Battery Management System with Cell Isolation and Bypass
Solution Overview
Problem
Existing battery management systems for light electric vehicles fail to effectively manage the stress on battery cells, leading to reduced performance and lifespan, especially under heavy loads, and do not efficiently handle intermittent charging conditions from photovoltaic arrays under low light conditions.
Innovation Solution
A battery management system comprising a host controller and multiple battery management units, where each unit includes a battery cell, an isolation element, and a bypass element, allowing for dynamic control of cell activation and deactivation to balance stress and optimize recovery periods, and incremental activation to manage voltage and reduce inrush currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a battery operates under constant heavy load, then power output is maintained, but battery lifespan and performance deteriorate
Solution Approach 1:
The patent implements periodic action by cycling battery cells through active and isolated states. The host controller periodically isolates individual cells using isolation elements, allowing them to rest and recover while maintaining overall battery pack power output through remaining active cells. This periodic isolation prevents continuous stress accumulation, thereby extending battery lifespan while maintaining power delivery capability.
Solution Approach 2:
The patent divides the battery pack into multiple independently controllable cell groups, each with its own isolation element and bypass element. This segmentation allows selective isolation of specific cells experiencing stress or degradation, enabling targeted recovery without affecting the entire battery pack. The segmented architecture facilitates differential management of individual cells based on their specific conditions.
2Speed
If additional motor speed controller is added to respond to throttle demands, then vehicle performance improves, but system weight and cost increase
Solution Approach 1:
The patent makes the battery management system multi-functional by enabling it to perform both traditional battery management tasks and motor speed control functions. The host controller manages battery cell isolation and bypass operations while also responding to throttle system demands, effectively replacing the need for a separate motor speed controller. This universal approach reduces component count, system weight, and overall cost while maintaining performance.
Solution Approach 2:
The patent merges the motor speed control function with the battery management system. The host controller integrates both the battery management unit and motor control capabilities, combining previously separate functions into a single unified system. This consolidation eliminates redundant components and reduces system complexity, particularly benefiting light electric vehicles where weight reduction is critical.
3Use of energy by moving object
If photovoltaic array operates under lower light conditions, then energy capture is limited, but battery charging requirement remains
Solution Approach 1:
The patent implements dynamic voltage management to adapt to varying photovoltaic output conditions. The host controller dynamically adjusts the number of active battery cells based on the available solar energy, isolating cells when photovoltaic output is insufficient and activating them when energy availability increases. This dynamic response ensures reliable charging across varying light conditions by optimizing the match between supply and demand.
Solution Approach 2:
The patent changes the electrical parameters of the battery system by adjusting voltage and current levels through cell isolation and bypass operations. When photovoltaic output is limited, the system modifies operating parameters to match the reduced energy input, ensuring stable charging. This parameter adaptation allows the system to maintain reliability across different illumination conditions.
4Device complexity
If cell bypass system is implemented, then component count is reduced, but control complexity increases
Solution Approach 1:
The patent implements self-service through automated controller management of the bypass system. The host controller automatically monitors battery cell conditions and autonomously activates or isolates cells based on real-time status, eliminating the need for manual intervention. This automation handles the control complexity internally while presenting a simplified interface to the user, reducing component count without sacrificing control capability.
Data Source
AI summary
A battery management system can be provided which can include a plurality of battery management units connected in series and a host controller. Each battery management unit can include a battery cell, an isolation element, and at least one bypass element. The isolation element is connected with the battery cell in series, and the battery cell is isolated by turning off the isolation element. The bypass elements can be in parallel connection with the battery cell and isolation element, and the battery cell is bypassed by turning on the bypass element. A battery management method can include: activating the battery cell of the battery management unit by turning on the isolation element and turning off the bypass elements of the battery management unit; and deactivating the battery cell of the battery management unit by turning off the isolation element and turning on the bypass elements of the battery management unit.