Inverters
Data used by the engine
| Data | Use |
|---|---|
| Nominal and maximum AC power | Power limit and clipping |
| Maximum and European efficiency | Simplified efficiency model |
| Number of MPPTs | Independent inverter inputs |
| MPPT voltage range (min. and max.) | Electrical validation |
| Maximum DC voltage | Electrical validation (cold Voc) |
| Maximum current per MPPT | Parallel strings per input |
| Phase | Single-phase or three-phase (AC cabling) |
| Battery compatibility | Which batteries are offered |
| Efficiency curve (if there is an .OND) | Real efficiency according to power and voltage |
| Night-time consumption | Own stand-by consumption |
Efficiency model
There are two models and the engine uses the best one available:
- Measured curve (PVsyst .OND file): efficiency profiles by DC voltage. The efficiency depends on the power and on the voltage at which it operates each hour. It includes the start-up threshold and the night-time consumption.
- PVWatts (NREL): simplified model based on the nominal power and the European efficiency, with a reference efficiency of 96.37 %.
Details in Inverter and clipping.
Night-time own consumption
The inverter consumes a little in stand-by at night. Radiaris treats it as one more load: it takes it from the grid or the battery, and records it separately so as not to alter the user's consumption.
Several inverters
You can use more than one inverter in the same project. Each one works in one of these modes:
| Mode | Meaning |
|---|---|
| Shared MPPT | The inputs share the power as a single set |
| Independent MPPT | Each MPPT input works on its own with its own voltage |
In the topology you assign each MPPT input to an inverter.
DC/AC ratio
The peak power of the modules (DC) divided by the nominal power of the inverter (AC). A ratio >1 is normal and desirable (the inverter works more hours near its nominal power), but too much causes clipping. The engine limits the ratio to a configurable maximum (1.4 by default). See Electrical validation.