Is there an ideal sample time or rule of thumb for simulating discrete time motor models with field oriented control?
I've been working on a Motor Control Project, controlling a Stepper Motor with field oriented control. I oriented my model towards the motor control blockset. The Stepper Motor is a block build by myself (discrete time). My Current Control loop is working with 16kHz. My Motor is simulated every 160kHz, so 10 times faster, as the control loop (The factor of 10 is used in some motor control blockset examples). With the goal to get faster simulation results, i tried to reduce the sample time of my motor model. The strange thing is, that i've got different control behaviour. Here are some pictures of my motor speed response (speed is ramped) with different motor sample times.
Motor Sample Time: 160kHz (10 times faster than current control)
Motor Sample Time: 80kHz (5 times faster than current control)
Motor Sample Time: 32kHz (2 times faster than current control)