The generator is used in the off-grid system to charge the batteries or to cover loads.
The auxiliary generator is started when the state of charge of the batteries (SOC, state of charge) is below the start threshold and continues to operate until the SOC is above the stop threshold again.
$$ SOC \leq SOC_\text{Startschwelle} \Longrightarrow P_\text{Generator} = I_\text{Generator} \cdot U_\text{AC-Netz} $$
$$ SOC > SOC_\text{Stopschwelle} \Longrightarrow P_\text{Generator} = 0 $$
The power is calculated from the generator current. This is either the default generator current or the maximum permissible current of the MultiCluster box, if this is smaller.
If the auxiliary generator is not operated due to the SOC thresholds, the system continues to check for load-related use.:
$$ (P_\text{Verbrauch} - P_\text{PV,AC}) > P_\text{Startschwelle, Last} \Longrightarrow P_\text{Generator} = I_\text{Generator} \cdot U_\text{AC-Netz} $$
$$ (P_\text{Verbrauch} - P_\text{PV,AC}) < P_\text{Stopschwelle, Last} \Longrightarrow P_\text{Generator} = 0 $$
Finally, it is checked whether equalisation or full charging is taking place and the generator must therefore run because the PV power is not sufficient for charging.
The actual fuel consumption of the auxiliary generator depends on its utilization and specific consumption. The specific consumption $C_\text{spline, Verbrauch, Auslastung}$ is defined in the database entry.
Based on the load (current generator power $P_\text{Generator}$ to rated power $P_\text{Generator,Nenn}$) the actual fuel consumption $\dot{V}_{\text{Fuel}}$ is calculated:
$$ \dot{V}_{\text{Brennstoff}} = C_\text{spline, Verbrauch, Auslastung} \cdot \frac{P_\text{Generator}}{P_\text{Generator,Nenn}} $$
See also