want your help!

okey..my group has just been given one task to design a renewable energy system for home usage..so, we want to use plc in order to set whether to use the main source from our current supply power(paid) or use the power generated by the renewable energy(in this case we use wind turbine)..so we need to set the system to supply according to the power usage of electrical devices..if any of you have any idea, can just share with me..thanks a lot

Home work right?

What information have you gathered so far?

Have you determined your power supply capacity? (Wind Turbine Cap.)

Have you determined your loads?

Have you determined how to extract the power usage to PLC?

If have answers to those, it is just a matter of switching the source power using PLC outputs, when the turbine capacity is used up.

thanx chavak..

Switching thats the key word he he.

Computer UPS they switch the power within milliseconds from the battery to the line and vice versa, BuT they are limited to certain power. You have to research something that fast and safe but for biger loads.

Hope that helps

1) determine your requirements (power loads, available power on each system, allowable downtime for switching, etc)

2) pick hardware that will allow you to meet these goals

3) determine a control strategy that will allow you to meet those goals

4) program your hardware with your control strategy

5) test/debug

6) get an A+++ on your homework

No switching required

I suggest you feed your accumulators with one of the sources.

Normally such system is not feed from the grid OR from the renewable source.

The accumulators are what feed your loads.

You design the system to "charge" the accumulators from either sources. The grid would feed only under a certain limit say 25% but that is yours to decide.

This way you never have any disturbance but you also need to supply 100% of your load from the accumulators.

I've seen this type of setup feeding 12 houses in the Caraïbes with HVAC and all.

They also had a backup generator...

You could also feed back the grid when your accumulators are fully charged and you still have some wind to work with.

Pierre's system is the best. If you want to switch one or the other, monitor current. The temptation is to monitor power, but kVA not kW dictates if your source is sufficient. (Why are they different?) Make sure you put some time delays in yor logic so ..... (Why?)

thanx for your reply..i will apreciate it so much..adios