Parallel Battery Pack Power Control for Resistance Imbalance
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Solution Overview
Problem
In parallel multi-pack systems, battery packs with low resistance are prone to overcharge or overdischarge due to increased pack power, which can compromise safety and reliability.
Innovation Solution
A power control apparatus and method that includes sensor units to measure operation characteristics, a multi-pack management unit to determine pack resistances and available powers, and a power management unit to adjust total power, ensuring the pack power of low-resistance battery packs aligns with minimum available power, thereby preventing overcharge or overdischarge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the total power of the parallel multi-pack system is determined based on the minimum power among battery packs multiplied by the number of packs, then the system can provide high total power output, but battery packs with low resistance will experience overcharge or overdischarge
Solution Approach 1:
The invention changes the parameter used for total power calculation from minimum power to minimum available power. By determining available power based on resistance values and adjusting the total power calculation formula to Ptotal = min(Pavailable,k) × n, the system ensures that battery packs with low resistance do not receive excessive power that would cause overcharge or overdischarge, while still maximizing the total power output capability of the parallel multi-pack system
Solution Approach 2:
The invention introduces a feedback mechanism where the management apparatus continuously monitors the resistance values of individual battery packs and adjusts the total power determination accordingly. By calculating available power based on real-time resistance measurements and using this information to set the system's total power limit, the system dynamically adapts to prevent overcharge or overdischarge of low-resistance packs while maintaining high power output
Data Source
AI summary
Disclosed is an apparatus and method for controlling power of a parallel multi pack system. The power control apparatus includes first to nth sensor units measuring operation characteristic values of first to nth battery packs connected in parallel; a power management unit controlling a power consumed in a load or a power provided by a charging device; and a multi pack management unit that: determines a pack resistance of each of the battery packs based on the operation characteristic value of each battery pack received from the sensor units, determines a minimum available power among available powers respectively corresponding to the pack resistances of the battery packs, determines a total power of the parallel multi pack system so the pack power of a battery pack having a lowest pack resistance becomes identical to the minimum available power, and transmit the determined total power to the power management unit.