Parallel Overvoltage Bypass for Series Energy Storage Racks

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Solution Overview

Problem

In the medium-voltage range, energy storage devices with a large number of components are unreliable due to high failure rates, making it difficult to manage faults and prevent overvoltage issues, which can lead to breakdowns and fires during charging or discharging.

Innovation Solution

An overvoltage protection system is implemented, featuring a circuit connected in parallel with energy storage modules or racks, equipped with voltage monitoring and components like diodes and electronic switches, which detects and mitigates overvoltage conditions by diverting energy around faulty modules, preventing potential differences from exceeding safe limits and maintaining system operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If a large number of energy storage cells are connected in series to achieve medium-voltage range, then the voltage capacity is improved, but the reliability deteriorates due to high failure rates of individual components

Engineering Contradiction:
Improvevoltage capacityVSAvoidsystem reliability
Core Design Contradiction:
Stress or pressureVSReliability

Solution Approach 1:

The energy storage system is divided into multiple energy storage modules, each with its own overvoltage protection circuit. This segmentation allows independent monitoring and protection of each module, preventing a single point of failure from compromising the entire system while maintaining the required voltage capacity through series connection of protected modules.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Overvoltage protection circuits are introduced as intermediary components between the series-connected energy storage cells. These protection circuits act as mediators that detect and respond to overvoltage conditions, isolating faulty cells and preventing voltage differences from exceeding safe limits, thereby maintaining system reliability while preserving voltage capacity.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If continuous monitoring of all energy storage cells is implemented to detect faults early, then the reliability is improved, but the device complexity increases due to the large number of components requiring monitoring

Engineering Contradiction:
Improvefault detection capabilityVSAvoidmonitoring system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Multiple monitoring functions are merged into integrated overvoltage protection circuits that are connected in parallel with each energy storage module. Each protection circuit combines voltage sensing, fault detection, and protective switching capabilities, reducing the overall system complexity compared to separate monitoring components for each cell while maintaining comprehensive fault detection capability.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If the system is shut down immediately upon detecting errors to ensure safety, then the reliability is improved, but the productivity deteriorates due to loss of operational time and redundancy switching

Engineering Contradiction:
Improvesafety assuranceVSAvoidoperational continuity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The overvoltage protection circuits incorporate dynamic response capabilities with adjustable thresholds and time constants. When faults are detected, the protection circuits can dynamically adjust their response based on the severity and type of fault, allowing the system to maintain operation under minor conditions while providing immediate protection for critical failures, thus balancing safety and operational continuity.

Inventive Principle:
Principle #15Dynamics

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The overvoltage protection system effectively prevents critical states and potential fires by identifying and isolating faulty components, allowing the energy storage device to continue operating safely during charging and discharging, even with faulty modules, thus enhancing reliability and reducing the risk of shutdowns.

Implementation Method 1

voltage monitoring and components like diodes and electronic switches, which detects and mitigates overvoltage conditions

Methodology Applied
Scientific EffectVoltage monitoring: Electric Field

Implementation Method 2

components like diodes and electronic switches, which detects and mitigates overvoltage conditions by diverting energy around faulty modules

Methodology Applied
Scientific EffectDiode rectification: Diode

Data Source

PatentEP4231492A1Over-voltage protection system for energy storage
Publication Date: 2023.08.23 M&P MOTION CONTROL & POWER ELECTRONICS GMBH

AI summary

The object of the invention is to create an overvoltage protection system for an energy storage device and a bypass solution for faulty components of the energy storage device.Overvoltage protection system for an energy storage device, wherein the energy storage device comprises at least one energy storage module (1) with energy storage cells connected in series, wherein the at least one energy storage module (1) can be arranged in a rack (2) or wherein one, two or more energy storage modules (1) form at least one rack (2), wherein at least two or more of the energy storage modules (1) are connected in series in a rack (2) or as a rack (2), characterized in that at least one of the energy storage modules (1) has an overvoltage protection circuit (6) or that a plurality of energy storage modules (1) jointly have an overvoltage protection circuit (6), wherein the overvoltage protection circuit (6) is connected in parallel to the at least one of the energy storage modules (1) or in parallel to the plurality of energy storage modules (1) or in parallel to the energy storage modules (1) of a rack (2).