how to give temperature setpoint to speed controller ?

hello friends. I need to control the speed of compressor to make the cabinet temperature to meet my set point temperature. I am confusing how to make my temperature error (cabinet temp - setpoint temp) to give as input to BLDC motor.

Thanks to the responds.

Answer 1

[Birdman]

You don't give temperature error to BLDC motor directly. You give it as an input to your controller and your controller will produce the desired voltage value for the BLDC motor.

[VAMSI KRISHNA THANIKANTI]

thank you for replay...Çevikalp Sütunç but the problem is I need to give the pid controller signal to a mathematical model of motor, not to a motor that available in simulink library.

[Birdman]

You have to obtain the mathematical model for the BLDC motor.

https://www.mathworks.com/matlabcentral/fileexchange/51069-dynamic--mathematical--modeling-of-brushless-dc-motor--trapezodial-back-emf-

Maybe this link will help.

[VAMSI KRISHNA THANIKANTI]

thank you Çevikalp Sütunç. hai how to convert the pid controller output into frequency that can supply to the motor

[Birdman]

You do not turn the control signal(output of the pid) into frequency. If your plant model is reliable, and your controller meets your design requirements, the control signal will automatically generate a voltage value which includes desired amplitude and frequency. You will just give a reference signal to the system and the rest will be done automatically.

[VAMSI KRISHNA THANIKANTI]

ok....... Thank you so much.

[Birdman]

If this answer is useful for you, then accept the answer so that other people having the same problem will know that there is a working solution.