[En-Nut-Discussion] 60Hz frequency measurment questions..

[James Lerch]

Greetings All,

I'm going to use my EtherNut board as a engine monitoring and control system for
my homebuilt 15KW generator project.  I think I've figured out how to monitor
everything except the line frequency of the generator output (60hz ideally).

While the generator has a mechanical governor on it, it tends to sag about 1hz
between no-load and 60% load (10KW).  One goal for the Ethernut board is to
operate a governor assist system to help keep the generator producing 60hz power
even under varying loads (else my UPSes all start getting upset).

The problem is I need to measure the frequency fairly accurately, preferably in
the +/- 0.1% range, and be able to update the difference between real frequency
and desired frequency fairly quickly. The diesel motor is a single
cylinder,running ideally at 1800rpm (15 power strokes per second, so I only get
to measure few cycles of output to calculate the mean frequency, in time to
update the throttle position in time for the next power stroke)

Any thoughts or suggestions?

Take Care,
James Lerch
http://lerch.no-ip.com/atm (My telescope construction,testing, and coating site)
http://lerch.no-ip.com/ChangFa_Gen (My 15KW generator project)

"Anything that can happen, will happen" -Stephen Pollock from:
"Particle Physics for Non-Physicists: A Tour of the Microcosmos"

" Press on: nothing in the world can take the place of perseverance.
Talent will not; nothing is more common than unsuccessful men with talent.
Genius will not; unrewarded genius is almost a proverb.
Education will not; the world is full of educated derelicts.
Persistence and determination alone are omnipotent. "
                                                           Calvin Coolidge