I am currently investigating the possibilities of implanting a flywheel energy storage system for demonstration but also being practically useful.

The flywheel I am intending on using is a steel disc with MOI of 1.22kgm^2

This would be connected to a Permanent Magnet (PM) DC machine via a flexible coupling.

I have selected two motors with desired torque speed characteristics, however each motor has a different rotor MOI.

1) Motor 1 = 0.00008kgm^2
2) Motor 2 = 0.0003 kgm^2

Obviously each of these have a very high inertia mismatch with the load. My question is this - what effect will either of these have on operation of the system (ie top speed, stability) and what could be done to optimize the performance?

Thank you,
Skyman

 

You will probably have difficulty tuning this system with such a large inertia mismatch and a flexible coupling. The load inertia will be in and out of phase with the motor due to the soft coupling and the motors control loop corrections. If you can run in an open loop velocity or torque mode, you may not have an issue. A typical digital drive controller will have a hard time. If you could rigidly couple your motor to the load, it would help greatly. I would also recommend running the motor in torque mode and closing the velocity loop externally in a computer or PLC. This way, you can make the loop as slow as you need.

Bill Sturm

 

Responding to Skyman's 10-Dec-09 (15:15) query...

Quite a bit of info was made available in the Control.com Thread # 956947997, of 2002.

Regards, Phil Corso

 

The another problem, except tuning of system with such very high mismatch, would be "regenerative" energy with deceleration of your flywheel. Than shunt regulator for power supply of motor amp is strongly recommended.