Using Victron MPPT for wind turbine

Question

question

brokenlegg asked Jul 4, '19

Using Victron MPPT for wind turbine

My 24v 1040ah system is running with 2.6kw of solar controlled by two MPPTs in parallel, a 3kw multiplus, a Venus GX, and a BMV-712.

I am wanting to add a wind turbine to the system, and as I have a spare blue solar MPPT I was wondering if anyone has any experience with this? If I get a 48vdc turbine I think the MPPT would do the job. I was thinking if I use one of the relays in either the Venus or the BMV to switch a larger power relay to divert the turbine output from the solar controller to some dump load resistors when SOC reaches 100%, this would stop the turbine from free spinning? And also if I put the resistors in the right location I can use them for heating if required.

This would a be preferable setup for two reasons, one because I already have a spare co troller, and two because it would make tracking power generation a lot easier as I could use the Venus for it.

Would love to know everyone’s thoughts.

MPPT Controllers SOC Hydro and Wind Power

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Modifications Space

Node Red Space

Answer 1 · 2019-07-04T10:39:34Z

wkirby answered · Jul 04, 2019 at 10:39 AM

Connecting a wind turbine directly to a solar MPPT is not advisable. The reason is that unlike PV, a wind turbine can output much higher open circuit Voltages when it is not loaded up.
When the battery is full or the MPPT controller goes high impedance at the beginning of a MPP scan the wind turbine output could exceed that of the MPPT's maximum input (PV) Voltage causing it to be damaged. Also the Voltage range of the scan is a bit too wide for turbines and they can stall, take a while to spin up again resulting in repetitive false scans.

Basically there needs to be a device to limit or clip the turbine Voltage to safe limits and also the MPPT algorithm needs to be tailored to wind turbines.

1

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

brokenlegg commented · Jul 04, 2019 at 11:04 PM

What if I use the 48v output of the turbine controller, this will mean I’ll get the MPPT charge profile, rather than just a straight DC voltage?

0 ·

Answer 2 · 2019-07-05T11:19:22Z

sean answered · Jul 05, 2019 at 11:19 AM

A PV MPPT charge controller is not suitable for use with a WT, doing so will give very unpredictable performance (understatement)

Suitable charge controllers, such as some Outbacks, have a mode that allows users to manually enter an fixed I/V curve, this data is usually provided by the manufacturer, or can be found by experiment and observation.

This image illustrates a typical manually entered curve for a ABB inverter.

kw3-std-curve-2.png (228.6 KiB)

2 |3000

Attachments: Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

question