Braking System Battery Switching with Recuperative Voltage Equalization

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Solution Overview

Problem

High currents occur when switching to battery operation in braking systems, potentially damaging components due to significant voltage differences during vehicle electrical system failures.

Innovation Solution

A method that uses a switchable connection and the recuperation mode of an electric motor to reduce voltage differences by operating the motor in a recuperation mode when voltage thresholds are exceeded, and switching to battery operation when necessary, thereby minimizing harmful currents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the switchable connection is closed during battery operation, then the electric motor can be powered by the battery, but high currents occur that can place a strain on components

Engineering Contradiction:
Improvepower supply reliabilityVSAvoidhigh current strain on components
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies preliminary action by operating the electric motor in recuperation mode before closing the switchable connection. This pre-conditioning equalizes the voltage between the battery and the vehicle electrical system, preventing high current surges when the connection is subsequently closed. The motor generates voltage during recuperation, bringing it closer to battery voltage levels, thereby eliminating the voltage difference that would otherwise cause harmful currents.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent converts the potential harmful effect of voltage differences into a beneficial process. Instead of allowing high currents to flow directly when switching to battery operation, the system uses the voltage difference productively by operating the motor as a generator in recuperation mode. This converts what would be a harmful current surge into a controlled energy recovery process, protecting components while maintaining power supply reliability.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Object-affected harmful factors

If the electric motor is operated in recuperation mode, then the voltage difference is reduced, but this requires additional control logic and switching mechanisms

Engineering Contradiction:
Improvevoltage differenceVSAvoidcontrol logic and switching mechanisms
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent applies multi-functionality by using the electric motor for dual purposes: as a drive motor during normal operation and as a generator in recuperation mode. The same motor and existing control infrastructure serve both functions, eliminating the need for separate voltage equalization equipment. The switchable connection, already part of the hybrid power supply architecture, is utilized for both power routing and voltage equalization control.

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

Solution Approach 2:

The system applies self-service by using its own electric motor and existing control systems to perform the voltage equalization function. Rather than introducing external active components specifically for voltage matching, the patent leverages the motor's inherent ability to operate in generator mode, allowing the system to self-regulate voltage differences using resources already available within the braking system architecture.

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 approach significantly reduces the voltage difference and current flow when switching to battery operation, protecting components and ensuring reliable power supply to the braking system.

Implementation Method 1

the electric motor is operated in a recuperation mode

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4157686B1Method for operating a braking system
Publication Date: 2024.07.10 CONTINENTAL AUTOMOTIVE TECHNOLOGIES GMBH
  • EP4157686B1 patent drawingFigure 1
  • EP4157686B1 patent drawingFigure 2

AI summary

The invention relates to a method for operating a braking system, according to which method a switchable connection between two connection points is opened in normal operation, and a voltage difference across the switchable connection is reduced by recuperation before the connection is closed, which serves offsetting a malfunction in a vehicle electrical system. In this way, excess currents during closing of the switchable connection can be avoided.