Battery Branch Reconfiguration for Fault-Tolerant Energy Storage

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Solution Overview

Problem

Existing energy storage systems suffer from reduced operating efficiency and resource waste when a component, such as a battery pack or string-level converter, fails, causing the entire battery string to stop functioning.

Innovation Solution

The system incorporates a control circuit and switch units to reroute energy storage branches, allowing non-faulty components to charge or discharge faulty branches, and switch balancing converters to alternate modes for efficient operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If one battery pack or string-level converter fails in a battery string, then the entire battery string stops operating, but this causes resource waste and reduced system reliability

Engineering Contradiction:
Improvesystem reliabilityVSAvoidoperating efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent divides the energy storage system into multiple independent energy storage branches, where each branch contains its own battery string and string-level converter. This segmentation allows individual branches to operate independently, so that a failure in one branch does not affect other branches, thereby maintaining system reliability and operating efficiency despite component failures.

Inventive Principle:
Principle #1Segmentation

2Reliability

If the system uses multiple independent energy storage branches with switch units, then system reliability improves when components fail, but device complexity increases

Engineering Contradiction:
Improvesystem reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges multiple energy storage branches into a unified system through shared DC buses and control circuits. The switch units enable dynamic reconfiguration of branches, allowing the system to maintain reliability through redundancy while managing complexity through integrated control and shared infrastructure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The string-level converters are designed with multi-functionality, serving both as power conversion devices and as controllable switches for branch reconfiguration. This universal design reduces the need for separate switching components, thereby managing device complexity while maintaining system reliability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4322371B1Energy storage system
Publication Date: 2025.09.03 HUAWEI DIGITAL POWER TECH CO LTD
  • EP4322371B1 patent drawingFigure 1
  • EP4322371B1 patent drawingFigure 2
  • EP4322371B1 patent drawingFigure 3

AI summary

An energy storage system, is to improve operating efficiency and system reliability that exist when a component in the energy storage system is faulty, and avoid a waste of resources. The energy storage system includes a plurality of energy storage branches, at least one switch unit, and a control circuit. Each of the energy storage branches includes a first bus, a string-level converter, and a battery string that are sequentially connected in series, a plurality of balancing converters, and a shared bus. The battery string includes a plurality of battery units connected in series, and each of the battery units includes one battery pack. The battery pack is connected to an input side of one corresponding balancing converter, and output sides of the plurality of balancing converters are separately connected to the shared bus.