Vehicle Battery Pack Uncertainty Control for Available Power

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Solution Overview

Problem

Existing energy storage systems in vehicles, particularly those with multiple battery packs connected in parallel, face challenges in accurately estimating State-of-Power (SoP) and State-of-Energy (SoE), leading to conservative power utilization and potential issues like power loss, thermal problems, and safety hazards due to aggressive estimates.

Innovation Solution

A method that acquires battery pack performance data, including SoP and SoE with associated uncertainties, and processes this data using an estimation model to determine the maximum expected uncertainty of the overall energy storage system, allowing for proactive management of charging/discharging loads and operational windows, thereby improving system availability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conservative SoP estimation is used to ensure safety, then system reliability is improved, but power utilization is reduced

Engineering Contradiction:
Improvesystem reliabilityVSAvoidpower utilization
Core Design Contradiction:
ReliabilityVSPower

Solution Approach 1:

The system continuously monitors individual battery pack SoP estimates and their uncertainties, feeding this information back to the central controller which adjusts the overall system power limits dynamically. This feedback mechanism allows the system to maintain safety while optimizing power utilization based on real-time conditions of each battery pack.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system changes the parameter of power limits from fixed conservative values to dynamic values that adapt based on the sum of uncertainties from individual battery packs. By adjusting power limits according to actual uncertainty levels, the system achieves both safety and optimal power utilization.

Inventive Principle:
Principle #35Parameter changes

2Power

If aggressive SoP estimation is used to maximize power utilization, then power capability is improved, but system safety is compromised

Engineering Contradiction:
Improvepower capabilityVSAvoidthermal problems and safety hazards
Core Design Contradiction:
PowerVSObject-affected harmful factors

Solution Approach 1:

The system uses feedback from individual battery pack monitoring to continuously adjust power limits. When uncertainty in SoP estimation increases, the system automatically reduces power limits to prevent thermal problems and safety hazards, while still allowing maximum power utilization when conditions permit.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary estimation of uncertainties from individual battery packs before setting overall system power limits. This preliminary action allows the system to proactively adjust power capabilities to avoid safety issues before they occur, rather than reacting after problems arise.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If individual battery pack limitations are considered separately, then measurement precision is improved, but system availability is reduced

Engineering Contradiction:
ImproveSoP estimation precisionVSAvoidsystem availability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system merges the SoP estimates and their uncertainties from multiple individual battery packs into a unified system-level assessment. By combining information from all battery packs and considering their collective performance, the system achieves both precise measurement and high availability, avoiding the conservative limitations that result from considering each pack in isolation.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system changes from using individual battery pack power limits to using a system-level power limit based on the sum of uncertainties from all packs. This parameter change allows the system to achieve higher availability while maintaining measurement precision through the aggregated uncertainty assessment.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4257407A1A method for improving the availability of an energy storage system in a vehicle
Publication Date: 2023.10.11 VOLVO TRUCK CORP
  • EP4257407A1 patent drawingFigure 1
  • EP4257407A1 patent drawingFigure 2
  • EP4257407A1 patent drawingFigure 3

AI summary

The present invention relates to a method for improving the availability of an energy storage system in a vehicle. The energy storage system comprises a plurality of battery packs, and the method comprises: - acquiring (S10) battery pack performance data comprising at least one of the state-of-power, SoP, and the state-of-energy, SoE, for each one of the battery packs, wherein the acquired SoP and/or SoE for each battery pack comprises an estimated value (SoP1-SoPn; SoE1-SoEn) and associated uncertainty (σP1- σPn; σE1- σEn); - processing (S20) the battery pack performance data with an estimation model adapted to relate the sum of the uncertainties (σP1- σPn; σE1- σEn) to a maximum expected uncertainty (σPo, σEo) of an overall SoP and/or SoE of the energy storage system; and - setting (S30) the maximum allowed energy storage system charging/discharging load and/or energy storage system operational windows in response to the overall SoP and/or SoE of the energy storage system and corresponding maximum expected uncertainty (σPo, σEo).