Fuel Cell Hydrogen Injector Current Control

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Solution Overview

Problem

In fuel cell vehicles, the hydrogen injector can accidentally close due to temporary decreases in supply current during startup of high-power auxiliaries, leading to potential fuel flow disruptions, especially when the output voltage of the auxiliary battery decreases.

Innovation Solution

An injector controller dynamically adjusts the target current value for the hydrogen injector, increasing it when high-power auxiliaries start and compensating with a secondary power supply when the voltage converter has reserve capacity, ensuring the injector remains open without excessive power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the target current value is increased to prevent accidental closure of the hydrogen injector during auxiliary startup, then the reliability of the hydrogen injector is improved, but the electric power consumption increases

Engineering Contradiction:
Improvehydrogen injector reliabilityVSAvoidelectric power consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The controller increases the target current value in advance when detecting a startup signal from a prescribed auxiliary device, before the auxiliary actually starts consuming high power. This preliminary action ensures the hydrogen injector receives sufficient current to remain open even when voltage drops occur during auxiliary startup, thereby preventing accidental closure without continuously maintaining high current

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The target current value is dynamically adjusted based on the operational state of auxiliary devices. The controller monitors startup signals and temporarily increases the target current value only during periods when auxiliaries are starting, then returns it to the normal target current value afterward. This dynamic adjustment ensures reliability during critical moments while minimizing unnecessary power consumption during normal operation

Inventive Principle:
Principle #15Dynamics

2Use of energy by moving object

If feedback control is used to maintain target current value, then the electric power consumption is reduced, but the response delay causes the hydrogen injector to close accidentally during voltage fluctuations

Engineering Contradiction:
Improveelectric power consumptionVSAvoidhydrogen injector reliability
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

Instead of relying solely on feedback control that reacts after voltage drops, the system performs preliminary action by detecting auxiliary startup signals in advance and proactively increasing the target current value before the voltage fluctuation occurs. This anticipatory approach eliminates the response delay inherent in feedback control while maintaining energy efficiency

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system combines feedback control with feedforward action. The controller monitors startup signals from auxiliary devices and uses this information to adjust the target current value proactively. This hybrid approach maintains the energy efficiency of feedback control while adding the predictive capability needed to prevent accidental closure during rapid voltage changes

Inventive Principle:
Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution prevents accidental closure of the hydrogen injector during startup, maintaining stable fuel flow and reducing excess power consumption by effectively managing voltage fluctuations and reserve power utilization.

Implementation Method 1

A typical hydrogen injector is an electromagnetically-driven on-off valve, and is of a normally closed type. The normally closed-type valve remains closed when the valve is not supplied with current, and opens when the valve is supplied with a current exceeding a predetermined current threshold.

Methodology Applied
Scientific EffectElectromagnetic actuation: Electromagnet

Implementation Method 2

a voltage converter configured to step down the output voltage of the second power supply and supply electric power to the first power supply

Methodology Applied
Scientific EffectElectrical energy conversion:

Data Source

PatentEP3473481B1Fuel cell vehicle
Publication Date: 2022.11.09 TOYOTA JIDOSHA KK
  • EP3473481B1 patent drawingFigure 1
  • EP3473481B1 patent drawingFigure 2
  • EP3473481B1 patent drawingFigure 3

AI summary

A fuel cell vehicle includes a hydrogen injector (12), a controller (13), and a first power supply (20). The hydrogen injector (12) is configured to open when supplied with a current large than or equal to a predetermined current threshold (Ith). The controller (13) is configured to control a current that is supplied to the hydrogen injector (12) such that the supply current follows a target current value. The first power supply (20) is configured to supply electric power to the hydrogen injector (12) and a prescribed auxiliary. The controller (13) is configured to increase the target current value when the controller (13) detects at least one of a first start signal for starting the prescribed auxiliary and a second start signal for informing startup of the prescribed auxiliary.