what is stand by mode of your FOC?

is the motor energised? if so, the stator provide the current to magnetise the machine, it can be up to 40% of the nominal current.

So even if it is not turning it is consuming current to impose the rotor flux

see : https://www.youtube.com/watch?v=drt2kUkALMQ&index=3

Basically, during standby mode of Flywheel, (Induction motor with inertia of 11) torque is zero but machine is still spinning at 15000 RPM. I think electromagnets in Induction machine shouldn't be supplied by stator currents? if I am not wrong?

but when command torque is zero there is still small electromagnetic torque generated within the motor which causes currents to flow on standby mode.

Any idea how to get rid of them?@ Lotfi Baghli

Dear Abid Soomro,

in Field Oriented Control the current components in d (direct) and q (quadrature) axes are controlled. The first component allows to produce rotor flux and the second is used for torque control. Since the induction machine has not any permanent magnets, it is necessary to produce the rotor flux using the electromagnetic induction phenomenon. To realize this task it is necessary to force current flow in the stator windings, which corresponds to the direct current component. In such a case even if the motor speed is zero, there is a stator current still present. Therefore I gues the FOC of induction machine works properly.

Best regards,

Lukasz Niewiara.

Dear Lukasz Niewiara,

Thanks alot for your informative answere. Yes, it makes sense when we relate this thing to the control system working principle. I think in order to get ride of these currents on stand by then inverter has to be switced off.

Thanks

Abid

Please allow me to ask wheter the system you are working on is a Simulation or an actual hardware prototype?

In general synchronuous reluctance machine have the lowest losses during idle in flywheel systems, so I am curious as to what made you choose the induction motor. I am guessing it was cost and availability.

I'd also be interestedin finding out more about your project, as this is my field of research as well. Are there any publications you can share yet?

Best, Armin