Battery Module Semiconductor Switch for Thermal Runaway Bypass
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Battery electric systems face challenges in maintaining thermal regulation and propulsion during thermal runaway propagation (TRP) events, where an open-circuit condition in one battery cell can lead to rapid heat spread and substantial power loss, making it difficult to power critical loads and maintain cooling systems.
Innovation Solution
Integration of low-loss diodes or active semiconductor switches within battery modules to enable passive or active bypass of faulty cells, ensuring continued power supply to critical systems and maintaining limited propulsion functions during TRP events, with the option to connect battery packs in series for enhanced charging capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If active switching control is used to bypass faulty battery cells during TRP events, then thermal runaway propagation control is improved, but device complexity increases and reliability decreases due to potential switch failure under high inrush currents
Solution Approach 1:
The patent extracts the switching function from active control and implements it passively through diodes integrated into the battery module circuitry. This removes the need for complex active switching control while maintaining bypass functionality, thereby reducing device complexity and improving reliability during TRP events.
Solution Approach 2:
The diode-based bypass system operates autonomously without requiring external control signals. When a battery cell goes into open-circuit state during TRP, the diode automatically conducts to bypass the faulty cell, eliminating the need for complex control systems and reducing points of failure.
2Reliability
If bypass switches are used to isolate open-circuit battery cells, then thermal runaway propagation is controlled, but power loss increases and propulsion capability is reduced
Solution Approach 1:
The patent implements bypass functionality at the individual battery module level rather than requiring system-wide bypass. This localized approach allows only the specific module experiencing TRP to be bypassed, while the remainder of the battery system continues to provide power, thus minimizing power loss and maintaining propulsion capability.
Solution Approach 2:
The battery system is segmented into multiple independent modules, each with its own bypass diode. This segmentation allows selective bypassing of individual modules during TRP events, enabling the system to maintain power output from healthy modules while isolating only the affected segment.
3Object-affected harmful factors
If mid-pack fuses are used for TRP protection, then thermal runaway propagation is limited, but productivity decreases due to substantial reduction in battery power and loss of propulsion
Solution Approach 1:
The bypass diodes are pre-integrated into the battery module circuitry during manufacturing, positioned and configured to automatically activate when needed. This preliminary preparation ensures immediate response during TRP events without requiring additional control systems or post-fault configuration, maintaining both safety and productivity.
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 solution effectively manages TRP events by providing maximum available DC bus voltage to critical loads and ensuring limited propulsion, while minimizing power loss and maintaining thermal regulation, thus preventing complete system failure.
Implementation Method 1
The semiconductor switch, which is connected in parallel with the one or more battery cells within the respective battery module, is configured to conduct an electrical current during a TRP event
Implementation Method 2
Aspects of the present disclosure include integrating diodes, e.g., Schottky diodes or other low voltage drop/low-loss diodes, into the individual battery modules to enable passive bypass of the particular battery module experiencing the open-circuit condition
Data Source
AI summary
A rechargeable energy storage system (RESS) includes a battery controller and battery modules, each respective module having battery cells, a cell sense board, and a semiconductor switch. The switch is connected in parallel with the cells within the respective module, and configured to conduct an electrical current during a thermal runaway propagation (TRP) event in which one or more cells is in an open-circuit state. This action bypasses the module and enables electrical components to be powered by the RESS during the TRP event. A battery electric system includes a direct current (“DC”) voltage bus, an electrical component connected thereto, the battery controller, and the RESS. A method for constructing the RESS includes connecting a respective semiconductor switch in parallel with the at least one battery cell of each respective one of the multiple battery modules, and electrically connecting the multiple battery modules together to construct the RESS.