Newbie help with bike axial flux generator

[hiker]

Ceramic mags always need to be cleaned before gluing down,,not sure on the Nickle coated mags,,,,,

[HomeBrewer]

Hello everyone,  A completely different dimension is how does one connect said exercise bike with axial flux alternator to a grid tie and meet NEC codes.  I was looking at the power-one micro inverters and then called them.  The guy said each one of their UL certifications costs about 70-80k USD and designed for PV only so from their perspective connecting to that will not meet NEC code.  There is a company called sportsart that is making the equipment and it is "grid tied". 

http://gosportsart.com/en/cardio/eco-powr/

  I called the North American rep and asked how it may be UL listed but no knowledge in that area other than it "plugs into the wall" and is UL listed.  So, I wonder if the only universal way to go about it would be to use a charge controller acceptable for a wind application with a battery bank.  The Xantrex have the ability to charge NiCad but do not advertise for battery chemistries such as NiMH.  It would be ideal to be able to get around the UL listing requirements by using already existing technology.  Ideally, if a battery system is an absolute must, then something that can be used on a small scale would be ideal.  Any suggestions and/or wisdom on how the bicycle generator would be grid tied and meet NEC code would be invaluable. I would like to avoid batteries if possible.   Best regards, Mike

[HomeBrewer]

Hello everyone,  I know low voltages mean a lot more loss in the diodes.  A couple thoughts, being that this is in the couple hundred watt range but targeted sustained 100w range I wonder if Schottky diodes would lower losses and along that line if the previously posted sportsart equipment is able to state UL listing because everything is contained inside the same plastic container and/or if they are using some low voltage scheme such as 12vdc unregulated that may be considered a "safe voltage" for UL purposes going into the grid tie inverter?  If I remember correctly 24v PV arrays do not require conduit because of the lower voltages for example.  Best regards, Mike

[HomeBrewer]

Hello everyone,  A couple things noted after researching.  No NEC code allows direct plug in of grid tie inverter into a wall outlet from what I've read it falls into a "gorilla power inverter" area like they had on that home power magazine back in the 90's.  People do it but if your house has a smart meter it could be detected and it defaults out your fire insurance.  Codes vary by state depending on where you can interconnect the grid tie with disconnect switches etc.  It seems that the only way to go about it may be either micro inverters that follow the local and NEC codes for where they are connected but that problem again arises in possibly violating the UL listing of the inverter by not using PV.  Or, using charge controllers into a battery bank via a UL listed charger and subsequent UL/NEC compliant grid tie.  This is an area I am not familiar with how to accomplish.  Anyone using hyrdro must be off grid it seems as there seems to be nothing on that subject of tying it into the grid.  Best regards, Mike

[joestue]

so the smart meters have a quadrature led and ir detector that watches the meter move.. and round here there are only two flags on the meter.

so if you build a program to monitor the power backfeeding the grid and make sure that you turn off your grid tie before 2 watt hours backfeeds into the grid, then you can't trip the system.

if you're that paranoid, dump the power into a car battery and run your microwave off an inverter.. i guarantee you won't keep that battery charged lol..

[HomeBrewer]

Hi joestue,

  Very cool,  I have been working with electronics for 33 years as a tech and had to look that up.  I saw a quadrature encoder used with stepper motors.

  I was looking at possibly using the following hardware with the stator wired for 3phase 30 volts at 100w output while pedaling in the 70-90rpm range.  Saw alot of really good reviews for the Renogy Tracer 100v max input charge controller then realized Tracer is it's own brand and it has a 150v max input 20a unit as well which autosenses 12/24v batteries and according to the reviews is a true MPPT and not a fake one.  Cost is in the 100-150 range dependant on the 2215rn or 2215bn

http://www.amazon.com/EPsolar-Tracer-Battery-Controller-Regulator/dp/B00N1QG3M4/ref=pd_sim_sbs_147_5?ie=UTF8&refRID=1ZXZA7P6PJHBKFY0PM20

http://www.amazon.com/EPsolar-Tracer-Battery-Controller-Regulator/dp/B00N1QG3M4/ref=pd_sim_sbs_147_5?ie=UTF8&refRID=1ZXZA7P6PJHBKFY0PM20

The grid tie inverter I am looking at using is the power-one (abb aurora) 300w model, about $225,  It can take only up to a 60v/75v input depending on model but has US 240 split phase as well as Philippine 220 single phase capability.   

http://www.thepowerstore.com/photos/pdf/MICRO-0.25-0.3-0.3HV-Rev1.3.pdf

  This would give battery charging or grid tie but there is a bit of a problem in that the power one would likely suck down the battery voltage when not pedaling.  I have always wondered if it would be possible to replace the battery with a bank of capacitors (i know the energy storage in the caps is very little) in order to allow the charge controller to be happy thinking it is charging a battery.  It would be necessary to have a current limiting capability (like inrush current limiting on tube amps).  If the capacitor bank was on the input of the grid tie inverter with a switched output from the charge controller then possibly the bike could either be connected to charge 12/24v batteries or the batteries switched out with the small capacitor bank switched in for purely grid tie making it very versatile.  UL listing would be out the door at this point or would it being the charge controller I am assuming is listed as well as the grid tie inverter.  There would be details involved but do not see why this cannot be done.

Best regards,
Mike

[dnix71]

Homebrewer You are correct about plugin gridtie. If someone told you that the device has a UL cert and is a US market plugin gridtie inverter, you should go here: http://ul.com/offerings/manufacturers/global-security-brand-protection/contact-ul-gsbp/ and report it.

UL would not certify anything that is forbidden under the NEC. The reason for forbidding a plugin gridtie are:

1. The meter would have to be changed for your backfeed to register properly. Modern meters cannot run backwards to prevent someone from flipping the meter over to get free electricity as was possible in the past. You either get a one-way meter (asymetric) or you have a proper grid-tie meter installed after the installation has been inspected. If you force an asymetric meter to run backwards you will be charged for the electricity going out to the grid and the meter will set a flag that indicates you tampered with it.

2. The power company wants to know where a potential backfeed to the grid is, so if the need to work on the lines or transformers, they can lock out and isolate the gridtie to protect their lineman. Gridtie inverters are not supposed to backfeed if the grid is down, but smart people don't take chances.

3. A plugin inverter is a safety hazard in more than one way.

A. Consider the cord used. Most of the illegal gridtie inverters I have seen use a common computer/appliance cord. Those cords come in different lengths and wire gauge, but they are all physically interchangeable. How would you insure that the cord you choose can handle the load?

B. Where are you plugging the portable inverter in? An outlet somewhere. Most likely an outlet on a branch circuit. You are not backfeeding the grid as much as you are backfeeding a branch somewhere in your home's electrical system.

C. Most new home come with ground fault circuit interrupters. GFCI's have a "line" and "load" side. If you have one at the service panel and try to backfeed a branch out you will smoke the panel GFCI. Big bucks to replace. If you try to backfeed an individual GFCI it will fail. If you remove an individual GFCI to backfeed that branch you will have no line fault protection on that branch.

D.Proper gridtie inverters backfeed symetrically. In the US we have split phase 240 for residential service. The transformer on the pole is center tapped to ground and the center tap is also the neutral. Each half of the transformer feeds 120 to one side or the other of your service panel. Use one side hot and you have 120v, use both hot wires and NO neutral and you have 240v. If you backfeed with a plugin 120v inverter you can only feed one half of the transformer. Also the only place the ground and neutral are bonded is at the pole and at the panel. Your 120v inverter won't work properly plugged in a branch because there are stray currents and voltage present on branch circuits from less than perfect power factors of appliances. A gridtie inverter installed at the panel will see a clean ground and neutral because they are bonded there and your panel is earthed there.

[HomeBrewer]

Hi dnix71,

  You made an interesting point when you discussed the 240 split phase in USA which I was aware of.  In the Philippines if you look on the internet it is 220vac 60hz single phase with one leg tied to ground.  But at my houses here it is split phase and measured 236vac with one leg at around 112 and the other around 114.  I can tie my outback GTFX2500 inverters in classic series without need for a custom transformer as originally thought.  Next Thursday I have a meeting with the Bureau of Investment, BOI, with a representative from the Philippine DOE to achieve a tax free status for producing alternators.  Tax free will be for import/export and a fixed 5% VAT for national sales which is a really big deal in cutting the costs.  The axial flux alternators could be used in spin bikes and even wind turbines of course.  I think the only way a spin bike would be successful would be to be part of an existing grid tie residential solar and/or wind or in a commercial gym.
  The question becomes if I use a grid tie off an axial flux alternator how would it pass inspection?  If I follow the rules of the road with a disconnect and tied into the correct place will I have problems with my grid tie inverter without the use of a charge controller off the axial flux alternator?  I would think common sense should prevail but that always is not the case. The Ginlong will take 50-400v for their 700 watt model (overkill) and could work off the 90v stator (at 100 watts).  Using a charge controller that goes up to 150vdc like the one previously mentioned could allow a fixed voltage range into the grid tie but if one would want to eliminate use of a battery bank I wonder if a capacitor bank could trick the charge controller into being happy thinking it is going into a battery?    Best regards, Mike

[dnix71]

An adult can make about 100 watts for an extended time pedalling on a bicycle. If you need to run your grid by pedalling bicycles, then you have bigger issues than I can help you with.

For the same money solar will run the grid during the day. Charge some batteries and you can run lights or small appliances at night.

Grid tieing a pedal generator won't work well anyway. Gridtie inverters have a lock out period of 5 minutes and up waiting for a stable input, and much longer for stability on the output side. You will find it difficult to pedal correctly long enough for the inverter to see stability and sync with the grid to backfeed (unless you have a rechargable battery between the pedal gen and the inverter.)

[HomeBrewer]

Hi dnix71,

  Interesting point regarding the lockout period of time.  But there are wind turbines that are grid tied and I am discussing the use of AFPMG's so it may be done.  The current intention is to use PMW vice MPPT and a Xantrex C series to get that accomplished.  Between the PWM charge controller and grid tie I was considering either a battery or a capacitor bank as there is not a real need for huge amounts of storage.  The intention is not to replace large amounts of electricity but to provide small amounts of power during an exercise period.  For emergency small generation it would be useful but for everyday exercise it cannot hurt to make small amounts of power.  It would be interesting to see the different lockout times for different inverters as that does not appear to be a commonly published spec.  I was looking at either the enphase m250, power-one aurora abb 300w, or the 700w gin long.  Best regards, Mike

Best regards, Mike

[HomeBrewer]

Hi dnix71,

  I have two Outback 2500w sealed GTFX series with disconnects on the AC and DC side.  I see a matter of seconds before the AC output begins when the disconnects are turned to an on position when non-grid tied.  Are you talking about a 5 minute delay on the grid side as I see very little delay on the DC side before an AC waveform begins.  I am applying for net metering at this time so the grid tie has not been enabled yet.

Best regards,
Mike

[dnix71]

HomeBrewer If you internet search there seems to be some kind of regulatory requirement for at least a 5 minute lock out if grid instability is detected. The lockout can get much longer if there are several disconnects in a row. In places with an unstable grid, this ruins the economies of grid tying.

http://forums.mikeholt.com/showthread.php?t=166884  Talks about that kind of lockout as well as the troubles getting direct ac coupled and battery systems to play nice with each other.

[Mary B]

Now that is good to know! Grid here is a joke so I would be offline more than on! Neighbors AC kicks in my voltage drops to 100 volts... that transformer on the pole both houses share is older than I am...

[dnix71]

Mary B buy your neighbor a boost cap for their a/c. $40 for a kit big enough for a whole house ac.
http://www.ebay.com/itm/Compressor-Saver-Hard-Start-Capacitor-3-5-to-5-Ton-AC-Heat-Pump-CSR-U-2-/271667274051

[Mary B]

The AC unit is an old 240 volt window unit that is almost dead. She was complaining today it wasn't blowing cold so I think the leak finally emptied the compressor of freon. She needs to get a new efficient window unit and save $50 month on cooling! Power company also knows that it is an issue and that the transformer is dying. Problem is they do not fix anything until it is totally dead!