Three Phase Basics

Three phase electricity

An excellent resource for anyone interested in understanding why the majority of wind turbine generators are wired in three phases should take a look at this excellent article on Three Phase Basics from Find out about the differences between wiring in Delta or Star configuration, and calculate how many RPM your turbine will need to spin at in order to start charging your battery bank.

Another useful polyphase electricity article can be found at the Standford website: The polyphase motor/generator.

Click here for our article on a putting together a Three Phase Voltage Multiplier, and here for details on Making a Three Phase Bridge Rectifier.


Both of the sites that your section on “Three Phase Basics” links to are wrong in their wiring details and not even in the same way.

Let’s start with the “polyphase motor/generator”: this one really threw me because he has pictures of one he made, and goes into great lengths on the theory, with complicated diagrams and even more complicated fumulae. I thought “how can this guy be wrong, he really knows what he’s talking about and anyway, he built it, didn’t he; so it must work”. Yet, at the same time, the wiring was bound to cancel out the current and leave him with nothing.
Eventually, after much head scratching, I happened to check other articles by the same person on that site, and found that, in the one about a “single phase motor/generator”, he admits that his three phase generator didn’t work. Surprise, surprise!
So did he leave it on the site just to confuse people like me?

The other one is wrong in a different way but seems to share the same error of not understanding the fundamental difference between single-phase and multi-phase.

I think it’s very important that this wrong information is corrected as, otherwise, people will spend time and money making things that don’t work.

April 25th 2008