Vehicle Battery Pack Reconfiguration for Uncertain SOH Balancing

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Solution Overview

Problem

Electrical energy storage packs in vehicles become imbalanced due to intrinsic parametric variations and aging, leading to inefficient power distribution and potential incorrect replacements, which can result in reduced vehicle performance and unnecessary replacements.

Innovation Solution

A method and system for reconfiguring electrical energy storage packs by determining the state of health, uncertainty measures, and load sharing factors to ensure balanced energy and power distribution, using a multi-battery system dynamic model to predict power sharing and energy capabilities, and adjusting the configuration to meet vehicle performance requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If battery packs are replaced based on SOH threshold alone, then replacement decisions are simplified, but accuracy of replacement decisions deteriorates due to uncertainty in SOH estimation

Engineering Contradiction:
Improvereplacement decision processVSAvoidSOH estimation accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The system performs preliminary uncertainty analysis of SOH estimates before making replacement decisions. By calculating uncertainty measures in advance and incorporating them into the decision-making process, the system avoids hasty replacements based on inaccurate SOH estimates while maintaining a structured decision framework.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from uncertainty measurements to adjust replacement decisions. When uncertainty in SOH estimation is high, the system modifies its replacement strategy, potentially delaying replacement or performing additional diagnostics, thereby improving decision accuracy without oversimplifying the process.

Inventive Principle:
Principle #23Feedback

2Adaptability or versatility

If heterogeneous battery packs are used in the system, then flexibility in replacement is improved, but load distribution balance deteriorates due to parametric variations between packs

Engineering Contradiction:
Improvereplacement flexibilityVSAvoidload distribution balance
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The system applies local quality by assigning different roles and positions to individual battery packs based on their specific characteristics. Instead of treating all packs uniformly, the system optimizes the configuration by placing packs with similar capabilities in comparable positions and adjusting load distribution strategies for each pack according to its unique properties.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system dynamically adjusts operational parameters such as current allocation and power distribution ratios for each battery pack based on their state of health and capability. By changing these parameters in real-time, the system maintains load distribution balance despite heterogeneity in the battery packs.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If traditional SOH-based replacement strategy is used, then replacement criteria are simplified, but vehicle performance impact assessment deteriorates due to lack of uncertainty consideration

Engineering Contradiction:
Improvereplacement criteriaVSAvoidvehicle performance prediction
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The system performs preliminary uncertainty analysis and vehicle performance assessment before finalizing replacement decisions. By evaluating both the SOH estimate and its uncertainty in advance, the system predicts potential vehicle performance impacts and adjusts replacement timing to maintain reliability without significantly complicating the overall criteria.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4299370A1A method and system for reconfiguring an electrical energy storage system comprising multiple electrical energy storage packs
Publication Date: 2024.01.03 VOLVO TRUCK CORP
  • EP4299370A1 patent drawingFigure 1
  • EP4299370A1 patent drawingFigure 2A~2B
  • EP4299370A1 patent drawingFigure 2C~2D

AI summary

The invention relates to a method for reconfiguring electrical energy storage packs of an electrical energy storage system (2) of a vehicle (1), the method comprising: determining (S102) a state of health of each of the electrical energy storage packs (BP1-BP4) of the vehicle; detecting (S104) at least one malfunctioning electrical energy storage pack (BP4) of the electrical energy storage system; determining (S106) an uncertainty measure for each of the determined state of health's; concluding (S108) to replace the electrical energy storage packs (BP3) having state of health lower than a minimum state of health, and electrical energy storage packs that are concluded to be malfunctioning, evaluating (S110) the determined state of health's and the corresponding uncertainties for maintained electrical energy storage packs and a set of replacement electrical energy storage packs to find a combination of maintained electrical energy storage packs and replacement electrical energy storage packs that fulfil energy and power requirements for the vehicle taking the uncertainties in state of health into account; determining (S112) a new configuration of the electrical energy storage system including the combination of maintained electrical energy storage packs and replacement electrical energy storage packs, providing (S114) a signal indicating an arrangement of the electrical energy storage packs according to the new configuration, once electrical energy storage pack replacement is performed, determining (S116) a load sharing factor (α) indicative of a load distribution between the electrical energy storage packs of the new configuration, and if the load sharing factor fulfils a predetermined condition, performing (S118) a reconfiguration of the electrical energy storage pack to more equally distribute the load across the electrical energy storage packs.