Key Concepts developing a test bench bed for an inverter connected to the public grid

Hey there!

I need to write a short document about how I should approach the develop of a test bench for the control of various inverters conected to the public grid.
I attached a picture of something looking like I mean. It should be like HEMS in the picture.


Firstly I thought in these points:

Hardware:

• Check the correct sensing of the voltage and current of the different inverters and plugs.
• Check the isolation of the sensing lines.
• Check its immunity to EMC, both conducted and radiated.

The control

• Add test routines to check the correct operation of the FPGA/DSP.

Interface

• Try the proper working of the differents modes of configuration.
• Debug the interface.

I am a bit lost about this kind of things and I need to know if there are something more interesting to check or if I've wrote it is a nonsense.
Also any technical key concept would be welcome.

Regards

What happens when the grid gets struck by lightning? In general I thought that wind turbines and solar cells charged up a battery, which is then inverted and fed into the grid. This means that there is one LV-mains inverter and not three as in your diagram, also it has an easier life as its input volts will change by 15% at the most and its just one synchronising circuit.
Frank

So I have to add "Check the HEMS front overcurrent and overvoltage" in Hardware testing.
What do you mean with just one synchronising circuit?

Thanks
Regards

You missed out the most important concept - "anti islanding", the ability to disconnect all power sources if the incoming grid connection fails. It is a legal requirement that all sources of power are immediately isolated from the grid to preven it being 'back driven' from the inverters. In view of it being a wireless controller, you would also have to ensure the latency in communications didn't slow it's reaction time too much.

Brian.

In what world does every outlet have a wifi connection? Seriously now, even new tech like solar inverters won't have that (or even a wired network).

chuckey said:

In general I thought that wind turbines and solar cells charged up a battery, which is then inverted and fed into the grid.

Click to expand...

This is sometimes the case, though it's something we're trying to abandon in favor of microinverters.

So finally it should be something like this:

Hardware

• Check the correct sensing of the voltage and current of the different inverters and plugs
• Check the isolation of the sensing lines.
• Check the protection against overcurrent and overvoltage
• Check its immunity to EMC, both conducted and radiated.

The control

• Add test routines to check the correct operation of the FPGA/DSP.

Interface

• Try the proper working of the differents modes of configuration.
• Debug the interface.
• Check the latency in communications.

Thank you!