Priority Load Switching for Vehicle Power Failure Control

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Solution Overview

Problem

In-vehicle power systems face reliability issues due to high dependence on DC/DC converters, which are expensive and large, and insufficient battery capacity can prevent the continuous operation of high-priority loads during power failures.

Innovation Solution

A power switching control system that connects multiple power sources and loads in parallel, using switches and sensors to manage power distribution, ensuring that high-priority loads receive power even during power failures by disconnecting lower-priority loads and optimizing battery discharge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a DC/DC converter is used to adjust power from sub power to auxiliary loads, then power distribution control is achieved, but system reliability decreases and cost increases due to high dependence on the converter

Engineering Contradiction:
Improvepower distribution controlVSAvoidsystem reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent extracts the power conversion function from the DC/DC converter by directly connecting battery positive terminals to load positive terminals through switching elements. This eliminates the converter from the power path, allowing power distribution control without depending on the converter, thereby improving reliability while maintaining operational control.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces switching elements (transistors or MOSFETs) as intermediaries between the battery and loads to control power distribution. These switching elements replace the DC/DC converter's control function, enabling precise power management without the converter's single point of failure, thus resolving the contradiction between control capability and system reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If a DC/DC converter is used for power adjustment, then power distribution is controlled, but system size and cost increase

Engineering Contradiction:
Improvepower distribution controlVSAvoidsystem size
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The patent removes the DC/DC converter from the system by directly connecting battery terminals to loads through switching elements. This extraction eliminates the converter's physical volume while maintaining power distribution control through the switching elements, directly resolving the contradiction between control capability and system size.

Inventive Principle:
Principle #2Taking out (Extraction)

3Duration of action of moving object

If battery remaining capacity is insufficient, then power supply to high-priority loads cannot be maintained, but extending discharge time is needed for safe evacuation

Engineering Contradiction:
Improvedischarge timeVSAvoidpower supply continuity
Core Design Contradiction:
Duration of action of moving objectVSReliability

Solution Approach 1:

The patent implements dynamic power distribution by continuously monitoring battery remaining capacity and adjusting the power supply to different loads accordingly. When capacity is sufficient, all loads operate normally; when capacity becomes insufficient, the system dynamically switches to supply only high-priority loads, extending discharge time while maintaining power supply reliability for critical functions throughout the evacuation period.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system performs preliminary assessment of battery capacity and pre-plans power distribution strategies. By monitoring capacity levels in advance and switching to emergency mode before complete depletion, the system ensures continuous power supply to high-priority loads throughout the evacuation period, resolving the contradiction between extended discharge time and power supply continuity.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4148933B1Power switching control system
Publication Date: 2024.02.21 YAZAKI CORP
  • EP4148933B1 patent drawingFigure 1
  • EP4148933B1 patent drawingFigure 2
  • EP4148933B1 patent drawingFigure 3~4

AI summary

A power switching control system (10), includes a switching unit (11, 12, 13, 14, 15) configured to switch connection and disconnection between loads (IL1, IL2, IL3) set with operation priorities and powers (2, 3, 102) supplying powers to the loads, the loads and the powers being connected to a power supply path (8G); a power failure detection unit (31, 32) detecting a power failure caused by an abnormality on a power supply side or a load side; and a control unit (30) controlling the switching unit. When the power failure detection unit detects the power failure, and remaining capacities, charging rates, or voltages of the plurality of powers are less than, or equal to or less than predetermined thresholds, the control unit disconnects the loads from the power supply path by the switching unit in an order from one of the loads with a lowest operation priority of the operation priorities to gradually decrease supply currents from the powers to the loads.