Download AC 3-phase Induction motor

AC 3-phase Induction motor
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Findings of those 4 companies: Solectria, GE, Propulse, …etc can’t find the
motor model mention in the web that Dr. Lam send to us.
Find some GE AC motors (20hp or above), but the max. torque(58Nm) and
weight(300lbs) did not meet our requirement.
From Solectria, AC 42 is chosen. It can meet all the requirement of our EV
(MAZAD Demio).
Max. Torque
Imax
Cont. Power
Efficiency
rpm
weight
Dia/Length
AC42 (HK$21592)
150Nm
240A
21kw
93%
4000rpm
133lbs
9.75”/14.5”
Controller
voltage
Peak power
UMOC340
312V
65kw
Controller
voltage
Peak power
UMOC440(HK$46000)
312V
78kw
Too expensive
Ok
Ok
Ok
Heavier than DC
Ok
Too expensive
Good
Advantage:
1) AC motor can give out 40-50% more torque than DC motor ( But even the
torque given by DC motor is enough for driven Demio)
2)
By using AC controller, peak power given by AC motor can be more than 50kw
under 312V, that means the EV can have top speed up to 120km/hr or more.
( Top speed for DC series motor: approx. 100km/hr)
3)
Efficiency is 3-4% higher than DC series
Disadvantage:
1) AC system is about 3-5 times more expensive than DC system
controller (HK$40000-50000)
battery ( as it is about 312V  more batteries are needed (double the no. that
used in DC)  increase the cost and weight too
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You can input less voltage (use less battery) e.g. 144V, the peak power will sure
be less. For 144V, peak power is 36kw.  performance is the same as the DC
series  but controller cost more
2) AC motor is heavier. However, there is another model that has weight similar to
that of DC series, but the continuous power is not satisfied.
Max. Torque
Imax
Cont. Power
Efficiency
rpm
weight
Dia/Length
AC25
140Nm
240A
16kw
91%
3000rpm
104lbs
9.75”/13”
Controller
voltage
Peak power
UMOC340
312V
65kw
Controller
voltage
Peak power
UMOC440(HK$46000)
312V
78kw
Ok
Not enough
Ok
Ok
Ok
Too expensive
Good
Conclusion
AC motor is normally used for high performance EV, it can tell from the specification
that it really can do so, but it costs more. Once we change to AC system, costs will be
double or triple, then I suppose we target to make a very high performance EV:
Top speed = 100-120km/hr
Range = 125- 150 mile or more
Acceleration: 0-60 mph within 20s
Then, we need to use NiMH battery, in order to increase the range of the EV up to
150mile or more. We can’t just input 144V but must be up to 312V(26 modules 12V
batteries) so that we can get >50kw peak power to meet our top speed. As our system
is so super, our car can’t be so small. It must be large enough to place the 26 modules
12V battery and tough enough to support the increase weight.
As we have limited budget, I think it is better to use DC series motor. Its performance
is not as well as AC motor, but at least our EV can run and the cost is within our
budget.
For Demio, as the weight of the car increase, it affects the performance:
Total weight: 3500lbs
Top speed: 100km/hr
Normal speed: 40km/hr
Range: 75 mile (12 modules 12V battery)