Fuel Cell Controller Deviation Detection

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Solution Overview

Problem

In fuel cell systems, it is challenging to identify which power-consuming device is causing deviations in electric power consumption, making it difficult to prevent overcharge or overdischarge of the secondary battery.

Innovation Solution

A fuel cell system with a controller that includes a calculation section, estimation section, and identification section to calculate and estimate electric power consumption of power-consuming devices, identify deviations, and adjust operation command values or power generation to minimize differences between actual and estimated charge/discharge amounts, thereby preventing overcharge or overdischarge.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the secondary battery stores dump electric power or compensates for power shortage, then energy management is optimized, but it becomes difficult to identify which power consuming device causes deviation in electric power consumption

Engineering Contradiction:
Improveenergy management efficiencyVSAvoiddifficulty to identify deviating power consuming device
Core Design Contradiction:
ProductivityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent segments the total electric power consumption into individual components by calculating consumption for each power consuming device separately using operation command values. This segmentation enables identification of which specific device causes deviation, resolving the contradiction by maintaining energy management efficiency while enabling device-level detection capability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements feedback by comparing actual electric power consumption with estimated consumption and using this difference to identify deviating devices. The controller continuously monitors and adjusts based on this feedback loop, allowing identification of problematic devices without compromising overall energy management optimization.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If the controller monitors all power consuming devices to identify consumption deviations, then device identification accuracy improves, but system complexity increases

Engineering Contradiction:
Improvedeviation detection accuracyVSAvoidcontroller complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies self-service by having each power consuming device report its operation command values to the controller, which then autonomously calculates and monitors its own power consumption contribution. This self-service approach enables accurate deviation detection without requiring additional sensors or complex monitoring infrastructure for each device.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The controller acts as an intermediary that receives operation command values from power consuming devices, calculates their power consumption, and identifies deviations. This intermediary role allows the system to maintain measurement precision while avoiding direct complex interactions between devices, thereby managing system complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If the operation command value for a power consuming device is varied to identify deviations, then device identification capability improves, but control stability deteriorates

Engineering Contradiction:
Improvedevice identification capabilityVSAvoidcontrol stability
Core Design Contradiction:
Measurement precisionVSStability of the object's composition

Solution Approach 1:

The patent implements periodic action by varying operation command values in a controlled, periodic manner rather than continuously or randomly. This periodic variation allows the system to identify deviating devices through systematic testing while maintaining overall control stability, as the variations are predictable and can be compensated for in the identification algorithm.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent applies partial action by varying operation command values only for specific devices under test rather than all devices simultaneously. This partial variation maintains control stability for the overall system while enabling identification capability for individual devices, balancing the competing requirements.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3722138B1Fuel cell system and control method
Publication Date: 2022.05.11 TOYOTA JIDOSHA KK
  • EP3722138B1 patent drawingFigure 1
  • EP3722138B1 patent drawingFigure 2
  • EP3722138B1 patent drawingFigure 3

AI summary

A fuel cell system includes a fuel cell, a plurality of power consuming devices, a secondary battery, a charge-discharge amount sensor, and a controller configured to control operations of the plurality of power consuming devices. An identification section of the controller is configured to execute a variation process of varying the operation command value of one of the plurality of power consuming devices and, in a second case where an absolute value of a difference between an amount of change in the actual amount of charge and discharge and an amount of change in the estimated amount of charge and discharge before and after execution of the variation process is greater than a second threshold, identify the power consuming device, for which the operation command value is varied, as the device to be identified.