Battery Management Unit Current Balancing for Parallel Cells
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Solution Overview
Problem
Batteries of different capacities or materials connected in parallel experience bias and circulating currents due to internal resistance differences, leading to inconsistent state of charge and reduced cycle life.
Innovation Solution
A method and apparatus for real-time current adjustment in battery management units, balancing currents across parallel branch circuits by detecting and adjusting current values based on internal resistance and preset values, using adjustable resistors or DC/DC chargers to stabilize input and output currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If batteries of different capacities or materials are connected in parallel for use, then the battery system can provide higher power and greater flexibility, but bias current and circulating current are caused due to internal resistance differences, resulting in inconsistent state of charge and reduced service life
Solution Approach 1:
The patent implements a feedback control mechanism where the battery management unit continuously monitors the current values of each parallel branch circuit and dynamically adjusts the current distribution based on real-time measurements. This closed-loop feedback system ensures that batteries of different capacities or materials can operate in parallel while maintaining balanced current distribution, preventing bias and circulating currents that would otherwise reduce service life.
Solution Approach 2:
The patent dynamically changes the operating parameters (current values) of each parallel branch circuit based on the specific characteristics of connected batteries. By adjusting current distribution according to each battery's capacity and internal resistance, the system optimizes power output while preventing harmful current imbalances, allowing flexible battery configurations without compromising reliability.
2Adaptability or versatility
If batteries of different capacities or materials are connected in parallel for use, then the battery system can accommodate different battery types and capacities, but inconsistent state of charge develops due to internal resistance differences, causing bias current and circulating current
Solution Approach 1:
The battery management unit continuously monitors current values in each parallel branch and uses feedback control to detect and correct imbalances. This real-time monitoring and adjustment prevents the development of inconsistent state of charge that would lead to bias and circulating currents, enabling the system to accommodate different battery types and capacities safely.
Solution Approach 2:
The battery management unit acts as an intermediary between batteries of different characteristics, mediating the current distribution to prevent direct harmful interactions. By controlling the current flow through each branch based on real-time measurements, the management unit eliminates bias and circulating currents while maintaining the ability to connect diverse battery configurations.
3Reliability
If real-time current monitoring and adjustment is implemented in battery management units, then bias and circulating currents are controlled and battery service life is extended, but device complexity increases due to additional monitoring and control circuitry
Solution Approach 1:
The battery management unit is designed to perform multiple functions: monitoring current values, detecting imbalances, calculating appropriate current adjustments, and controlling current distribution. By consolidating these functions into a single multi-functional device, the patent reduces overall system complexity while achieving the goal of extending battery service life through real-time current management.
4Stability of the object's composition
If current values are dynamically adjusted in each parallel branch circuit, then consistent state of charge is maintained and harmful currents are eliminated, but manufacturing complexity increases due to additional control mechanisms
Solution Approach 1:
The patent employs feedback control where the battery management unit continuously monitors current values and automatically adjusts them to maintain consistent state of charge across all parallel branches. This automated feedback mechanism eliminates the need for complex manual balancing procedures, making the system easier to manufacture and deploy while ensuring stable operation and eliminating harmful currents.
Data Source
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AI summary
Embodiments of the present invention provide a method and an apparatus for battery management and a battery-powered device, which relate to the field of communications technologies and can effectively control an adverse impact resulting from a bias current and a circulating current that are caused when batteries or battery groups of different capacities or different materials are directly connected in parallel for use. The method is used for management over two or more than two batteries or battery groups connected in parallel on a circuit, a branch circuit where each battery or battery group connected in parallel is located forms one parallel branch circuit, and the method includes: detecting whether a current value on a target parallel branch circuit is greater than a preset current value; and when the detected current value on the target parallel branch circuit is greater than the preset current value, adjusting the current value on the target parallel branch circuit so that the current value on the target parallel branch circuit is smaller than or equal to the preset current value, thereby performing management over batteries connected in parallel.