Originally Posted by
SystemTheory
At this point when I plot a load line analysis on the extended line, I need to boost the start/stall current up to 110 Ampere to create equilibrium at the final speed of 2302{rad/s} with my red damping line passing through the torque-speed point at 7{s} and causing equilibrium at 10.3{s}. Then I get peak air gap power computed at 231{W} and bearing loss plus flywheel power adding up to 231{W}. I may sketch up the whole analysis tomorrow after I check my logic and calculations again.
This logic is incorrect. There is no requirement that the damping pass through the flywheel torque-speed point at 7{s}, or at any other point. Rather, accepting the 10 Amp current sensor measurement as accurate at the 2205 speed point, I then tweek the starting current upward and plot the air gap line in a graph until equilibrium occurs at 2302{rad/s} with this logic:
tweek start/stall current up from sampled 106 Amps to assume Is = 116 Amps:
k = Ts/Is = 0.385/116 = 0.003319{N-m/A} and/or {V-s/rad}
w0 = Vs/k = 8.4/0.003319 = 2531{rad/s} ideal speed if there were no friction
D = (k*10A)/2205 = 1.505E-05{N-m-s/rad}
At Is = 116 Amps the load lines and air gap line look right. This causes equilibrium at 2302{rad/s}, the flywheel peak remains 222{W}, the predicted spin up time is 10.33{s}. I need to look into the total air gap power at the peak flywheel power (now estimated around 241-243 Watts in the air gap).