Unbalanced Load Balancing Unit for EV Charging Infrastructure
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Solution Overview
Problem
High charging currents for electric vehicles strain the supply network, leading to excessive loading and unbalanced loads, which existing charging infrastructure struggles to manage effectively, often requiring reduction of charging currents to comply with maximum current-carrying capacity and unbalanced load limits.
Innovation Solution
A charging infrastructure arrangement with an unbalanced load compensation unit that balances the load across phase conductors by determining cumulative and local loads and applying equalizing currents, ensuring the maximum unbalanced load and current-carrying capacity are not exceeded, using a three-phase supply system with a neutral conductor and power electronics with a bridge circuit for optimal distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple charging points are connected to the grid at a single connection point and charged simultaneously with high charging currents, then the charging speed and productivity are improved, but the strain on the power grid and the unbalanced load increase excessively
Solution Approach 1:
The patent introduces a load balancing unit as an intermediary device between the charging points and the power grid. This unit actively monitors the load on each phase conductor and dynamically redistributes the charging load to maintain balance, thereby enabling high charging currents to be drawn simultaneously at multiple charging points without causing excessive strain or unbalanced load on the power grid.
Solution Approach 2:
The load balancing unit dynamically adjusts the distribution of charging load across phase conductors in real-time based on the current load situation. By continuously monitoring and actively redistributing the load, the system adapts to changing charging demands while maintaining balance, thus resolving the contradiction between high charging speed and grid strain.
2Object-affected harmful factors
If individual vehicles are charged with reduced charging current to comply with maximum current-carrying capacity limits, then the grid strain is reduced, but the charging speed and productivity decrease
Solution Approach 1:
The load balancing unit dynamically redistributes the total charging demand across available phase conductors based on their current load status. This dynamic load management allows multiple vehicles to charge simultaneously at optimal speeds without any single phase conductor exceeding its current-carrying capacity, thus maintaining both compliance and high charging productivity.
Solution Approach 2:
The system changes the distribution parameters of the charging load across different phase conductors in real-time. By adjusting which vehicles are connected to which phases and at what current levels, the load balancing unit ensures that the sum of loads on any phase does not exceed the maximum current-carrying capacity, while still allowing high charging currents to flow to individual vehicles when phases are available.
3Object-affected harmful factors
If different charging points are connected to different phase conductors to distribute load, then the unbalanced load is reduced, but the system complexity and device complexity increase
Solution Approach 1:
The load balancing unit serves multiple functions simultaneously: it monitors the load on each phase conductor, calculates the unbalanced load, actively redistributes charging demand, and provides information about available capacity to charging points. This multi-functional approach reduces unbalanced load without proportionally increasing system complexity, as a single device handles multiple tasks.
Solution Approach 2:
The load balancing unit continuously monitors the actual load on each phase conductor and uses this feedback information to dynamically adjust the distribution of charging load. This closed-loop feedback mechanism automatically maintains balance without requiring complex manual configuration or intervention, thereby reducing unbalanced load while keeping the control system relatively simple.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution balances the load on phase conductors, preventing peak loads and ensuring the unbalanced load at the connection point remains within permissible limits, allowing for higher and more even charging of multiple vehicles without overloading the external supply network.
Implementation Method 1
The unbalanced load compensation unit is designed to determine a cumulative load on each phase conductor of the three-phase supply system due to the sum of the AC charging points and/or a local load on the three-phase supply system due to each individual AC charging point
Data Source
Figure 1
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Figure 4~5
AI summary
The invention relates to a charging infrastructure arrangement for charging electric vehicles comprising a connection point (6) configured for connecting the charging infrastructure arrangement to an external supply network (8), comprising a three-phase supply system (7) with three phase conductors and a neutral conductor leading to the connection point (6), comprising at least one AC charging point (1-4) connected to at least one phase conductor of the three-phase supply system (7) and the neutral conductor, and comprising a load balancing unit (5) connected to the phase conductors and the neutral conductor of the three-phase supply system (7) via connecting conductors.wherein a maximum current-carrying capacity and/or a maximum unbalanced load are specified for the connection point (6) and wherein the unbalanced load balancing unit is configured to receive information about a cumulative load on each phase conductor of the three-phase supply system (7) due to the AC charging points (1-4) and/or a local load on the three-phase supply system (7) due to a charging current from each AC charging point (1-4) and to induce a balancing current between the phase conductors of the three-phase supply system (7) such that the maximum unbalanced load and/or the maximum current-carrying capacity are not exceeded at the connection point (6). Furthermore, the invention relates to an unbalanced load balancing unit (5) for a charging infrastructure arrangement and an operating method therefor.