Problems #8

 

1.     From the voltage and current equations develop the small signal model of a Switched reluctance Motor (SRM) drive. Also show the block diagram of the speed-controlled SRM drive.

 

2.     Derive the characteristic equation to design the current controller of an SRM drive and for a current controller with the following transfer function

 

 

Show how KCC and TCC may be found from the specified magnitudes of natural frequency and damping ratio.

 

3.     Design a current controller for an SRM drive with the following specifications for a bandwidth of 1600Hz and damping ratio of 0.707.

 

Motor & System Parameters:

Command signal levels:                  10V

DC Link voltage                            400V

Max. current                                  15A

PWM chopping frequency             8kHz

Phase resistance                            0.931ohm

Power                                           5hp

Rated current                                 10A

Rated speed                                  2500rpm

Friction constant                            0.001Nm/rad/s

Rotor inertia                                  0.006kgm2

Speed feedback gain                      0.0383V/rad/s

Speed feedback time constant        0.1s