Battery Contactor Protection Logic for Fusion Bonding Faults
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Solution Overview
Problem
Existing battery systems face issues with inrush currents and multiple fusion bonding of contactors due to reliance on software-based control, which can lead to operational failures and unsafe conditions.
Innovation Solution
A hardwired fusion bonding protecting module using an SR latch, comparator, and AND gate to control the negative electrode contactor based on the fusion and bonding status of the positive electrode contactor, ensuring safe operation by preventing multiple fusion bonding through logical control signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If software-based control is used to detect and respond to positive electrode contactor fusion bonding, then the system can identify fusion bonding conditions, but the negative electrode contactor may still close due to inrush current causing multiple fusion bonding
Solution Approach 1:
The patent applies preliminary anti-action by using a hardwired protection module that proactively prevents the negative electrode contactor from closing when positive electrode contactor fusion bonding is detected. The module monitors the voltage difference across the positive contactor and, upon detecting fusion bonding conditions (voltage difference below threshold), automatically generates a blocking signal to prevent negative contactor closure before inrush current can cause damage. This preemptive measure eliminates the harmful effect of inrush current without relying on software response time.
2Reliability
If hardwired protection module is implemented to prevent multiple fusion bonding, then operational safety is improved, but device complexity increases
Solution Approach 1:
The patent employs an intermediary approach by introducing a dedicated hardwired protection module that acts as a mediator between the positive and negative electrode contactors. This module independently monitors the positive contactor's voltage difference and automatically controls the negative contactor's switching operation without requiring software intervention. The intermediary structure simplifies the control logic by separating protection functions from main control software, actually reducing overall system complexity despite adding a dedicated protection component.
Solution Approach 2:
The patent applies mechanics substitution by replacing software-based control logic with a hardwired electrical protection module that uses voltage difference comparison and automatic signal generation. Instead of relying on software algorithms to detect fusion bonding and respond to inrush current conditions, the system uses an electrical circuit with voltage comparison functionality that directly generates control signals. This substitution eliminates software processing delays and provides more reliable, deterministic protection behavior.
3Reliability
If the negative electrode contactor is kept open during fusion bonding conditions, then multiple fusion bonding is prevented, but productivity and energy efficiency are reduced
Solution Approach 1:
The patent implements feedback by continuously monitoring the voltage difference across the positive electrode contactor and using this information to control the negative electrode contactor's switching state. When the voltage difference indicates fusion bonding (below threshold), the protection module generates a signal to keep the negative contactor open. When the voltage difference returns to normal (above threshold), the blocking signal is removed, allowing the negative contactor to close and resume normal operation. This feedback mechanism ensures the system remains productive while preventing multiple fusion bonding, automatically restoring functionality when safety conditions are met.
Data Source
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AI summary
A fusion bonding protecting module for controlling a negative electrode contactor connected between a negative electrode of a battery pack and a second output end according to fusion and bonding of a positive electrode contactor connected between a positive electrode of the battery pack and a first output end, including: an SR latch including a set terminal for receiving a fusion bonding sensing signal according to whether the positive electrode contactor is fused and bonded and a reset terminal for receiving a comparison signal according to a voltage difference between a first end and a second end of the positive contactor; and an AND gate for generating a compensation control signal by ANDing a logic control signal that is an inverted output of the SR latch and a control signal for controlling the negative electrode contactor.