Can 50HP Motor be accelerated from 0 to full speed in 1 second?
Can 50HP Motor be accelerated from 0 to full speed in 1 second?
(OP)
Hello,
Can 50HP motor be accelerated in 1 second from zero to full speed?
And then decelerated in 1 second time?
This question may sound naïve but this is really what I need to figure out. The RPM value is not important as I learned.
The motor will be driving the pump and the pump is expected to provide some load. But even without load, is it physically possible to accelerate/decelerate 50HP motor in 1 sec?
The drive method: VFD, driving voltage assumed 220 - 500 V, assume infinite current supply available.
Can 50HP motor be accelerated in 1 second from zero to full speed?
And then decelerated in 1 second time?
This question may sound naïve but this is really what I need to figure out. The RPM value is not important as I learned.
The motor will be driving the pump and the pump is expected to provide some load. But even without load, is it physically possible to accelerate/decelerate 50HP motor in 1 sec?
The drive method: VFD, driving voltage assumed 220 - 500 V, assume infinite current supply available.





RE: Can 50HP Motor be accelerated from 0 to full speed in 1 second?
That said, you can assume, for lack of any other realistic information, that you size the VFD to be capable of providing Locked Rotor Current of the motor instantaneously (no point in sizing it any higher). LRC is typically defined as 600% of FLC, and VFDs are typically capable of delivering 150% of rated current. So if the VFD is sized as 400% of FLC of the motor, i.e. a 200HP VFD connected to a 50HP motor, then it is possible to accelerate an UNCOUPLED motor in less than 1 second for sure.
Now the other nasty little bit of reality sneaks in, the LOAD on the motor. The LOAD on the motor would be defined as the inertia of the pump itself, plus any additional torque required as the pump begins to pump. Without knowing what kind of pump we are discussing here and what you are puming (it is anhydrous amonia or peanut butter?), it's not possible to do any better than a slightly educated crap shoot. So to that definition within the above defined conditions, I say, ....
Maybe...
"Will work for (the memory of) salami"
RE: Can 50HP Motor be accelerated from 0 to full speed in 1 second?
Why do you want to accelerate and decelerate a pump in 1 second anyways?
RE: Can 50HP Motor be accelerated from 0 to full speed in 1 second?
Possibly to:
Create water hammer
Break a shaft or coupling
Waste energy
Dim the lights!
Walt
RE: Can 50HP Motor be accelerated from 0 to full speed in 1 second?
The motors I deal with, with DOL start, will be up to full speed in less than 1 second. This is with the load being a centrigugal pump and a stiff enough power supply that the voltage sag does not slow the start. It is with VFD and soft starts, which lengthen the motor start time, that can cause problems with the type of bearings we use. The stop time at load is not something we have concerned ourself with, as the systems our motors are in have other ways to immediately stop the pump output as the motors slows.
The size of motors we normally make are 5-350 Hp, with a few past 1000 Hp. However, our motors are a bit different than your standard electric motor, and the differences matter.
RE: Can 50HP Motor be accelerated from 0 to full speed in 1 second?
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Can 50HP Motor be accelerated from 0 to full speed in 1 second?
RE: Can 50HP Motor be accelerated from 0 to full speed in 1 second?
RE: Can 50HP Motor be accelerated from 0 to full speed in 1 second?
Basically you proved that my idea was possible however I did not win and system with hydraulic accumulator will be used to provide required hydraulic 'pulses'.
RE: Can 50HP Motor be accelerated from 0 to full speed in 1 second?