If you need assistance, please send an email to forum at 4hv dot org. To ensure your email is not marked as spam, please include the phrase "4hv help" in the subject line. You can also find assistance via IRC, at irc.shadowworld.net, room #hvcomm.
Support 4hv.org!
Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.
Special Thanks To:
Aaron Holmes
Aaron Wheeler
Adam Horden
Alan Scrimgeour
Andre
Andrew Haynes
Anonymous000
asabase
Austin Weil
barney
Barry
Bert Hickman
Bill Kukowski
Blitzorn
Brandon Paradelas
Bruce Bowling
BubeeMike
Byong Park
Cesiumsponge
Chris F.
Chris Hooper
Corey Worthington
Derek Woodroffe
Dalus
Dan Strother
Daniel Davis
Daniel Uhrenholt
datasheetarchive
Dave Billington
Dave Marshall
David F.
Dennis Rogers
drelectrix
Dr. John Gudenas
Dr. Spark
E.TexasTesla
eastvoltresearch
Eirik Taylor
Erik Dyakov
Erlend^SE
Finn Hammer
Firebug24k
GalliumMan
Gary Peterson
George Slade
GhostNull
Gordon Mcknight
Graham Armitage
Grant
GreySoul
Henry H
IamSmooth
In memory of Leo Powning
Jacob Cash
James Howells
James Pawson
Jeff Greenfield
Jeff Thomas
Jesse Frost
Jim Mitchell
jlr134
Joe Mastroianni
John Forcina
John Oberg
John Willcutt
Jon Newcomb
klugesmith
Leslie Wright
Lutz Hoffman
Mads Barnkob
Martin King
Mats Karlsson
Matt Gibson
Matthew Guidry
mbd
Michael D'Angelo
Mikkel
mileswaldron
mister_rf
Neil Foster
Nick de Smith
Nick Soroka
nicklenorp
Nik
Norman Stanley
Patrick Coleman
Paul Brodie
Paul Jordan
Paul Montgomery
Ped
Peter Krogen
Peter Terren
PhilGood
Richard Feldman
Robert Bush
Royce Bailey
Scott Fusare
Scott Newman
smiffy
Stella
Steven Busic
Steve Conner
Steve Jones
Steve Ward
Sulaiman
Thomas Coyle
Thomas A. Wallace
Thomas W
Timo
Torch
Ulf Jonsson
vasil
Vaxian
vladi mazzilli
wastehl
Weston
William Kim
William N.
William Stehl
Wesley Venis
The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.
Registered Member #103
Joined: Thu Feb 09 2006, 08:16PM
Location: Derby, UK
Posts: 845
I suppose in terms of PID control it is 'integral only'.
I have a 10mS control loop in software, and every time the 10mS loop runs I take the latest ADC reading, and calculate the error. The error then gets added to the cumulative error, and then every 100mS I look to see if the error is positive or negative by a certain amount - and increment or decrement the duty cycle by a fixed amount if it is. It's a fairly simple way of doing it, and has a fairly sluggish response - but that's all that's needed because the system (solar panel and large battery) has a large time constant anyway.
To actually generate the PWM I am using an Atmel AVR, and using it's built in PWM generation (capture/compare unit on other micros).
Registered Member #190
Joined: Fri Feb 17 2006, 12:00AM
Location:
Posts: 1567
I see. The problem is the "sluggish response" part. If I wanted to implement a design for a wind turbine the response has to be rapid. In this scenario, if the voltage exceeds a certain value the inverter can blow. The voltage on a solar system is usually fixed.
Registered Member #103
Joined: Thu Feb 09 2006, 08:16PM
Location: Derby, UK
Posts: 845
the sluggish response is only in the 100's of milliseconds, so I think you'd still be ok. If not, adding some proportional would help, or full-on PID control would be another way forward, but tuning would be tricky.
So the wind turbine is rectified into a grid tied inverter? I have an 'overvoltage disconnect' on my solar system, whereby if the 'voltage clamp' cannot clamp the input from the solar for some reason (i.e. dumpload disconnected) then a relay is held open. You'd probably want something similar, in the form of 2 relays shorting all the phases together for say 10 seconds?
Registered Member #190
Joined: Fri Feb 17 2006, 12:00AM
Location:
Posts: 1567
I have physical shorting switches and disconnects. The linear shunt controller will control the turbine speed if I lose the grid or the voltage gets too high. There are other protective mechanisms to ensure that the voltage does not get near the inverter maximum input voltage.
I am curious about the switching shunt controller just for the sake of learning about a different approach to my linear solution (with the help of Dr. Slack and others on this board).
This site is powered by e107, which is released under the GNU GPL License. All work on this site, except where otherwise noted, is licensed under a Creative Commons Attribution-ShareAlike 2.5 License. By submitting any information to this site, you agree that anything submitted will be so licensed. Please read our Disclaimer and Policies page for information on your rights and responsibilities regarding this site.
mosfets in linear and switch mode
