Hydrogen Refueling Controller Using Pre-Estimated State of Charge Correction

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Solution Overview

Problem

Existing hydrogen vehicle refueling methods are inefficient and deviate from conventional fuel refueling methods, often resulting in incomplete filling and longer refueling times, particularly due to reliance on pressure and temperature measurements that can be misleading and require lengthy processes to ensure accurate state of charge.

Innovation Solution

A method that uses a pre-estimated correction of state of charge to determine the upper state of charge for terminating refueling, allowing for faster and more efficient hydrogen refueling by continuing to fill until an estimated state of charge above 100% is reached, then closing the valve before settling, thereby ensuring a higher final state of charge without waiting for pressure and temperature to stabilize.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If refueling is terminated when estimated state of charge reaches 100% tank rated density, then refueling safety is ensured, but refueling time is extended and final state of charge is incomplete

Engineering Contradiction:
Improverefueling safetyVSAvoidrefueling time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-estimating the correction of state of charge that occurs after valve closing. The controller calculates an upper state of charge target that accounts for the expected decrease in estimated state of charge after refueling terminates, allowing the refueling process to continue long enough to achieve complete filling without excessive waiting time.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses feedback by continuously monitoring temperature and pressure during refueling to calculate the estimated state of charge in real-time. The controller adjusts the refueling termination criterion based on the measured values, dynamically determining when to close the valve to achieve both safety and efficiency.

Inventive Principle:
Principle #23Feedback

2Measurement precision

If refueling waits for pressure and temperature to stabilize, then measurement accuracy is improved, but refueling time is significantly extended

Engineering Contradiction:
Improvestate of charge measurement accuracyVSAvoidrefueling time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-calculating the expected stabilization behavior of pressure and temperature. The controller uses this prediction to determine an optimal termination point before full stabilization occurs, avoiding the need to wait for complete stabilization while still achieving sufficient measurement accuracy for safe refueling completion.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies dynamics by adapting the refueling termination criterion based on real-time measurements of temperature and pressure. The system dynamically adjusts the estimated state of charge calculation and termination timing to balance measurement accuracy with refueling efficiency, rather than using a fixed stabilization wait time.

Inventive Principle:
Principle #15Dynamics

3Reliability

If conventional refueling methods are used for hydrogen, then safety standards are met, but the process is inefficient and deviates from user expectations

Engineering Contradiction:
Improvesafety standard complianceVSAvoidrefueling efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent applies parameter changes by modifying the refueling termination criterion from a fixed 100% tank rated density target to a dynamic upper state of charge target that accounts for post-refueling stabilization. This parameter adjustment allows the system to maintain safety compliance while significantly improving refueling efficiency and predictability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the traditional mechanical approach of waiting for physical stabilization with a computational approach using pre-estimated correction factors. This substitution allows the system to determine refueling completion based on calculated predictions rather than passive waiting, improving efficiency while maintaining safety.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 approach allows for a faster and more predictable refueling process that achieves a state of charge closer to 100% within the SAE J2601 standard, reducing refueling time and ensuring a higher amount of hydrogen in the tank, even when pressure and temperature measurements are uncertain or fluctuating.

Implementation Method 1

monitoring the temperature and pressure of the hydrogen gas in vehicle tank

Methodology Applied
Scientific EffectTemperature measurement:

Implementation Method 2

monitoring the temperature and pressure of the hydrogen gas in vehicle tank

Methodology Applied
Scientific EffectPressure measurement:

Implementation Method 3

the flow of hydrogen gas in the hose being controlled by a controller controlling a valve

Methodology Applied
Scientific EffectPressure-driven flow: Pressure Gradient

Data Source

PatentEP3631282B1Method of refueling a hydrogen vehicle
Publication Date: 2021.07.07 NEL HYDROGEN AS
  • EP3631282B1 patent drawingFigure 1~2
  • EP3631282B1 patent drawingFigure 3
  • EP3631282B1 patent drawingFigure 4A

AI summary

The invention relates to a method of refueling a tank of a vehicle with a hydrogen gas from a hydrogen refueling station, the refueling includes initiating flow of hydrogen gas in a hose being controlled by a controller controlling a valve, opening the valve and monitoring the temperature and pressure of the hydrogen gas in tank, based on the monitored temperature and the monitored pressure establishing an estimated state of charge during the refueling, terminating the refueling when the estimated state of charge reaches an upper state of charge being above the tank rated density, the upper state of charge being determined on the basis of a pre-estimated correction of state of charge, the pre-estimated correction of state of charge designating a decrease of the estimated state of charge in the vehicle tank after the closing of the valve disconnecting the hose between the vehicle tank and the hydrogen source.