RussellMc
2018-09-19 14:40:52 UTC
Extremely useful 34 page manual on using Fisher & Paykel "smart drive" BLDC
motors as BLDC motors - not quite so trivial as it might seem :-).
The NZ originated F&P direct drive motors are available in surplus washing
machines and other domestic equipment in a number of countries worldwide -
USA included. I recently encountered one in an LG washing machine so they
may be even more widespread in other than F&P machines.
These motors are widely used as wind turbine and water-power alternators
and somewhat less widely used as motors for ebikes, and other applications
that will benefit from high torque low RPM direct drive motors.
Applications could include lathes, potting wheels (example given in
manual), gate openers, ... numerous position and variable speed control
applications.
This manual explains the various versions liable to be encountered in
surplus equipment and how they can be driven using off the shelf brushless
motor controllers. A far better treatment than usually encountered.
Their results seem to be "somewhat empirically biased" (a la Edison) but
still useful.
https://drive.google.com/file/d/0BzVDBix3S_qbNU1YWmZwTUFsQ2s/view
Not mentioned in the manual (I think) is the fact that the motors can be
rewired from having coils highly serial connected to series-parallel or all
parallel arrangements (per phase) allowing lower voltage higher current
applications.
As supplied the motors use ferrite magnets (a cost / performance tradeoff
decision) and produce outputs typical;ly in the 300 - 1200 Watt range. .
Conversions to neodymium magnets produce powers in the 2 to 3 kW range and
attendant cooling challenges. The table on page 10 allows power outputs to
be assessed.
Power ~= nm/10 x RPM.
So 29 nM at 460 RPM =~ 1300 Watts
The 1200 RPM, 24 nm claim is suspect but may be true = 2880 Watts !!!
Section 4.5 on page 12 suggests rather less power (as expected).
motors as BLDC motors - not quite so trivial as it might seem :-).
The NZ originated F&P direct drive motors are available in surplus washing
machines and other domestic equipment in a number of countries worldwide -
USA included. I recently encountered one in an LG washing machine so they
may be even more widespread in other than F&P machines.
These motors are widely used as wind turbine and water-power alternators
and somewhat less widely used as motors for ebikes, and other applications
that will benefit from high torque low RPM direct drive motors.
Applications could include lathes, potting wheels (example given in
manual), gate openers, ... numerous position and variable speed control
applications.
This manual explains the various versions liable to be encountered in
surplus equipment and how they can be driven using off the shelf brushless
motor controllers. A far better treatment than usually encountered.
Their results seem to be "somewhat empirically biased" (a la Edison) but
still useful.
https://drive.google.com/file/d/0BzVDBix3S_qbNU1YWmZwTUFsQ2s/view
Not mentioned in the manual (I think) is the fact that the motors can be
rewired from having coils highly serial connected to series-parallel or all
parallel arrangements (per phase) allowing lower voltage higher current
applications.
As supplied the motors use ferrite magnets (a cost / performance tradeoff
decision) and produce outputs typical;ly in the 300 - 1200 Watt range. .
Conversions to neodymium magnets produce powers in the 2 to 3 kW range and
attendant cooling challenges. The table on page 10 allows power outputs to
be assessed.
Power ~= nm/10 x RPM.
So 29 nM at 460 RPM =~ 1300 Watts
The 1200 RPM, 24 nm claim is suspect but may be true = 2880 Watts !!!
Section 4.5 on page 12 suggests rather less power (as expected).
--
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist