Re: VSD Control Platform

Gary Pace wrote:

> Hi,
> I'm about to design the hardware for a new variable speed drive
> controller. Since I'm largely targeting high power systems, I certainly
> don't need to squeeze the last buck out of the controller.
> I am looking for processing power (determinism is very important so I
> think I need to steer away from "lighting fast from cache, dog slow
> otherwise" processors)
> Easy design cycle is also very important

You didn't indicate the type of motor drive you were looking at but I will
assume 3 phase motor from a 6-switch bridge. When you say high power are we
speaking in kW or MW ranges?.

> I am a bit out of date on CPU's DSP's etc that are currently widely used,
> so if anyone has a better idea I'd be grateful to hear it.

There are some chips that deal with the complete full vector control of
bridge based drives for three phase motors. These can be interfaced to some
quite simple processors and provide adequate performance. If you prefer not
to be locked into these chips then there are a whole host of processors out
there that have the capability to perform well in such tasks.

If you are just in need of speed and/or torque control then a full vector
controller could even be created in FPGA incorporating a processor core,
some memory and the necessary interlocking logic (to prevent shorting the
psu through two devices down a chain) for the drives and is readily
achievable from freely available core IP.

Before I point you in any specific direction though, perhaps you would care
to reveal some more requirements for these drives that would enable us to
get a better taset of what you are specifically after in the outcome of the

Paul E. Bennett ....................<email://peb@xxxxxxxxxxxxxxxxxx>
Forth based HIDECS Consultancy .....<>
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