Parallel Battery Charging Control for SOC and Voltage Imbalance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As the number of batteries connected in parallel increases, current imbalances due to differences in parameters such as voltage, internal resistance, and self-discharge rate can lead to safety hazards and reduced performance in energy storage systems and electric vehicles, necessitating effective charging control methods to prevent these issues.
Innovation Solution
A charging control method that differentiates based on whether the battery with the smallest State of Charge (SOC) or voltage is connected in parallel, using SOC or voltage differences to determine charging strategies, ensuring balanced charging and preventing current imbalances by controlling the connection of batteries to the system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If multiple batteries are connected in parallel to increase system capacity, then the energy storage capacity and performance of the system are improved, but current imbalance and safety hazards occur due to parameter differences among batteries
Solution Approach 1:
The patent applies preliminary action by determining the connection sequence of batteries before actual parallel connection occurs. The control device calculates SOC differences and voltage differences in advance, and establishes a predetermined connection sequence that prevents current imbalance from occurring in the first place, rather than correcting it after it arises.
Solution Approach 2:
The patent utilizes parameter changes by dynamically monitoring and comparing key parameters (SOC and voltage) of each battery. Based on the real-time parameter values, the control device adjusts the connection sequence and charging control strategies, changing the operational parameters to maintain current balance while maximizing system capacity utilization.
2Adaptability or versatility
If batteries with different parameters are connected in parallel, then system flexibility and adaptability are improved, but current imbalance and performance degradation occur
Solution Approach 1:
The patent applies local quality by implementing differentiated charging control strategies for different batteries based on their individual characteristics. Each battery receives customized charging control according to its SOC and voltage levels, allowing the system to accommodate batteries with different parameters while maintaining overall charging efficiency through localized optimization.
3Device complexity
If charging control is not implemented, then system complexity is reduced, but safety hazards and battery damage occur due to current imbalance
Solution Approach 1:
The patent implements feedback mechanisms by continuously monitoring the SOC and voltage of each battery during charging operations. The control device receives real-time data from all batteries, compares their parameters, and adjusts the connection sequence and charging control accordingly, creating a closed-loop system that prevents safety hazards while maintaining manageable complexity.
Data Source
AI summary
Provided are a charging control method for battery system, and a charging control apparatus. The charging control method includes: under a condition that a battery with a smallest SOC in N batteries has been connected in parallel to the battery system, performing charging control on the battery system based on a difference between a SOC of a first battery not yet connected in parallel to the battery system and a SOC of a second battery already connected in parallel to the battery system; or under a condition that the battery with the smallest SOC in the N batteries has not been connected in parallel to the battery system, performing charging control on the battery system based on a difference between a voltage of a third battery and a voltage of a fourth battery.