Author Topic: Arduino inverter load controller  (Read 13532 times)

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ontfarmer

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Re: Arduino inverter load controller
« Reply #30 on: June 13, 2016, 05:39:40 PM »
Have to get some parts  capacitors, solid state relay, and other things. Busy on the farm
now. Will be a few days before I get back to this.

Thanks





OperaHouse

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Re: Arduino inverter load controller
« Reply #31 on: June 15, 2016, 11:07:40 AM »

ontfarmer

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Re: Arduino inverter load controller
« Reply #32 on: June 15, 2016, 12:31:23 PM »
Thanks  OperaHouse   They are on there way! 



























would

ontfarmer

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Re: Arduino inverter load controller
« Reply #33 on: June 23, 2016, 05:24:29 AM »
Up date I have arduino uno,  9 volt wall wart.  Capacitors and relays are on order.

What else should i be getting?  Will  something be needed to cut the 135 volt from the panels

back for the uno?

Thanks

OperaHouse

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Re: Arduino inverter load controller
« Reply #34 on: June 30, 2016, 02:46:39 PM »
For other readers this project is a basic dump load controller that could be used on a
mill with slight modification. The same thing could be done with a GHURD controller.

I have to ask what what experience you have in electronics and equipment available.
Also, what parts stock do you have available?  Out town has electronics recycling and
I pick up an old UPS every chance I get.  Become friends with the dump guy, bring him
a bottle of Ripple wine.  Point is there is electronic waste everywhere.  An old plasma
TV has almost two dozen great FET to use in projects.

The 9V wall wart is fine for powering but it doesn't have enough voltage to  insure a FET
is driven into full saturation.  Keep looking till you find a 12V to 15V one.  You have
enough power to use two wall warts.  Placing a common 5V wall wart in series with the 9V
will supply enough voltage (14V) for the driver section.  Some of these are polarity
sensitive and will only work on one polarity when connected to the solar panel bus.  If
you find a higher voltage wall wart the voltage can be dropped to 9V with about 5 or more
diodes in series.  The input of the UNO will work fine with 12V input but the on board
regulator is small and tends to overheat with higher input voltage.  If a lot of stuff
is added an external 5V regulator should supply that.

The standard software of the UNO has a PWM of 490Hz.  Such low speeds are very forgiving.
I use opto isolators to drive the FET.  They are slow, the turn off speed is about four
times slower that the turn on. The transitions are often the biggest source of FET heating.
When operating at 20KHz and higher these transitions are critical, not at 490Hz.  A lot of
people want to use a real FET driver so they look professional. If you are not very experienced
these driver chips can get you in a pack of trouble.

Have you settled on a FET yet?  Select one with at least 250V and plan on using three in parallel
with them being at least 15A each.  Tried any programming yet on the UNO?  When you get to making the capacitor bank, make it simple to disconnect about 5 caps at a time so a shorted cap can be found easily.  You should start your own thread to document the project.
« Last Edit: June 30, 2016, 02:53:01 PM by OperaHouse »

ontfarmer

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Re: Arduino inverter load controller
« Reply #35 on: July 02, 2016, 04:04:04 PM »
   I have very little knowledge on electronics. Have a lot of knowledge on mechanical,
 electrical, hydraulics, pesticides. Learned quit a bit ( for me ) recently studying electronics.

I have equipment and experience with ( some guidance ) to put this together.

Have local recycling on electronics, a bit in surplus stores, most has to be ordered.

Might be able to get fets from a TV ?

Read the programing of the UNO but have not done it, Received the capacitors and soldered  them in groups of five.



Mary B

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Re: Arduino inverter load controller
« Reply #36 on: July 03, 2016, 07:32:09 PM »
Be very very careful of that capacitor bank! You have enough instantaneous current to melt those wires if they short!

OperaHouse

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Re: Arduino inverter load controller
« Reply #37 on: July 05, 2016, 09:40:12 AM »
It can pack a wallop.  I suggest initial testing only be done with one bank of capacitors.  The bank will be at a fixed voltage, peak current will always be the same.  Only the pulse width will change and the average power.  For this reason the power module should be placed as close to the load as possible.  Since it is opto isolated, the micro controller can be placed 100 feet away from the power module with no problem.  The wall warts can also be placed at this location with cheap telephone cable bringing the signals to the micro.  It is a good idea to connect the high voltage sense lead through a 47K or higher resistor.  That will become part of the voltage divider and prevent any cable short from burning up a light cable wire.  These are lethal voltages so protection against touch should be implemented.  A bleed resistor, around 300K, should be included to discharge the capacitor bank when the system is off.

A new thread should be created rather than hijacking this one.  I'd like to hear what Rich is presently doing with the system.   When you get down to about 30V with those SMPS power supplies some extra voltage margin can be gained by shorting out the diode and the resistors (for EMI filtering) in series to the main cap.  These can often add up to more than a dozen ohms.  Two to three volts can often be gained which is a lot at 30V.
« Last Edit: July 05, 2016, 04:26:57 PM by OperaHouse »

ontfarmer

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Re: Arduino inverter load controller
« Reply #38 on: July 05, 2016, 05:56:11 PM »
Richhagen   Sorry got carried away with my own personal project
on your thread.

My Apology