MPPT for VAWT, concept drawing
Hi, I have a working system. I fabricated the PMA and VAWT. I have it configured using a bridge rectifier to the battery bank and a dump load controller monitors the batteries to protect from over charging.
Because I fabricated the PMA with inputs and outputs on each stator I am able to connect the coils to form
a 3 phase Star with 12 coils per phase. When the PMA, permanent magnet alternator, is connected to a 12 volt deep cell battery using a bridge rectifier, the voltage is locked at the voltage level of the battery and as the turbine RPM increases the bridge rectifier output current increases and over time the battery voltage increase until the dump load control diverts the current. So it acts a current source.
When the PMA is not connected to a battery bank and has no load it spins freely and the measured voltage can be very high depending on the RPM. With no load I can spin it manually and measure 60 Vdc.
Because the PMA will act differently with different loads I am having difficulty developing a algorithm for MPPT controller and determining values needed to design MPPT circuit.
I do know the PMA is capable of 30 amps max output.
MPPT circuit parameters:
V in = 15 to 60 Vdc
I out max = 15 amps
V out = 13.5 Vdc
Because I am charging 12 volt deep cell batteries I do not know if regulation of the output is important.
I am planning on fabricating a simple buck circuit with a fixed oscillator and use the PMA at fixed RPM for V in of the MPPT and using a 12 volt deep cell for a load to determine if there is a increase in the amp output can be measured.
This is a first attempt and I still reviewing MPPT strategies.
This is a new project so the values and circuit can change. The objective is to improve turbine performance and increase current output.
Thank you any help received. Comments welcome