Post by thread:VFD DESIGN

Greetings: The application is 3 phase variable frequency ac induction motor drive using IR IGBT. After long reserach we came to a conclusion that the pic might not be the absolute choice for the above project, however we insist to develop the project with the PIC. My objective is to create a table which can generate: a)0.5 hz per step (240 steps equal to 120 Hz) b)1volt per step (240 steps equal to 240 V) c)Linear ratio V/F app equal to 2 as much as possible Has anybody done such an algorithm and implemented it using the PIC? I am very interested to cooperate? regards, Norayr S. Elmayan

Strongly consider using an IC such as the GEC/Plessey/Mitel SA828. It does ALL the hard work for you and is VERY CHEAP ($US4?) . You can still use a PIC to do the bells and whistles. ---------- > From: Norayr S. Elmayan <spam_OUTsesTakeThisOuTCYBERIA.NET.LB> > To: .....PICLISTKILLspam@spam@MITVMA.MIT.EDU > Subject: VFD DESIGN > Date: Wednesday, 15 July 1998 02:24 > > Greetings: > > The application is 3 phase variable frequency ac induction motor drive > using IR IGBT. > > After long reserach we came to a conclusion that the pic might not be the > absolute choice for the above project, however we insist to develop the > project with the PIC. > > My objective is to create a table which can generate: > > a)0.5 hz per step (240 steps equal to 120 Hz) > b)1volt per step (240 steps equal to 240 V) > c)Linear ratio V/F app equal to 2 as much as possible > > Has anybody done such an algorithm and implemented it using the PIC? I am > very > interested to cooperate? > > regards, > > Norayr S. Elmayan

I believe Linear Technology also has a new chip out for this. Don'thave the data sheet handy, but if interested, I'd like to discuss this. Also, an engineer at Microchip was working on doing this with a PIC, and I thought had a prototype working but lost contact with him (he may have left microchip).