EV Charging Point Authorization Using Building Current Bus Signals

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Solution Overview

Problem

The challenge is to provide an efficient and safe method for charging electric vehicles in private and commercial settings without requiring additional connections to the public power grid, while also preventing overloads at existing building connections.

Innovation Solution

The method involves using a current measuring device to continuously monitor the current flowing at the building connection and transmit this information via a network cable as a bus signal. This allows charging points to receive authorization to charge electric vehicles and to stop the charging process if an overload is detected, thereby preventing damage to the building connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If charging points are connected to the public power grid via additional house connections, then charging capacity and reliability are improved, but installation complexity and cost increase

Engineering Contradiction:
Improvecharging capacityVSAvoidinstallation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the charging load with the existing building electrical infrastructure by connecting charging points to the internal electrical distribution system rather than requiring separate utility connections. This combines multiple functions (building power distribution and EV charging) into a single integrated system, reducing installation complexity while maintaining charging capacity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The existing building electrical connection is made multi-functional by serving both the building's internal electrical loads and the EV charging points. The single house connection performs dual purposes: powering building systems and providing charging capacity, thereby improving reliability without requiring additional utility infrastructure.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of manufacture

If multiple charging points are connected to a single building connection, then installation effort is reduced, but risk of overcurrent and overload increases

Engineering Contradiction:
Improveinstallation effortVSAvoidovercurrent risk
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent implements a feedback mechanism where a control device continuously monitors the current drawn by each charging point and the total current at the building connection. Based on this real-time feedback, the control device dynamically adjusts or terminates charging operations to prevent overcurrent conditions, thereby enabling multiple charging points on a single connection without increasing overload risk.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The charging system transitions from a static, fixed-power configuration to a dynamic, adaptive system. The control device continuously adjusts the power distribution to charging points based on real-time monitoring of building connection capacity, ensuring optimal utilization without exceeding safe current limits. This dynamic adjustment allows multiple charging points while preventing harmful overcurrent conditions.

Inventive Principle:
Principle #15Dynamics

3Reliability

If charging current is continuously monitored and controlled, then safety and reliability are improved, but system complexity increases

Engineering Contradiction:
ImprovesafetyVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control device performs self-service by autonomously monitoring current levels and making decisions about charging termination or adjustment without requiring external intervention or complex centralized control systems. Each charging point essentially manages its own operation within the constraints set by the control device, reducing overall system complexity while maintaining high safety standards through continuous monitoring.

Inventive Principle:
Principle #25Self-service

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 enables secure and efficient charging of electric vehicles with minimal wiring effort, reducing the risk of overloads and protecting the building connection by allowing for real-time monitoring and adjustment of charging processes.

Implementation Method 1

a current measuring device continuously determines the current currently flowing at the building connection and sends information about this to the charging points by means of serial data transmission as a bus signal

Methodology Applied
Scientific EffectElectrical current measurement: Ohmmeter

Implementation Method 2

performing a charging process of the electric vehicle, wherein the charging process comprises providing the power transported from the building connection via the power cable to the electric vehicle as charging current

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP3939825B1Method for charging an electric vehicle
Publication Date: 2025.06.18 LADE GMBH
  • EP3939825B1 patent drawingFigure 1~3
  • EP3939825B1 patent drawingFigure 4
  • EP3939825B1 patent drawingFigure 5

AI summary

The invention relates to a method for charging an electric vehicle (100) at a charging point (102) of a set of charging points (102) via an electrical building connection supplied with mains voltage, wherein the charging points are connected to the electrical building connection (120) via a power cable (108) and to a release server (126) via a network cable (110), wherein a current measuring device (112) permanently determines the current currently flowing at the building connection (120) and sends information about this to the charging points (102) by means of serial data transmission as a bus signal via the network cable (110).