Sodium-Sulfur Battery Level Equalization Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The management of sodium-sulfur batteries in interconnected systems combining fluctuating natural energy power generation devices with electric power storage-compensation devices becomes complex due to variations in remaining battery levels, requiring manual adjustments and increased operational burdens.

Innovation Solution

A method that continuously monitors and adjusts the remaining battery level of each sodium-sulfur battery by using a multiplying factor based on the deviation between the power generation plan and actual output, distributing charge or discharge quantities to maintain uniform levels across all batteries.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If natural energy power generation devices are used to generate clean power, then carbon dioxide emissions are suppressed and environmental benefits are achieved, but output fluctuations occur due to variable natural energy availability

Engineering Contradiction:
Improvecarbon dioxide emissionsVSAvoidoutput stability
Core Design Contradiction:
Object-affected harmful factorsVSReliability

Solution Approach 1:

The system segments the power generation portfolio into multiple independent components: natural energy power generation devices (wind, solar, geothermal) and conventional power generation devices. This segmentation allows each component to operate independently while contributing to the overall system output, enabling the natural energy portion to provide environmental benefits while the conventional portion ensures output stability during low natural energy availability

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system merges natural energy power generation devices with conventional power generation devices into a unified interconnected system. This combination allows the system to simultaneously achieve the environmental benefits of clean power generation and the output stability of conventional generation, as the total system output is the sum of both components and can maintain reliability even when natural energy availability fluctuates

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If multiple sodium-sulfur batteries are operated to maintain power generation plans, then output compensation capability is improved, but variations in remaining battery levels increase management complexity

Engineering Contradiction:
Improvepower generation plan adherenceVSAvoidmanagement complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control device implements feedback control by continuously monitoring the remaining battery level of each sodium-sulfur battery and using this information to adjust the charge/discharge control values. The control value for each battery is calculated based on its current state relative to the average battery level, creating a self-regulating system that automatically maintains uniform battery levels without requiring complex manual management

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system enables self-service operation where the control device automatically adjusts the charge/discharge operations of each battery based on real-time monitoring of battery states. The batteries self-regulate their charge/discharge cycles through the control algorithm that responds to their individual remaining levels, eliminating the need for external manual intervention and simplifying management while ensuring power generation plan adherence

Inventive Principle:
Principle #25Self-service

3Productivity

If sodium-sulfur batteries frequently repeat charge and discharge to compensate for natural energy fluctuations, then output compensation capability is improved, but maintaining uniform battery levels becomes difficult

Engineering Contradiction:
Improveoutput compensation capabilityVSAvoidbattery level uniformity
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The system dynamically changes the charge/discharge control parameters for each battery based on its current state. The control value is adjusted as a function of the difference between each battery's remaining level and the average remaining level, allowing batteries that have discharged more to receive preferential charging. This parameter adaptation enables frequent charge/discharge cycles for output compensation while automatically maintaining battery level uniformity across the system

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2330679B1Method for controlling sodium-sulfur battery
Publication Date: 2017.11.01 NGK INSULATORS LTD
  • EP2330679B1 patent drawingFigure 1
  • EP2330679B1 patent drawingFigure 2

AI summary

A remaining battery level of each individual sodium-sulfur battery constituting a plurality of sodium-sulfur batteries is managed, a remaining battery level target value common to all sodium-sulfur batteries is set, and input/output power distributed to each individual sodium-sulfur battery is controlled based on a difference between the target value and the remaining battery level of the sodium-sulfur battery. This enables a uniform remaining battery level among the sodium-sulfur batteries to be attained.