EV Battery Disconnect Control for Collision Safety

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Solution Overview

Problem

In electric vehicles, existing charge/discharge control devices consume extra power to supply electricity to ECUs, reducing charging efficiency, especially when the vehicle is in an ignition-off state and charged, making it difficult to detect collisions without power consumption.

Innovation Solution

A charge/discharge control device with a contactor switching control unit that disconnects the high-voltage battery when the vehicle speed reaches a certain threshold, using a contactor to disconnect the electrical connection between the high-voltage battery, inverter, and charging port, thereby preventing extra power consumption during collision detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electric power is supplied to the ECU in ignition off state and charged state to enable collision detection, then collision detection capability is improved, but extra electric power is consumed and charging efficiency decreases

Engineering Contradiction:
Improvecollision detection capabilityVSAvoidcharging efficiency
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent extracts the collision detection function from the main ECU and implements it independently using a separate sensor and dedicated processing logic. This allows collision detection to operate without requiring continuous power supply to the main ECU, thereby maintaining detection capability while eliminating extra power consumption during normal charging operations.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system performs preliminary action by equipping the vehicle with a dedicated collision detection sensor that remains functional independently of the main ECU power state. This preliminary preparation ensures that collision detection capability is already in place before ignition is turned off, eliminating the need to supply power to the main ECU for detection purposes during charging.

Inventive Principle:
Principle #10Preliminary action

2Object-affected harmful factors

If the contactor is turned off to disconnect the high-voltage battery when vehicle speed exceeds the threshold, then safety is improved by preventing electric shock, but charging operation is interrupted

Engineering Contradiction:
Improveelectric shock riskVSAvoidcharging efficiency
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The system implements feedback by continuously monitoring vehicle speed through the wheel speed sensor and automatically controlling the contactor switching based on the detected speed threshold. When the vehicle moves beyond the safe threshold, the system feedbacks this information to the contactor control unit, which then disconnects the high-voltage battery to prevent electric shock risk, ensuring safety through real-time monitoring and automatic response.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4056403A1Charge/discharge control device with a disconnect capability for disconnecting a high-voltage battery from the motor if a vehicle speed threshold is exceeded
Publication Date: 2022.09.14 SUZUKI MOTOR CORP
  • EP4056403A1 patent drawingFigure 1
  • EP4056403A1 patent drawingFigure 2
  • EP4056403A1 patent drawingFigure 3

AI summary

[Obj ect] Provided is a charge/discharge control device capable of electrically disconnecting a high-voltage battery by detecting a collision without consuming extra electric power even in an ignition off state and a charged state. [Solution] A charge/discharge control device includes: a high-voltage battery 4 which is a main power supply; an inverter 3 which drives a motor 2 by receiving electric power supplied from the high-voltage battery 4; a negative electrode side contactor 41 and a positive electrode side contactor 42 which connect and disconnect an electrical connection between the high-voltage battery 4 and the inverter 3; a normal charge contactor 62 which connects and disconnects an electrical connection between the high-voltage battery 4 and a normal charging connector 6; a negative electrode side quick charge contactor 71 and a positive electrode side quick charge contactor 72 which connect and disconnect an electrical connection between the high-voltage battery 4 and a quick charging connector 7; and a contactor switching control unit 5 which turns off the contactor if a speed of a vehicle 1 is equal to or faster than a first vehicle speed when electric power is supplied from an external power supply to the high-voltage battery 4.