Parallel Battery Charge Current Control via Local Quality

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Solution Overview

Problem

In power storage systems with multiple secondary batteries connected in parallel, overcurrent of charge current can occur due to variations in charge states, leading to potential damage and inefficiencies.

Innovation Solution

A power storage system with at least two battery units connected in parallel, each equipped with a monitor device and a power storage control device that adjusts the charge current based on the charge state of each unit, including the use of an interruption device to prevent overcurrent by decreasing the charge current when a specific voltage value is reached, and sharing charge information between control devices to synchronize adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If multiple secondary batteries are connected in parallel for charging, then charging capacity is improved, but overcurrent of charge current occurs due to variations in charge states

Engineering Contradiction:
Improvecharging capacityVSAvoidovercurrent
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by providing individual constant current control circuits for each series connection battery block within the parallel configuration. Each control circuit independently monitors and regulates the charge current for its specific battery block based on its charge state, allowing different parts of the system (individual battery blocks) to have customized charge control characteristics tailored to their local conditions.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements dynamics by making the charge current value dynamically adjustable based on the charge state of each battery block. The control circuits continuously monitor voltage and current, and automatically adjust the charge current to prevent overcurrent conditions while maximizing charging capacity. The charge current is decreased when voltage reaches specific thresholds and increased when voltage is below thresholds.

Inventive Principle:
Principle #15Dynamics

2Productivity

If constant current charging is applied to all battery units, then charging efficiency is improved, but voltage variations cause overcurrent in some units

Engineering Contradiction:
Improvecharging efficiencyVSAvoidovercurrent
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by providing individual constant current control circuits for each series connection battery block within the parallel configuration. Each control circuit independently monitors and regulates the charge current for its specific battery block based on its charge state, allowing different parts of the system (individual battery blocks) to have customized charge control characteristics tailored to their local conditions.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent implements feedback by continuously monitoring the voltage and current of each battery block and using this information to adjust the charge current. The control circuits receive feedback signals from voltage detection circuits and automatically adjust the charge current accordingly - decreasing current when voltage reaches upper thresholds and increasing current when voltage is below thresholds, thereby preventing overcurrent while maintaining charging efficiency.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP2843751B1Power storage system, power storage control device and power storage control method
Publication Date: 2017.07.19 SONY GROUP CORP
  • EP2843751B1 patent drawingFigure 1
  • EP2843751B1 patent drawingFigure 2
  • EP2843751B1 patent drawingFigure 3

AI summary

There is provided a power storage system (100) including at least two battery units mutually connected in parallel, the battery units each including at least one cell (111) and at least one monitoring device (112) configured to monitor a charge state, at least one battery charger (102) configured to supply charge current to each of the battery units, and at least one power storage control device (120) configured to control a charge current value that is supplied to the battery units. The power storage control device is configured to decrease the charge current value in accordance with the charge state of each of the battery units.