Sunday, August 4, 2013

Arduino based DC Generator controller and Alternator Regulator - finished?

Well, today is kind of a milestone.   Today I posted what might become the 1st 'final' release of source for my integrated DC Generator and Alternator Regulator project, the automation project that gave me a nice push-the-button remote control for our Kubota based DC Generator and Watermaker.

What is so special about today?  Over the past few weeks I have been exercising the last part of this controller, namely the ability to manage the watermaker's high pressure pump in conjunction with the alternator.   Previously (when I was using a common 'smart' regulator, one that comes in a Blue heatsink) I would need to turn off the alternator when running the watermaker, the poor little Kubota just did not have enough horsepower to run both at the same time, and the 'smart' regulator did not have sufficient flexibility to adjust things.

Well, that is not the case anymore.

Now when I press the 'Watermaker' button, not only will the High Pressure pump for the Watermaker start up, but the output of the Alternator is scaled way back to account for the power needed to drive the pump.  After a few runs I have settled on scaling the alternator back to around 50A.    So, the 2nd major goal of the project is completed - I can put a small amount of power to put back into the batteries WHILE running the Watermaker.

And today I finished with the tweaks and small bug fixes to allow smooth transition into and out of Watermaker mode.

I am really happy with the outcome of this project.  I am able to maximize the Kubota's usage while it is running, shortening overall recharge time, co-generate while powering the Reverse Osmosis watermaker, have the engine speed adjust down to an idle as the battery becomes charged, and then auto-stop the generator when the battery is full.  Monitor all from a nice remote display and know the controler is also looking out for faults like oil pressure, raw water flow, overheating, etc.  Not only that, but we have noticed that with the unit slowing down towards an idle as the battery gets fully charged (and the demand on the alternator is reduced), we now tend to just let the generator keep running - finishing off the battery charging (as opposed to stopping things when they batteries got to say 85% charged).   Over the long run I am sure the batteries will be much happier - and this is really a bonus as I had not 'planned' on this going into the project!

This fall I will be adding simple monitoring of critical pressures in the Watermaker: the pre-filter boost pump, and the High pressure pump.  Currently I have to check the watermaker every 10-20 minutes to make sure those are still at their targets, adjusting as needed.  I want the controller to watch these critical pressures and alert me when they start to stray out of bounds, and then shut things down if they get to a place where damage can be done to some part of the system.   Not sure I will go beyond that (ala, full automation of the Watermaker); at least not for now.  But I do want to add in the safety monitoring capability.

But unless something major comes up for now it is 'done'.

And if anyone is indeed interested in this, check out the blog where I have documented all  (Everything is available for non-commercial use at no charge), and if someone is really interested: I do still have a blank PCB left over from the manufacturing runs.

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