Solar inverter & Voltsys with wind turbine

[Paul Pavone]

Gents; our ducted wind turbine is performing very well (ductedwind.com). Our issue is the downstream electrical. We have tried several inverters. We are using a ABB wind interface box with a ABB solar inverter and Voltsys MPPT. See the voltsys site and you can see the system. It works fine until the voltage reaches 500+ and the recifier kicks the dump load on. Then the inverter indicates an arc fault and shuts down. I have seen Robs diagram of the over voltage schematic. My question is the speed of the over voltage components to allow the dump to kick in and not effect the inverter. I am still puzzled why the inverter shows an arc fault when the dump load is on with the ABB rectifier. We have found a new inverter company in Texas and are asking them to add wind MPPT software to their solar inverter. Thanks for any suggestions, comments, or thoughts.

Paul

[Rob Beckers]

Paul, the inverters detect arc-faults by 'listening' for noise on the DC input. So, any switching (contactors) or even the rectifier (inherently noisy because they only conduct during a very small part of the input AC) could potentially set it off. On top of that, AFCI detection in inverters really is not very good. There are lots of cases of solar inverters that throw bogus arc-faults. I'm guessing it's tough to detect reliably, and a tradeoff between sensitivity and false-positives.

Can't you get access to the internal settings to disable the arc-fault mechanism? For ABB inverters that should be someplace in the factory settings that require the individual access code based on serial number (send me an E-mail and I'll tell you how to calculate those, should still work unless ABB changed their algorithm). Or even just defeat it mechanically: Most inverters I've seen use CT-coils to detect the noise on the DC lines. Moving those coils/wires so they're no longer enclosing any DC wires would defeat AFCI without having to making any setting changes in the inverter.

Obviously AFCI doesn't make sense when your wiring is 3-phase AC...

-RoB-

[Paul Pavone]

Thanks Rob; We believe the arc fault is be caused when the ABB rectifier WIB kicks on the dump load. We will check the arc fault component as ABB indicated that they have upgraded this component. I will let you know how it all works out. You need to come visit at Clarkson University and see the turbine. We are also trying a new inverter called Sol-Ark. We really like this one and they are installing a wind MPPT software for us. I'll keep you updated.

Thanks for all your help.

Paul

[Dwain Seltzer]

In what way did ABB upgrade that component? What did they change about it?

[Paul Pavone]

ABB didn't change their wind inverters for small wind. We are using a solar inverter with a wind controller for inputing the power curves that we need to maintain a load on the turbine at variable wind speeds. We are under contract with a solar inverter company for software to be installed a designing an inverter specifically for our wind turbine. www.ductedwind.com. We will be taking delivery of the first one in two weeks for real time testing. We should be able to run two turbines from one inverter. The inverter will have built in rectifier, energy storage capability, and micro switching to a diesel genset. Also, off grid or on grid.

We will post our results when available.

Paul

[Harry Pham]

ABB didn't change their wind inverters for small wind. We are using a solar inverter with a wind controller for inputing the power curves that we need to maintain a load on the turbine at variable wind speeds. We are under contract with a solar inverter company for software to be installed a designing an inverter specifically for our wind turbine. www.ductedwind.com. We will be taking delivery of the first one in two weeks for real time testing. We should be able to run two turbines from one inverter. The inverter will have built in rectifier, energy storage capability, and micro switching to a diesel genset. Also, off grid or on grid.

We will post our results when available.

Paul

Thanks for share this