In the following article, you’ll gain insights into the topic of unbalanced load and how the reev EMS can help minimize the associated risks.
What is unbalanced load?
Plug-in hybrids and HEVs (Hybrid Electric Vehicles) are often single-phase or dual-phase vehicles. This frequently leads to uneven load distribution across the phases, a phenomenon referred to as unbalanced load.
To address this, electricians often implement a technique called phase rotation. This involves varying the connection order of the phases across different charging stations.
Example:
1. Wallbox: L1, L2, L3
2. Wallbox: L2, L3, L1
3. Wallbox: L3, L1, L2
This rotation helps distribute the load more evenly across the phases. For instance, when three single-phase charging vehicles are connected, this setup ensures that L1, L2, and L3 are equally utilized.
However, phase rotation alone cannot provide complete control over unbalanced load—it only reduces it.
This is where our intelligent load management system, the reev EMS, comes in. The reev EMS detects the exact phase distribution on-site and monitors the charging power of each charging point in real time. This ensures continuous balancing of phase loads and guarantees grid stability at all times, regardless of the number or type of vehicles being charged.
With the reev EMS, you can ensure that your charging infrastructure is optimally utilized while maintaining grid stability even during high charging activity.
Why is unbalanced load a problem for charging infrastructure?
In Germany, the VDE-AR-N 4100 application guideline governs the permissible unbalanced load in low-voltage networks. According to this guideline, single-phase loads must not exceed 20 A, corresponding to a power limit of 4.6 kW. In Austria and Switzerland, this limit is 16 A, or 3.7 kW.
The reev EMS offers high flexibility in this context. During installation, customers can activate or deactivate unbalanced load monitoring and individually set the maximum allowable imbalance value. This ensures that the charging infrastructure complies with local regulations while maintaining optimal grid stability.
How the reev EMS helps avoid unbalanced load and reduce costs
The reev EMS ensures that available power is optimally distributed across charging points and that phase loads remain balanced. Through its intelligent load management, it not only prevents technical issues but also contributes to cost savings:
Efficient Grid Load Distribution: The reev EMS evenly distributes loads across all three phases, preventing grid overload and avoiding costly penalties from grid operators.
Cost Reduction Through Reduced Energy Loss: By minimizing energy losses caused by unbalanced load, it reduces energy consumption and increases efficiency.
Avoidance of Expensive Grid Upgrades: Balanced load distribution optimally utilizes existing grid capacity, saving you from costly upgrades and expansions of your infrastructure.
Reduced Maintenance and Longer Equipment Lifespan: By mitigating the risks of overheating and overloads, the reev EMS extends the lifespan of your equipment components, thereby lowering long-term maintenance costs.
Frequently Asked Questions (FAQ)
1. What type of load management does the reev EMS provide?
The reev Balancer supports both static and dynamic load management. Dynamic load management adjusts the charging power in real time based on grid conditions, ensuring optimal efficiency and stable phase loads.
2. Are there legal regulations on unbalanced load that operators must follow?
Yes, for example, in Germany, the VDE-AR-N 4100 sets specific limits for unbalanced load. The reev EMS helps operators comply with these regulations and maintain efficient, rule-compliant grid operations.