Wind Generator Charge Controller

[dlauginiger]

After extensive research on charge controllers I have found that they operate differently for wind generators than they do for solar arrays.

For solar arrays:
When a charge controller is used with a solar array, it is in the charge path and will"disconnect" the solar array from the batteries when the batteries are full. Apparently this stops current flow without damage to the array.

For wind generator:
Wind generators must always have a load (batteries or dummy) to push their power to so diversion control is needed. It is my understanding is that when used in diversion control mode, the charge controller is NOT in the charge path but monitors the batteries in a shunt fashion. When the batteries are full, the controller siphons power off the batteries to prevent overcharging.

What I am looking for is a charge controller that will actually brake the wind generator when the batteries are full. I have heard of these but have not found one yet.

I recently purchased a Xantrex C60 for my KISS wind generator but don't savor the idea of running additional wires to a dummy load or to the water heater. I am not comfortable with a big resistor heating up on my boat nor do I like the idea of running additional wires back to the heater option.

Any feedback you can give on other make/models would be greatly appreciated.

David

[john61ct]

Originally Posted by dlauginiger

For solar arrays:
When a charge controller is used with a solar array, it is in the charge path and will"disconnect" the solar array from the batteries when the batteries are full.

Actually I haven't come across this feature, links would be appreciated. Most go to float level voltage.

[Mike OReilly]

The wind gen controller that came with my Silentwind works as you describe. Simple voltage and/or amp cuttoff that puts the gen into brake mode. Direct monitor of battery. No shunt.

[dlauginiger]

Originally Posted by Mike OReilly

The wind gen controller that came with my Silentwind works as you describe. Simple voltage and/or amp cuttoff that puts the gen into brake mode. Direct monitor of battery. No shunt.

Is the controller a Silentwind or just the generator?

[hellosailor]

dl-
Even the engineers argue over what "generator" means versus "alternator". But traditionally in the US, a generator has one set of magnets and one wire coil, so it can be started up without any external power. And the faster it turns, the more voltage it puts out, period.
An alternator uses two coils, and requires external power to start, but that also means you can control the output by controlling the exciter voltage that is put into it, regardless of speed. This allows for better voltage control and a wider operating (rpm) range, although generators usually outperform alternators at low rpm, making them more suitable for low wind (typical) output.

There are some wind "generators" that are actually better called "turbines" or wind alternators, and those can be controlled like traditional alternators, no dump load needed. And others that have mechanical brake assemblies, so they can be locked down instead of damaged by high speed winds.

If you beat the bushes, you'll find some that meet your needs.

[Mike OReilly]

Originally Posted by dlauginiger

Is the controller a Silentwind or just the generator?

The controller is sold by Silentwind, but appears to be one built by a third party. I've seen them for sale under different brands.

I don't know how the braking mechanism operates on my SW. Seems like a mechanical brake being applied once battery voltage is achieved.

SW has full specs for the controller on their website.

[GILow]

Originally Posted by dlauginiger

After extensive research on charge controllers I have found that they operate differently for wind generators than they do for solar arrays.

For solar arrays:
When a charge controller is used with a solar array, it is in the charge path and will"disconnect" the solar array from the batteries when the batteries are full. Apparently this stops current flow without damage to the array.

For wind generator:
Wind generators must always have a load (batteries or dummy) to push their power to so diversion control is needed. It is my understanding is that when used in diversion control mode, the charge controller is NOT in the charge path but monitors the batteries in a shunt fashion. When the batteries are full, the controller siphons power off the batteries to prevent overcharging.

What I am looking for is a charge controller that will actually brake the wind generator when the batteries are full. I have heard of these but have not found one yet.

I recently purchased a Xantrex C60 for my KISS wind generator but don't savor the idea of running additional wires to a dummy load or to the water heater. I am not comfortable with a big resistor heating up on my boat nor do I like the idea of running additional wires back to the heater option.

Any feedback you can give on other make/models would be greatly appreciated.

David

Been here, got the scars... mainly small burns from the soldering.

Yep, controllers like the Morningstar Tristar (https://www.morningstarcorp.com/products/tristar/) support dump loads, but from the wiring diagrams they appear to do it by dumping load directly from the battery. NOT good trying to get that working with, say, a good quality solar regulator that is trying to run an intelligent charging profile.

Meanwhile, older style controllers like the now obsolete unit that came with my Aerogen (https://www.jabscoshop.com/site-map/...ro6gen-12v.htm) divert power BEFORE the battery to the dump load, which is better when trying to get a smart charge profile solar regulator working, provided you can adjust the switching voltage and set it at or BELOW the float voltage.

But in each case, they dump power to a dump load, and GENERALLY, the simplest dump load is going to be a heater element because that's the quickest and easiest way to get rid of electrical energy. Actually, I am hard pressed to think of any other way... maybe some fans that move air... or liquid... a motor that stirs a tank of liquid perhaps... the thing is, you have to get rid of energy to electrically brake a wind gen, unless the gen itself has some kind of built in electrical feathering brake, or brake band...? Never seen one that did either of these things that was not a 2 Megawatt unit on a 100 meter high pylon. (Wind Turbine : Hitachi)

Edit: Looking at Mike's silent wind it seems like the dumping of power happens in the windgen itself, which is smart. They describe this as electronic braking. Interesting.

But honestly, i think you are worrying too much. Our 300+ watt Aerogen 6 uses dump resistors. Sure, they get warm, very rarely a bit too warm to touch comfortably, but getting rid of 300 watts of heat is not hard to do safely. I don't know about your layout, but in my case I have a big aluminium panel (about 300 mm square) with the dump resistors bolted to the panel, and the panel itself mounted with stand-offs to the back of a small locker bulkhead right near the electrical system with my own home-made regulator a few inches away. Works a treat, and the aluminium panel has never even become slightly warm. No fans needed, just a natural convection path designed into the locker, with a pair of ventilation grills top and bottom. No moving parts, no crappy computer fans to seize up, no maintenance at all, except, I guess, making sure the grills don't clog with fluff or something, but there's been no evidence of that so far. A small cage over the whole lot if it's the kind of locker that might have something put in there by mistake. (not the case with my little locker)

If you are worried about heat in the boat... well don't. At MOST you are going to be talking maybe 360 watts for a good wind gen at FULL output. (Very, very rare indeed) On a winter's day, that's not going to make a dent, and on a summer's day you'll be getting so much heat through the deck that 360 watts will be a drop in the ocean.

If you are REALLY worried about some kind of a fire or something, put the element in a small water tank (one or two liters, filled with coolant), and put cooling fins on the outside of the tank. Easy.

[GILow]

Originally Posted by Mike OReilly

The controller is sold by Silentwind, but appears to be one built by a third party. I've seen them for sale under different brands.

I don't know how the braking mechanism operates on my SW. Seems like a mechanical brake being applied once battery voltage is achieved.

SW has full specs for the controller on their website.

I seriously doubt it is a mechanical brake. The maintenance of such a device would be a nightmare, the spare parts list for the generator would have to include brake shoes.

A simple short circuit on a wind gen has an astounding braking effect, more than you'd possibly think.

[Jim Cate]

Our Air-X uses a simple shorting switch to brake the turbine. Works a treat, so I have never understood the principle of using an expensive resistive load when a bit of copper wire will do just fine.

BTW, this ain't a yottie McGyver setup,it is what the OEM says to do... the shorting switch came from them!

Jim

[GILow]

Originally Posted by Jim Cate

Our Air-X uses a simple shorting switch to brake the turbine. Works a treat, so I have never understood the principle of using an expensive resistive load when a bit of copper wire will do just fine.

BTW, this ain't a yottie McGyver setup,it is what the OEM says to do... the shorting switch came from them!

Jim

I tried the direct shorting method on our Aerogen 6 and I melted the brush pack on the mounting pivot, then the resulting overvoltage in the generator blew the bridgegate rectifier into it's component elements. I am glad this has not happened to your Air-X (and probably wont), but I think it is worth noting the risk, particularly if someone is using a windgen with a brush pack at the pivot point. A little bit of electrical resistance in those brushes can generate a lot of heat in a big wind. If they then fail, and if your bridgegate is upstream of the brushes, then you can pretty well guarantee an over-voltage event at the bridgegate. Ours was rated to 500 Volts and still blew spectacularly.

Of course the dump load is pretty much the same thing as a short circuit, albeit with a higher voltage and a lower current, and the lower current means less problems at points of electrical resistance such as brush packs.

FWIW, it looks like the Silentwind switches to electrical short mode inside the generator itself. I think this could be done quite neatly with a set of MOSFETs inside the case, I wonder if that is what they have done? I am going to look into this for our setup, it might solve my current dilemma which is that I have to tie off the Aerogen whenever I am away from the boat. (Incidentally, this is as per the Aerogen instruction manual and is only applicable to the Aerogen 6, not the smaller models.)

Anyway, just a word of caution to anyone thinking of the direct short method on other generators where it is not explicitly recommended, it is good, but it MAY have implications.

Matt

[hellosailor]

Matt-
I see the Air-X products referred to as wind "turbines" with microprocessor controlled "alternators", but never a mention of "generator". It may be that simple. You can brake them without slagging them down, because they are not generators.

"Ignore the man behind the curtain" still works. A true generator, still will need a dump load. A friend of mine has a motorcycle with a generator (bikes always used to use generators, not alternators) and every time the wiring to the dump resistors get flaky? Right, he burns out another generator.

[Jim Cate]

Matt, perhaps the difference is the blade configuration. IIRC, the Aerogens use a multi-blade array with a lot of blade area. Low efficiency, but high torque at stall speeds. The air-x uses long skinny blades, relatively low blade area, low torque at stall, high efficiency when spun up.

Thus, when shorted, the Air-x just stops, or turns at a few rpm, because it can't generate enough torque to overcome the very high drag of the shorted alternator*, and thus generates near to zero power... so no heating of anything.

The Aerogen when shorted continues to spin fast enough to produce some power and hence some heating... a insidious result of that high torque at stall.

*And yes, the Air-X is an alternator, but uses permanent magnets rather than field coils to produce the required mag field. The regulation is done with PWM, not by reducing the field current as in an automotive alternator. I dunno why one would not call it a "generator", 'cause it does generate electricity. The devices HelloSailor refers to are DC generators... a different breed of cat, and not relevant to our discussion.

So, continue to tie off your silent but deadly Aerogen and leave the shorting to others!

Jim

[HankOnthewater]

I agree with Gilow's posts. I have an Aerogen 4, D400, Air Marine and KISS.
The manuals of the first two do not recommend shortcuiting the outputs permanently, just temporarily, to slow the blades down and then mechanically secured them.
BTW, the Aerogen 4 comes with one large resistor and the D400 comes with two of these, identical ones.
The controllers for these (both LVM) can be adjusted for dumping Voltage.
The air marine and KISS (I have) both are provided with electric/electronic brakes (NOT mechanical). When one activates this brake.... not sure how hot the actual unit gets, the switch is certainly not hot.

To me the ideal setup is to divert the excess output to a heater element in the hot water tank. But I have not seen tanks that can accommodate a 2nd or 3rd element (in addition to the mains 110 or 240 Volt one).

[john61ct]

Load shedding besides heating water:

Eutectic holding plates in the reefer, even a dedicated icemaker.

Or watermaking.

Or topping up a secondary LFP bank.

[GILow]

Originally Posted by HankOnthewater

The controllers for these (both LVM) can be adjusted for dumping Voltage.

Unless, like me, you have one of the VERY few LVM regulators where the trimpot is not accessible. Yeah, I got lumbered with the only non-adjustable version they ever made. :^( Most of the distributors I corresponded with didn't even know they existed. I had to send photos to prove I there was no hole for the adjustment pot.

Just one of the reasons I ended up making my own.