Meshed Energy Storage Control for Fault-Tolerant Grid Integration

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Solution Overview

Problem

Existing electric power transmission systems face challenges in monitoring and controlling complex energy storage and reactive power compensation due to their large number of components, which complicates scalability and fault tolerance.

Innovation Solution

A support system for AC power transmission systems featuring a meshed topology with interconnected energy storage units and STATCOM devices, utilizing multiple control signal connections to relay control signals efficiently and redundantly, allowing for autonomous forwarding of control signals and reduced delay in high-priority message propagation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a point-to-point communication or strict series connection is used between storage units, then the control structure is simple, but the redundancy and fault tolerance are insufficient

Engineering Contradiction:
Improvefault toleranceVSAvoidcontrol structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control system is segmented into multiple independent control units, each capable of autonomously controlling one or more storage units. These control units are distributed throughout the system rather than centralized, allowing the system to maintain functionality even if some control units fail. Each control unit can independently make control decisions, providing redundancy and fault tolerance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The control architecture transitions from a one-dimensional series connection to a multi-dimensional mesh network topology. In this mesh structure, control units are interconnected through multiple pathways, allowing control signals to propagate through alternative routes if one path fails. This dimensional expansion of the control network provides inherent redundancy without significantly increasing structural complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If more control signal connections are provided at storage units, then the redundancy and fault tolerance improve, but the device complexity increases

Engineering Contradiction:
ImproveredundancyVSAvoidcontrol connection complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Each control unit is designed with universal functionality to communicate with multiple neighboring control units through standardized interfaces. The control units can serve multiple functions: receiving control commands, forwarding signals to adjacent units, and autonomously controlling storage units. This multi-functionality allows the system to achieve high redundancy without proportionally increasing complexity, as the same hardware components perform multiple roles.

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

3Reliability

If a mesh topology with multiple control signal connections is implemented, then the fault tolerance and redundancy are improved, but the control signal propagation complexity increases

Engineering Contradiction:
Improveresistance to faultsVSAvoidsignal propagation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control units operate autonomously, making independent decisions about signal forwarding based on local conditions. Each control unit monitors its own status and the status of neighboring units, automatically routing control signals through available pathways without requiring complex centralized routing algorithms. This self-service capability simplifies signal propagation in the mesh topology by distributing the decision-making process across all control units.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4305721B1Control platform architecture for grid integration of large-scale grid energy storage system
Publication Date: 2025.01.08 HITACHI ENERGY LTD
  • EP4305721B1 patent drawingFigure 1~2
  • EP4305721B1 patent drawingFigure 3~4a
  • EP4305721B1 patent drawingFigure 4b~5

AI summary

A support system (100) for an AC power transmission system, comprising an energy storage arrangement (110) comprising a plurality of storage units (112) and a main controller (120) configured to control the operation of the energy storage arrangement. Each storage unit comprises at least three control signal connections (113a, 113b, 113c) and is configured to receive a control signal from at least three storage entities via said control signal connections, wherein each of the storage entities is either the main controller or a storage unit controller of an adjacent storage unit. The storage units are arranged to forward a control signal received via a first one of said control signal connections to all adjacent storage units that are connected via the remaining ones of said control signal connections.