Advice on a good wind controller

vomus · September 2014

Hi!
I just installed wind maglev turbine for my 48V system and it seems to work well enough. However, it came with a rather bad controller that I would like to replace with something more sophisticated (a Xantrex alike device). Can anyone give any advice on what might be a good replacement?

1) I would like the controller to turn on for as low wind as possible. The one I have seems to wait for quite a while before starting to spit amps into my batteries. It would be nice to collect as many amps as possible. May be there is a controller that can be adjusted.

2) It would be very good to be able to adjust a floating voltage so I could accommodate different types of batteries. The controller I have now has 58V hardwired into its brains but my batteries would prefer 54.4V when they are in a buffer mode. In general, adjusting bulk/absorption/float voltages would be a real plus.

3) It would be really cool if the controller had some remote management option like RS232 or IP and I would be more than happy if it was exposing its parameters through Modbus so I could integrate it into my "smart home" system. :-)

Thanks a lot in advance,

Photowhit · September 2014

Re: Advice on a good wind controller

I'm not a wind guy... but sounds like a Midnite classic. The Xantrex C40 might work as well, I think some of the voltage levels are adjustable, and it's a PWM controller.

The not delivering and current might have to do with it not spinning up, voltage increases as it spins up and it has to turn at a certain rate before it achieve minimum voltage.

BB. · October 2014

Re: Advice on a good wind controller

There are (at least) two different ways of connecting your controller to your battery bank.

The typical method is to have the Wind Turbine:

Wind Turbine => DC rectifier => Battery Bank => Dump Controller => load bank (resistance heaters typically)

In this case, the turbine is always connected to the battery bank and dumping all available energy (Alternator output>Vbatt) to the battery bank. Then a "dump/shunt/diversion/bypass" type charge controller monitors the battery bank voltage--When battery is "full", the controller turns on and dumps current to the resistor bank (waste heat).

Another type is to use a MPPT type charge controller (some with integrated resistor load bank). The MPPT charge controller lets the turbine operate at optimum RPM/Voltage/Current and take the high voltage/low current from the turbine and efficiently down convert it to low voltage/high current needed to charge the battery bank.

Wind Turbine => Rectifier/Load Bank controller => MPPT charge controller => Battery Bank

In theory, it has been reported that some test systems produced 2-3x the energy with an MPPT controller vs the standard PWM Dump controller in example one.

A couple of controllers you can read the instructions on:

Schneider Electric C40 40 Amp Solar Charge Controller (simple PWM diversion controller)
http://www.solar-electric.com/inverters-controllers-accessories/chco/misoclchco.html (Midnite MPPT classic + clipper controllers)

I don't know much about the details of the Midnite system... If your turbine gets good wind and generates significant power normally, then a MPPT type charge controller can help you harvest more.

If you do not get good wind, or get significant power from the wind turbine due to design issues/trees/buildings blocking prevailing wind, then a MPPT charge controller will probably not help you. The turbine has to be generating good voltage/current and you want better. If the turbine barely produces enough voltage to charge the battery bank--The MPPT controller will not help at all as the turbine does not produce a minimum amount of power in the first place.

-Bill

vomus · October 2014

Re: Advice on a good wind controller

BB. wrote: »

There are (at least) two different ways of connecting your controller to your battery bank.

The typical method is to have the Wind Turbine:

Wind Turbine => DC rectifier => Battery Bank => Dump Controller => load bank (resistance heaters typically)

In this case, the turbine is always connected to the battery bank and dumping all available energy (Alternator output>Vbatt) to the battery bank. Then a "dump/shunt/diversion/bypass" type charge controller monitors the battery bank voltage--When battery is "full", the controller turns on and dumps current to the resistor bank (waste heat).

In this case what would I do if a voltage from my turbine becomes higher than what a particular battery is optimized for? How do I regulate rectifier's output? In other words this element has to be not just a simple bunch of diods. I have never worked with a three-phase rectifiers which have to be used here and which are somewhat more complex.

Another type is to use a MPPT type charge controller (some with integrated resistor load bank). The MPPT charge controller lets the turbine operate at optimum RPM/Voltage/Current and take the high voltage/low current from the turbine and efficiently down convert it to low voltage/high current needed to charge the battery bank.

Wind Turbine => Rectifier/Load Bank controller => MPPT charge controller => Battery Bank

In theory, it has been reported that some test systems produced 2-3x the energy with an MPPT controller vs the standard PWM Dump controller in example one.

The scheme with an MPPT sounds a bit more attractive (mostly because I have a spare Xantrex MPPT60-150 :-)). What will a Load Bank controller do in this case and what can be used for such a purpose? When you say a "Load bank" you mean "Dump load"?

A couple of controllers you can read the instructions on:

Schneider Electric C40 40 Amp Solar Charge Controller (simple PWM diversion controller)
http://www.solar-electric.com/inverters-controllers-accessories/chco/misoclchco.html (Midnite MPPT classic + clipper controllers)

I don't know much about the details of the Midnite system... If your turbine gets good wind and generates significant power normally, then a MPPT type charge controller can help you harvest more.

If you do not get good wind, or get significant power from the wind turbine due to design issues/trees/buildings blocking prevailing wind, then a MPPT charge controller will probably not help you. The turbine has to be generating good voltage/current and you want better. If the turbine barely produces enough voltage to charge the battery bank--The MPPT controller will not help at all as the turbine does not produce a minimum amount of power in the first place.

-Bill

My turbine reaches 46V at rather large winds, about 9 m/s.

BB. · October 2014

Re: Advice on a good wind controller

vomus wrote: »

In this case what would I do if a voltage from my turbine becomes higher than what a particular battery is optimized for? How do I regulate rectifier's output? In other words this element has to be not just a simple bunch of diodes. I have never worked with a three-phase rectifiers which have to be used here and which are somewhat more complex.

Actually, the whole turbine/alternator/rectifier is actually quite straight forward... Very similar to the components on an automotive Alternator (without the regulator circuit).

http://www.thebackshed.com/windmill/articles/Rectifiers.asp

The scheme with an MPPT sounds a bit more attractive (mostly because I have a spare Xantrex MPPT60-150 :-)). What will a Load Bank controller do in this case and what can be used for such a purpose? When you say a "Load bank" you mean "Dump load"?

Wind turbines tend to operate with rapidly changing RPM and wind conditions... I do not know if a Xantrex MPPT controller would track a wind turbine well or not (I would tend to think not)... Perhaps somebody here can help answer that question.

Yes, load bank or dump bank--Same thing.

My turbine reaches 46V at rather large winds, about 9 m/s.

You have to know more about the turbine than 46 volts... A 48 volt flooded cell battery bank needs about 59 volts or more to fully/quickly charge.

A turbine may output 46 VDC from the rectifier--Which is too low to recharge a 48 volt battery bank... Or it may be getting 46 VAC which will work out to around 60-65 VDC (after the full wave rectifier), which is enough voltage to recharge a 48 VDC battery bank.

Also, the operating voltage is heavely dependent on the state of charge of the battery bank... When the battery ban is well discharged (below 50% state of charge), it may be ~48 VDC when "resting" (several hours of no charging/discharging current). You need to raise the battery bank voltage to a minimum of ~56 VDC to get some decent charging current into the battery bank. A 1,000 Watt @ 48 volt turbine should be able to output ~20 amps in rated wind speed--But man times is much less because of low average wind speeds at the turbine.

Do you have a link to the turbine website/manual/specifications? This sounds like it may be a vertical axis wind turbine. They tend to be mounted too low (less than 10 meter tower) and don't really work well in less than very windy conditions.

-Bill

vomus · October 2014

Re: Advice on a good wind controller

BB. wrote: »

Wind turbines tend to operate with rapidly changing RPM and wind conditions... I do not know if a Xantrex MPPT controller would track a wind turbine well or not (I would tend to think not)... Perhaps somebody here can help answer that question.

I guess this will probably be understood from an experiment only. What would I tune the Load Controller to in such a scheme? Would I set a threshold to something like a 0.1V higher than a float voltage of my batteries? MPPT will (or will try) to maintain float voltage. What would I do when a bulk/absorption stages occur?

You have to know more about the turbine than 46 volts... A 48 volt flooded cell battery bank needs about 59 volts or more to fully/quickly charge.

A turbine may output 46 VDC from the rectifier--Which is too low to recharge a 48 volt battery bank... Or it may be getting 46 VAC which will work out to around 60-65 VDC (after the full wave rectifier), which is enough voltage to recharge a 48 VDC battery bank.

Also, the operating voltage is heavely dependent on the state of charge of the battery bank... When the battery ban is well discharged (below 50% state of charge), it may be ~48 VDC when "resting" (several hours of no charging/discharging current). You need to raise the battery bank voltage to a minimum of ~56 VDC to get some decent charging current into the battery bank. A 1,000 Watt @ 48 volt turbine should be able to output ~20 amps in rated wind speed--But man times is much less because of low average wind speeds at the turbine.

Do you have a link to the turbine website/manual/specifications? This sounds like it may be a vertical axis wind turbine. They tend to be mounted too low (less than 10 meter tower) and don't really work well in less than very windy conditions.

46 volts per phase is the voltage that my current controller waits for to start dumping current to batteries. It is kind of dumb I believe, it waits too much and then starts regulating in a step-down fashion. In might have been smarter closing the circuit earlier and doing a step-up.

Speaking of the turbine... Yes, it is a vertical 1 kW Maglev. The picture (of a 300W) is here, for example http://www.diytrade.com/china/pd/12283894/300_3KW_Maglev_Wind_Turbine_Wind_Generator.html. It is mounted on a 10 meter tower.

Advice on a good wind controller

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