What is 1/3-phase switching
Electric cars need a minimum charging current per phase (6 A) to be able to charge.
For 3-phase charging this results in a minimum charging power of 6 A * 230 V * 3 phases = 4.14 kW.
If you want to charge your car with PV power only, your PV system must produce at least 4.14 kW of surplus power before charging can even start. In the winter months or with smaller systems this is rarely the case, so the solar power produced cannot be used efficiently.
To get around this, the car can also be charged on 1 phase. This results in a much lower minimum charging power of 6 A * 230 V * 1 phase = 1.38 kW. A PV surplus of this size is reached much more often, even in winter or with smaller PV systems.
This maximizes self-consumption and avoids longer charging pauses when the PV system temporarily provides less power than 3-phase charging requires.
How neoom Ai switches the charging station between 1-phase and 3-phase charging
neoom Ai continuously measures the available PV surplus power.
If a car is connected to a charging station controlled by neoom Ai and the optimization strategy "Solar" is selected in the neoom App (see image), neoom Ai decides, based on the available PV surplus power, whether the car is charged on 1 or 3 phases.
Example
- The chart shows a typical curve of available PV surplus power on a summer day.
- With switching from 3-phase to 1-phase charging, car charging can already start at 1.4 kW (shortly after 7 am).
- At 10:30 there is 4.2 kW of PV surplus and neoom Ai switches the charging station to 3-phase charging.
- When the PV surplus drops again at around 5 pm, it switches back to 1-phase charging.
- This way the available PV energy can also be used in the morning and evening.
Switching thresholds
- 1-phase charging starts at around 1.4 kW of surplus power and continues up to 4.6 kW of surplus power.
- If a surplus of at least 4.6 kW is available for at least 5 minutes, the charging station switches to 3-phase charging.
- It switches from 3-phase to 1-phase charging when PV power falls below 4.2 kW, i.e. when the surplus needed for 3-phase charging is not reached for more than 5 minutes.
Prioritizing PV surplus
In the neoom App you can define where the generated PV power is used first, for example whether the PV surplus goes to the battery or to the car charging station first. You can reach this setting via the menu icon on the neoom Ai overview page:
Only the PV surplus power intended for the charging station decides whether the charging station runs on 1 or 3 phases. This means: if the charging station is ranked after the battery, for example, the battery charging power is deducted from the total PV surplus power before deciding whether to charge on 1 or 3 phases.
Pausing the charging process
- To maintain communication between the charging system and the vehicle, charging is paused briefly during switching and then restarted.
- This pause ensures error-free switching.
- Switching takes about 2 minutes.
- Before switching from 1 to 3 phases, from 3 to 1 phase, or pausing (when there is not enough surplus even for 1-phase charging), the car is always charged for at least 5 minutes at minimum charging power (1-phase approx. 1.6 kW, 3-phase 4.6 kW). This prevents switching when less surplus is available for a short time (e.g. brief cloud cover).
- A charging pause lasts at least 5 minutes.
Phase switching cycles, number of phase switches and phase switching delay
- To protect the vehicle's onboard charger, only a limited number of phase switches per charging session is allowed as a safety feature.
- Changing the parameters for the maximum number of phase switches or the phase switching delay on neoom charging stations voids the warranty.