One thing I would seriously consider is your choice of
MCU. I realize it's always easier to use something
that you're familiar with, but the MC9S08DZ60 is not a
motor control MCU. Since you're already familiar with
Freescale product, may want to consider something like
the DSP56F80x family of DSP's. They also have example
code already written for sensored BLDC control,
http://www.freescale.com/files/product/doc/AN1916.pdf?fpsp=1
You can get something running pretty quick using the
sample code and they also have low cost development
boards you can use before laying out your own circuit
board.
http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=ECMTREVAL&fpsp=1
I realize your just using the MCU to interface with
the UCC3626 BLDC control IC, but I think you may find
some limitations doing it this way. Overall I think
it's easier to start with a MCU/DSP that is intended
for motor control.
Good luck with either path you choose, and keep us up
to date on your progress.
Rod
MCU. I realize it's always easier to use something
that you're familiar with, but the MC9S08DZ60 is not a
motor control MCU. Since you're already familiar with
Freescale product, may want to consider something like
the DSP56F80x family of DSP's. They also have example
code already written for sensored BLDC control,
http://www.freescale.com/files/product/doc/AN1916.pdf?fpsp=1
You can get something running pretty quick using the
sample code and they also have low cost development
boards you can use before laying out your own circuit
board.
http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=ECMTREVAL&fpsp=1
I realize your just using the MCU to interface with
the UCC3626 BLDC control IC, but I think you may find
some limitations doing it this way. Overall I think
it's easier to start with a MCU/DSP that is intended
for motor control.
Good luck with either path you choose, and keep us up
to date on your progress.
Rod
--- Dale Ulan <[email protected]> wrote:
> >I'll take a look at what you're designing and
> >hopefully throw in some useful advice. I design
> BLDC
> >controls for my employer, Ametek, but these are low
> >voltage (24Vdc for most). I have designed AC
> inverter
>
> That's excellent. When I get my schematic done up
> I'll PDF it and put it on a web server. Overview -
> small microcontroller with CAN and 8 timers,
> MC9S08DZ60 or maybe a MC9S12XDP512. I use those
> for my ICE control already (my day job). Three
> timers do hall effect sampling, three timers do
> essentially a feed-through of the hall effect
> signal but with phase advance and direction control
> done in software - exactly like timing advance
> is done in ICE controls. Those outputs go to a
> UCC3626
> BLDC controller which does current control. The
> outputs of that go to either a IR21381 with
> booster transistors, or (my preferred method) a
> set of HCPL316's (also with booster transistors).
> Haven't decided yet. I like the simplicity of the
> IR21381 part but at these current levels, parasitics
> make me a bit nervous. Current sense will be via
> voltage drop across the bottom IGBT's. I will be
> flipping the high and low drive outs from the
> UCC3626 so the high side is chopped and the low
> side stays on so I can use the current sense method
> used in my Solectria BLDC's. At 300A, the voltage
> drop of my IGBT's are pretty constant regardless
> of temperature. In regen mode, I will be flipping
> the 4QUAD input to the UCC3626 so that the bridge
> operates in a boost mode.
>
> I got most of these ideas from looking at the
> shortcomings of my Solectria boxes. Mostly, they
> have odd control voltages, no redundant sensing
> on accelerator or brake input (so a failure can
> lead to full-on or full-brake), and no capacity
> to deal with a disconnected hall effect sensor
> signal gracefully. I want to address these before
> putting these in a vehicle - which I've got another
> potential glider to check out this weekend.
>
> I actually did work on the vehicle that these
> Solectrias came from - maybe 12 or 14 years ago.
> The controllers were weak, and that's why they
> were replaced with UQM motors and controllers.
> Too many repair jobs on the existing controllers.
> They had ESR issues on electrolytics, and
> insufficient
> voltage margin between bus and MOSFET ratings.
>
> -Dale
>
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