how to create variable PWM in simulink

I working in type of motors with PWM and i want to control the duty of pwm in my modeling in simulink but i dont know what is the suitable function in the simulink to give me variable pwm ???

i hope help me soon

many thanks

Answer 1

[cr]

There is a built-in pwm block that varies dutycycle according to an input sine wave. See 2 and 3 level pwm generator blocks. If you need to vary dutycycle depending upon value of some signal, then the only way I can think of is by using s-functions to change the duty cycle at every step. There is a demo file in s-function demos. I have also described a simpler beginner-friendly version here: http://matlabtraining.com/blog/2013/10/how-to-write-s-functions/

Answer 2

[ahmed zaki]

Hi, actually i have technical problem in simulink: i select permanent magnet motor block with simulation setting(normal -ode45) the simulation couldn't continue and also give me alarm