Three phase inverter from PWM

[callkalpa]

Hi,

I am developing a three phase inverter using PWM signals from a PIC (18F452). The PWM signal will be used to fire the IGBTs. For the three phase inverter I need three PWM signals each with a phase shift of 120 degrees to fire the three sets of IGBTs. It is possible to get one PWM signal with the PIC.

Is there a way by which (by programming the PIC or using some additional electronic devices) I can use a single PWM signal and get three PWM signals each with a 120 degree phase shift? Or do I have to use a PIC with three CCP modules?

Thanks in advance

 

[alec_t]

120 phase shift at what frequency?

 

[callkalpa]

50 Hz

 

[alec_t]

I don't see any way of getting the three PWMs from one CCP module. You could, of course, bit-bang three port pins in software to get the respective PWM outputs.

 

[Mr RB]

Have a look at the PIC 18F1230, it is designed with 3/6 PWM modules specifically for driving 3-phase applications.

https://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en022956