Me and a few teammates need to build a wind turbine for a certain course this semester and i have quite a lot of questions, so i'm hoping somebody here can help me or point me in the right direction. We are already given some components:

• brushless motor: Turnigy Aerodrive SK3 - 6374-149kv (https://hobbyking.com/en_us/turnigy...rushless-outrunner-motor.html/?___store=en_us)
• ARM: Cypress CY8CKIT-049-41xx PSOC 4
• AC to DC converter: STMicroelectronics VIPER53SP-E (http://www.st.com/content/ccc/resou...df/jcr:content/translations/en.CD00144872.pdf)

The ARM is to measure all kinds of information and display it on an LCD, which will be taken care of by some of my teammates. I need to design a circuit which converts the three fase AC from the generator to DC to charge a lead acid battery. (eventually i need to print a pcb)
I was planning on using a buck converter and a boost converter to convert the DC voltage from the AC-DC converter to the needed DC voltage to charge the battery.

To charge a lead acid battery, do i just need to apply around 14V DC to the battery?
Since the generator output will vary depending on wind speed how do i send the current through the right circuit (buck or boost converter)?
For the switches in the buck/boost converter i would probably use mosfets, but how to i control these so that the converter outputs the needed voltage to charge the battery?
For the AC-DC converter, i was thinking to directly connect the battery to Vdd, using source and drain for AC-DC conversion, adding a 10nF capacitance to the COMP pin (recommended in datasheet p30) and not connecting the others pins. Would this create any problems?

Thanks in advance for any help.

 

Have a look at this, concerning battery charging.

how do i send the current through the right circuit (buck or boost converter)?

You can use a buck-boost converter.

 

Have a look at this, concerning battery charging.

You can use a buck-boost converter.

To select components for a buck-boost converter, with what power rating should i go?
The 70A at 44V maximum input for the motor seems a bit high to me.

 

To select components for a buck-boost converter, with what power rating should i go?

Depends on the maximum power output of the turbine. Have you done the maths for output as a function of maximum wind speed and rotor size?

 

Depends on the maximum power output of the turbine. Have you done the maths for output as a function of maximum wind speed and rotor size?

No we haven't, but we are building a vertical type wind mill so we dont need to turn our turbine when the wind shifts.
Our professor said we could use the maximum input for the motor (70A @ 44V).
Some things have changed in the meantime, instead of using the AC to DC converters for AC to DC conversion, we will be using them as the switches for the buck-boostconverter and we will be using 6 diodes to make a bridge rectifier for 3 phase AC.

turbine -> bridge rectifier -> buck-boostconverter -> lead battery

We are planning on using the ARM to measure the output voltage of the buck-boostconverter en let the ARM control the octocouplers that control the switches (AC-DC converters) so that the output voltage remains constant.

 

so that the output voltage remains constant.

Read up about charging led acid batteries. The voltage won't be constant for all parts of the charging profile. You will also need to consider where you will dump surplus energy once the battery is charged.