Simulation variables: DC-grid systems
The following variables are calculated during the simulation process, and available as results:
Weather data and irradiation variables: see previous page.
PV array behaviour
| EArrMPP | Array virtual energy at MPP (after wiring, module quality and mismatch losses), Virtual calculation independent of the system state |
| EArUfix | Array virtual energy at fixed voltage Voltage as calculated by the balance loop (real load voltage), or line reference voltage when PV-array disconnected. |
| MPPLoss | Loss with respect to the MPP operation |
| EUnused | Unused energy loss (over the user's demand) |
| Earray | Effective energy at the output of the array |
| IArray | Array Current |
| UArray | Array Voltage |
| ArrayON | State / Duration of the PV production of the array |
System operating conditions
| Esupply | Energy from Conventional Power Supply |
| LigLoss | PV to User Line Ohmic Losses |
Energy use
| E Avail | Produced (available) Solar Energy |
| E Load | Energy need of the user (acc. to Load definition) |
| E User | Energy supplied to the user |
| SolFrac | Solar fraction (EUser / ELoad) |
| U User | User Voltage |
Efficiencies
| EffArrR | Array Efficiency: EArray / rough area |
| EffArrC | Array Efficiency: EArray / cells area (=0 when cells area not defined) |
| EffSysR | System efficiency E User / rough area |
| EffSysC | System efficiency E User / cells area (=0 when cells area not defined) |
Normalised performance index
(Read more about Normalised performance index)
| Yr | Reference Incident Energy in collector plane | = GlobInc [kWh/m²/day] |
| Yu | Normalized Potential PV Production | [kWh/kWp/day] |
| Ya | Normalized Array Production | = EArray [kWh/kWp/day] |
| Yf | Normalized System Production | = EAvail [kWh/kWp/day] |
| Pr | Performance ratio | = Yf / Yr. |
| Lu | Normalized Unused energy | = Yr - Yu |
| Lc | Normalized Array Losses | = Yu - Ya |
| Ls | Normalized System Losses | = Ya - Yf |