Fuel Cell System Charge Margin Control for Regeneration

Solution Overview

Problem

In fuel cell systems, during regeneration, excessive electrical energy consumption leads to degraded fuel economy, unwanted noise, and overheating of auxiliary devices like air pumps, due to insufficient power management and margin settings.

Innovation Solution

A fuel cell system with a control unit that dynamically adjusts charge margins based on operational states, reducing power consumption and preventing overcharging by allocating electrical energy efficiently between the battery, motor, and auxiliary devices, such as the air pump.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the air pump rotation speed is increased to consume redundant electrical energy during regeneration, then the battery overcharging problem is solved, but fuel economy is degraded and the air pump overheats

Engineering Contradiction:

Improvebattery overcharging protectionVSAvoidfuel economy

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent applies dynamics by making the charge margin a variable parameter that changes based on the operational state. Specifically, the charge margin is set to a first value during steady-state operation and a second value (smaller than the first) during transient operation. This dynamic adjustment allows the system to optimize power consumption control efficiency during regeneration while preventing battery overcharging, thereby resolving the contradiction between battery protection and fuel economy.

Inventive Principle:

Principle #15Dynamics

2Reliability

If the air pump rotation speed is increased to consume redundant electrical energy during regeneration, then the battery overcharging problem is solved, but unwanted noises are generated

Engineering Contradiction:

Improvebattery overcharging protectionVSAvoidunwanted noises

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies dynamics by making the charge margin a variable parameter that changes based on the operational state. Specifically, the charge margin is set to a first value during steady-state operation and a second value (smaller than the first) during transient operation. This dynamic adjustment allows the system to optimize power consumption control efficiency during regeneration while preventing battery overcharging, thereby resolving the contradiction between battery protection and fuel economy.

Inventive Principle:

Principle #15Dynamics

3Reliability

If a fixed charge margin is set for the battery, then the battery is protected from overcharging, but excessive electrical energy is consumed by the air pump during power consumption control

Engineering Contradiction:

Improvebattery protectionVSAvoidelectrical energy consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent applies dynamics by making the charge margin a variable parameter that changes based on the operational state. Specifically, the charge margin is set to a first value during steady-state operation and a second value (smaller than the first) during transient operation. This dynamic adjustment allows the system to optimize power consumption control efficiency during regeneration while preventing battery overcharging, thereby resolving the contradiction between battery protection and fuel economy.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent applies parameter changes by modifying the charge margin parameter based on operational conditions. The charge margin is changed from a first value to a second value (smaller than the first) when transitioning to power consumption control mode. This parameter change enables more efficient utilization of electrical energy during regeneration by reducing the margin through which power is consumed, thereby resolving the contradiction between battery protection and electrical energy consumption.

Inventive Principle:

Principle #35Parameter changes

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 protects the battery from overcharging, reduces electrical energy consumption in auxiliary devices, and enhances overall system efficiency and stability during regeneration, thereby improving fuel cell vehicle performance.

Implementation Method 1

a fuel cell 12 that generates electrical energy

Methodology Applied

Scientific EffectElectrochemical reaction: Fuel Cell

Implementation Method 2

an electric motor 26 that is rotatably driven when electrical energy is supplied to the electric motor

Methodology Applied

Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 3

configured to regenerate electrical energy as a consequence of rotation

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS11091058B2Fuel cell system

Publication Date: 2021.08.17 HONDA MOTOR CO LTD

AI summary

A fuel cell system includes a FC, a TRC, an oxygen-containing gas supply apparatus, a battery, and an ECU. The ECU is capable of performing power consumption control which allows the oxygen-containing gas supply apparatus to consume electrical energy during regeneration of the TRC. The ECU is configured to determine a charge margin with respect to a charge limitation value of the battery, in a manner that the charge margin set after the power consumption control starts becomes smaller than the charge margin set before the power consumption control is performed.