I am currently designing a 20kw photovoltaic system for a large commercial application (480/277WYE) and the customer has requested we engineer the system to hit exactly 20kw. In attempting to do so we have determined one possibility would be the following:
(2) 7000W Inverters (277V output)
(1) 6000W Inverter (277V output)
These three inverters would each utilize a Line to N connection. But I know that the (2) 7kW inverters will be producing at ~25.24A while the (1) 6kW inverter will be at ~21.66A. To my understanding this could be an issue.
Now, please note I am a mechanical engineer by education I have 2.5 years experience with single phase interconnections in the solar industry. But I am still a more or less in-experienced with three-phase.
So I am wondering how I calculate the phase imbalance (if any). The local utility, like most, has a restriction on the imbalance of the power we back-feed. And I can not remember or find instructions on how to calculate this, so if there is a specific formula or process I should go about to determine this I would greatly appreciate any help. OR if there is some other problem regarding this set up please let me know.
Thanks for any/all of your help in advance.
Taylor
Solar Engineering Group
(2) 7000W Inverters (277V output)
(1) 6000W Inverter (277V output)
These three inverters would each utilize a Line to N connection. But I know that the (2) 7kW inverters will be producing at ~25.24A while the (1) 6kW inverter will be at ~21.66A. To my understanding this could be an issue.
Now, please note I am a mechanical engineer by education I have 2.5 years experience with single phase interconnections in the solar industry. But I am still a more or less in-experienced with three-phase.
So I am wondering how I calculate the phase imbalance (if any). The local utility, like most, has a restriction on the imbalance of the power we back-feed. And I can not remember or find instructions on how to calculate this, so if there is a specific formula or process I should go about to determine this I would greatly appreciate any help. OR if there is some other problem regarding this set up please let me know.
Thanks for any/all of your help in advance.
Taylor
Solar Engineering Group