Power Distribution Strategies for VOOL 22 kW AC EV Charging
Introduction
To accommodate multiple simultaneous users and maximize infrastructure efficiency, VOOL employs two key power management strategies for its EV chargers: Equal Power Sharing and Prioritized Power Sharing.
These strategies are designed to ensure safe, efficient, and flexible charging based on available electrical capacity while meeting technical charging requirements, including the minimum current threshold of 6 amps per phase required for EVs to begin charging.
Technical Background
VOOL’s standard chargers operate up to 22 kW AC, using a 3-phase 400 V, 32 A
configuration. These chargers are suitable for both private and public applications and with load management controller (LMC) support smart load management based on system limitations.
Equal Power Sharing
Equal Power Sharing is a method where the total available site power is distributed evenly across all actively charging vehicles. As new vehicles are plugged in or disconnected, the system automatically recalculates and redistributes the available power among the active chargers.
In cases where the total power is insufficient to supply every vehicle with three-phase charging above the 6A minimum, VOOL’s system can dynamically adjust the number of phases assigned to each vehicle. The system will reduce the number of phases allocated to vehicles to allow more cars to charge.
If the system reaches its limit and cannot allocate power across all connected vehicles under Equal Power Sharing, vehicles that cannot begin charging will be switched to the Prioritized Power Sharing approach, where they will join the charging queue in the order they were plugged in.
Example Scenario
At a charging site with 24 A available, there are three vehicles connected:
EV1: The system assigns 3-phase charging at 8 A.
EV2: The system assigns 3-phase charging at 8 A.
EV3: The system assigns 3-phase charging at 8 A.
Prioritized Power Sharing (Fixed FCFS Model)
In VOOL’s Prioritized Power Sharing system, power is allocated to chargers based on the order in which vehicles are connected. This First-Come, First-Served (FCFS) model assigns full charging power (up to 22 kW) to the first vehicle, then the next, and so on—provided that at least 6A per phase is available for each subsequent charger.
If a new vehicle connects and the remaining available power is not sufficient to meet the minimum required to start charging, it will remain in a waiting state until enough power is freed (e.g., when another vehicle finishes charging or disconnects).
Example Scenario
At a site with 45 A available, the system will allocate power as follows:
EV1 (1st vehicle): Receives 32 A (full capacity).
EV2 (2nd vehicle): Receives the remaining 13 A.
EV3 (3rd vehicle): Receives no power initially, as there is not enough capacityleft to provide the minimum 6A per phase. It must wait until one of the other EVs disconnects.
Conclusion
VOOL’s 22 kW AC charging systems offer flexible power sharing capabilities tailored
for diverse environments—from shared public chargers to private fleet installations. By applying Equal Power Sharing with adaptive phase control or Fixed Prioritized Sharing, VOOL ensures efficient energy use and reliable charging performance under varying electrical conditions.
These strategies enable better charger availability and user experience, while
remaining compliant with the technical limits imposed by EVs and grid infrastructure. Electric Vehicle Charger Phase Switching with Load Management Integration Overview VOOL EV chargers are equipped with intelligent phase switching functionality, directed by our proprietary Load Management Controller (LMC). This ensures optimal power usage and grid protection by dynamically adjusting how the charger operates based on real-time power availability and usage.
Types of Phase Switching
We offer two types of phase switching solutions for EV charging systems:
1. Regular (dynamic) Phase Switching
This mode is used during active charging:
Charging begins in three-phase mode when power availability is sufficient (≥6A per phase).
If the LMC detects that one or more phases cannot supply at least 6A, it instructs the charger to switch to two-phase or single-phase mode, depending on vehicle and available capacity.
The charger follows the LMC’s command, ensuring safe, uninterrupted charging without overloading any phase. This real-time control helps prevent power outages and ensures maximum usage of the available energy infrastructure.
2. Smart Pre-Charge Phase Selection
This more intelligent mode is used before charging starts, especially for 1-phase or 2-phase EVs:
The LMC assesses current load conditions across all phases.
It determines which phase (or combination of phases) is least loaded and instructs the charger to use those for the session.
The charger follows the LMC’s phase selection command when the session begins.
This reduces phase imbalance and ensures fair load distribution across
the grid or building.
Role of the Load Management Controller (LMC)
The LMC acts as the intelligent controller for all charging activity:
Continuously monitors load on all phases.
Communicates with every connected charger.
Makes centralized decisions about current limits and which phase(s) each charger should use.
Provides both safety and load efficiency for entire buildings or networks.
Chargers do not make autonomous switching decisions — all phase selection and switching is directed by the LMC.