Balancing Converter Reconfiguration in Faulted Battery Strings

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Solution Overview

Problem

Energy storage systems face inefficiencies and resource waste when a component, such as a battery pack or string-level converter, becomes faulty, causing the entire battery string to stop operating and non-faulty components to be idle.

Innovation Solution

The system incorporates multiple energy storage branches with switch units and a control circuit that allows for rerouting of power between branches, enabling a faulty branch to be charged or discharged using a non-faulty one, and adjusting converter modes to isolate faulty components, thus preventing waste and improving reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If one battery pack or string-level converter fails, then the entire battery string stops operating, but this causes non-faulty battery packs to become idle and resources to be wasted

Engineering Contradiction:
Improvesystem reliabilityVSAvoidoperating efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system divides the battery string into multiple independently controllable battery packs, each with its own balancing converter. This segmentation allows faulty battery packs to be isolated while non-faulty ones continue to operate, preventing the entire string from stopping due to a single failure point.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

When a battery pack or string-level converter fails, the control circuit identifies the faulty component and isolates it from the system. The balancing converters of non-faulty battery packs are then reconfigured to operate independently, recovering their productivity while the faulty component is effectively discarded from the operational chain.

Inventive Principle:
Principle #34Discarding and recovering

2Reliability

If the entire battery string stops due to a single faulty component, then system reliability is maintained through strict operational standards, but resource utilization deteriorates as non-faulty components become idle

Engineering Contradiction:
Improveoperational reliabilityVSAvoidenergy waste
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The system dynamically reconfigures the operational topology based on real-time fault detection. When a battery pack or string-level converter fails, the control circuit automatically adjusts the working mode of balancing converters from series operation to independent parallel operation, allowing the system to adapt its structure to maintain reliability while minimizing energy waste.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The control circuit changes the operational parameters of balancing converters based on system status. Non-faulty balancing converters switch from operating in a coordinated series mode to independent operation mode, changing their working parameters to maintain system reliability while continuing to utilize available energy resources effectively.

Inventive Principle:
Principle #35Parameter changes

3Object-affected harmful factors

If non-faulty battery packs are isolated due to a faulty component, then system safety is improved, but the quantity of operational components decreases

Engineering Contradiction:
Improvefault propagation preventionVSAvoidnumber of operational battery packs
Core Design Contradiction:
Object-affected harmful factorsVSQuantity of substance

Solution Approach 1:

The control circuit extracts and isolates only the faulty battery pack or string-level converter from the system while leaving non-faulty battery packs operational. This selective extraction prevents fault propagation to healthy components while maintaining the maximum possible quantity of operational battery packs.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The balancing converters are designed with multi-functionality, capable of operating in both coordinated series mode and independent parallel mode. This universality allows them to adapt their function based on system needs, maintaining safety by isolating faults while preserving the operational capacity of non-faulty battery packs.

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

Data Source

PatentEP4068564B1Energy storage system
Publication Date: 2023.10.04 HUAWEI DIGITAL POWER TECH CO LTD
  • EP4068564B1 patent drawingFigure 1
  • EP4068564B1 patent drawingFigure 2
  • EP4068564B1 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.