Bipolar Inverters

[SunCharlotte]

Has anyone installed a large PV system (>500 kW) with bipolar inverters? Have a upcoming rooftop project, it is 1 MW and we are using bipolar inverts for the first time. Any feedback/recommendations would be very helpful!

 

[gadfly56]

Has anyone installed a large PV system (>500 kW) with bipolar inverters? Have a upcoming rooftop project, it is 1 MW and we are using bipolar inverts for the first time. Any feedback/recommendations would be very helpful!

Get the lithium dose level just right and they should be fine .

 

[George Stolz]

Get the lithium dose level just right and they should be fine .

:lol:

Okay, now that you stole my line, the next post will be serious (helpful) to the original poster.

 

[ron]

I've used Advanced Energy's 500kVA inverter which is bipolar. It involves running essentially the same number of panels, but the fact that additional common conductors are run, requires specialty combiner and fused switches.

 

[ron]

There is a simple diamgram of a bipolar array @ http://www.idealpowerconverters.com/photovoltaic-inverter.aspx

 

[ggunn]

Has anyone installed a large PV system (>500 kW) with bipolar inverters? Have a upcoming rooftop project, it is 1 MW and we are using bipolar inverts for the first time. Any feedback/recommendations would be very helpful!

I have done several sales designs with these, although as yet none have been installed. What inverters are you using? What questions do you have? The manuals for these inverters are usually pretty succinct.

Most require that the upper (positive) and lower (negative) subarrays be balanced, i.e., they must have the same number of modules in the same string length and string count. You will want to run the conductors for the upper and lower subarrays in separate conduits because there is twice Voc potential between the upper positive and lower negative conductors. Some (most?) are ungrounded on the DC side, which means that none of the conductors are connected to ground in the inverter, although all the normal Equipment Grounding Conductor rules are unchanged. Some offer the option of a remote center point so that you do not have to run the negative conductor from the upper array and the positive conductor from the negative array all the way back to the inverter.

What else can I tell you?