motor - What is the output of a PID controller (or any controller in general)?

I'm new to Simulink and I'm trying to get my hands a little dirty there to get used to using it. I'm working on a speed control of a switched reluctance motor. The input signal is to be fed to a converter (IGBT's gate) to control the speed of the motor.

Consider the general diagram below:

So my controller is a PID , my input is the reference speed of motor , my output is the measured (actual speed) of the motor and the plant is the "converter-motor" set up.

(1) What is the actuating signal obtained from the controller? Is it the control signal to be fed to the IGBTs?

(2) What if the plant input is a voltage (we are directly feeding voltage to the terminals of the motor). Isn't the PID output pretty much the same as the case of IGBTs? The Simulink controller produces a control signal how should I use it to feed voltage instead ?

Thanks ahead

Answer

What is the actuating signal obtained from the controller?

It is usually an analog signal like 0 to 10 volts with 20 mA maximum load current or 4 to 20 mA with 24 volts maximum load voltage.

Is it the control signal to be fed to the IGBTs?

No. For a switched reluctance motor, The IGBTs would be fed gate signals that would have a timing sequence determined by the reluctance motor controller. That controller could receive an analog input signal from a PID controller.

What if the plant input is a voltage (we are directly feeding voltage to the terminals of the motor).

A DC motor with a commutator could be fed voltage directly. In that case, there would be a control amplifier between the PID controller and the motor. The amplifier simply converts the output of the PID controller to a higher voltage and current.

The Simulink controller produces a control signal how should I use it to feed voltage instead?

You would need to add a power amplifier between the PID and motor.