPM.
Istall = The load current of a motor which is purposely stalled, hence not turning.
Kt = Torque constant (oz-In/A)
Kb = Voltage constant (Volt/1000 RPM)
January 2008 Wayne Rademacher
Misc. motor info.
PI*(dia./2)^2) = sectional area of wire
~ Delta > Star = .578 (.562 - .526)
~ Star > Delta = 1.73 (1.78 - 1.9)
Doubling the number of winds halves Kv (rpm/volt) and doubles Kt (torque/Ampere),
Doubling stator height halves Kv, doubles Kt and (roughly) doubles maximum power.
Kv-Rpm Constant:
Example:
The 3008-32 motor has a Kv of 1090. If you take 1090 x 32 you get 34,880. If you look at the
3008-28 motor, it has a Kv of 1253.
If you take 1253 x 28 you get 35,084. Based on these 2 numbers, you can see that the constant
for the 3008 size motor is right arounf 35,000.
If you take 35,000 and divie that by the number of turns, you will get the approximate Kv of the
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发表于 2010-9-9 21:46
