DC-DC Converter Operating Strategy for Vehicle Electrical Systems

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Solution Overview

Problem

Current methods for operating electrical systems in motor vehicles, particularly in multi-voltage networks, fail to optimize the service life of DC converters and batteries, leading to suboptimal usage and premature failure, which affects the reliability of automated or autonomous driving functions and results in unnecessary maintenance visits and wasted component lifespan.

Innovation Solution

A damage-dependent converter operating strategy is implemented, allowing for cost-effective use of energy stores and DC/DC converters by monitoring and adjusting the operating parameters based on the damage to both battery and converter, ensuring optimal service life through a software-based approach.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a fixed operating strategy is used for DC converters based on driving cycles, then the system is simple to operate, but the service life of battery and DC converter is reduced due to suboptimal usage

Engineering Contradiction:
Improveoperating strategy simplicityVSAvoidservice life of battery and DC converter
Core Design Contradiction:
Ease of operationVSDuration of action of stationary object

Solution Approach 1:

The patent applies dynamics by transitioning from a fixed operating strategy to a dynamic one that adapts in real-time. The control unit continuously monitors the actual state of charge of the battery and adjusts the converter's operating parameters accordingly, ensuring optimal service life extension under varying vehicle usage conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback by using the control unit to monitor the actual state of charge of the battery and compare it with the target state of charge. Based on this feedback, the control unit dynamically adjusts the converter's operating strategy, creating a closed-loop control system that optimizes component lifespan.

Inventive Principle:
Principle #23Feedback

2Ease of manufacture

If driving cycles are used to estimate vehicle usage, then the operating strategy can be predefined, but inaccuracy in usage estimation leads to suboptimal component usage and premature failure

Engineering Contradiction:
Improvepredefined operating strategyVSAvoidaccuracy of usage estimation
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies self-service by enabling the system to automatically determine its own operating strategy based on real-time monitoring of the battery's state of charge. The control unit independently adjusts converter operations without relying on external driving cycle estimates, allowing the system to adapt to actual usage patterns.

Inventive Principle:
Principle #25Self-service

3Loss of energy

If the converter operating strategy is not adapted to actual usage, then maintenance costs are reduced, but component lifespan is wasted and automated driving functions cannot be activated

Engineering Contradiction:
Improvewasted component lifespanVSAvoidactivation of automated driving functions
Core Design Contradiction:
Loss of energyVSProductivity

Solution Approach 1:

The patent applies preliminary action by proactively managing the battery state of charge to prevent future damage. The control unit continuously adjusts the converter's operation to maintain the battery within optimal charge ranges, preventing damage before it occurs and ensuring components are ready for automated driving functions.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3296144B1Method for operating an on-board network
Publication Date: 2020.04.29 ROBERT BOSCH GMBH
  • EP3296144B1 patent drawingFigure 1
  • EP3296144B1 patent drawingFigure 2
  • EP3296144B1 patent drawingFigure 3

AI summary

The invention relates to a method for operating an on-board electrical system (10) in a motor vehicle, wherein the on-board electrical system (10) comprises a DC-DC converter (30) and an energy storage device, wherein damage to the DC-DC converter (30) and damage to the energy storage device is determined during operation of the on-board electrical system (10), wherein a target damage profile is specified for both the DC-DC converter (30) and the energy storage device, and the on-board electrical system (10) is operated in such a way that the determined damages each take into account the associated target damage profiles.