EHC Insulator Temperature Estimation for Power Feed Control
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Solution Overview
Problem
Existing electrical heated catalyst systems face issues with insulating performance when the temperature of the catalyst is high, leading to reduced electrical resistance and potential damage, as existing technologies do not provide adequate protective control measures.
Innovation Solution
A vehicle system that includes a power storage device, a catalytic device with an insulator and a control device that determines power feed to the catalytic device based on the temperature of the insulator and catalyst base material, ensuring insulating performance by setting threshold temperatures and estimating temperatures before and after the vehicle's operational state changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If electric power is fed to heat the catalytic device at high voltage, then heating efficiency is improved, but insulating performance deteriorates due to temperature-induced resistance reduction
Solution Approach 1:
The control device estimates the insulator temperature in advance before power feed occurs and determines whether power feed is allowed based on this preliminary temperature assessment. This prevents the insulator from reaching temperatures that would compromise its insulating performance while still enabling efficient heating when conditions are appropriate.
Solution Approach 2:
The control device continuously monitors temperature conditions and uses this feedback to dynamically control power feed to the catalytic device. By estimating insulator temperature based on catalyst temperature and thermal properties, the system adjusts power feed decisions to maintain insulating performance while achieving heating efficiency.
2Productivity
If power feed is allowed continuously to maintain catalyst temperature, then purification efficiency is improved, but insulator damage risk increases
Solution Approach 1:
Before each power feed operation, the control device performs a preliminary estimation of the insulator temperature. This advance assessment allows the system to determine whether power feed would cause the insulator to exceed safe temperature thresholds, thereby preventing insulator damage while enabling purification when conditions permit.
Solution Approach 2:
The control device dynamically adjusts power feed decisions based on real-time temperature conditions. By continuously estimating insulator temperature and comparing it against threshold values, the system adaptively controls heating operations to maintain purification efficiency while avoiding insulator damage under varying operating conditions.
3Reliability
If temperature monitoring is performed continuously to ensure insulator safety, then reliability is improved, but system complexity increases
Solution Approach 1:
Instead of directly monitoring insulator temperature with dedicated sensors, the control device uses the catalyst temperature as an intermediary parameter to estimate insulator temperature. This approach leverages the thermal relationship between catalyst and insulator, providing reliable insulator temperature assessment without requiring additional complex monitoring hardware.
Solution Approach 2:
The control device uses existing temperature data from the catalyst monitoring system to simultaneously assess both catalyst performance and insulator safety conditions. This self-service approach allows the system to perform dual functions with existing resources, improving reliability without increasing system complexity.
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
The system allows for safe and efficient power feeding to the electrical heated catalyst while maintaining insulating performance and protecting the catalyst base material, ensuring effective exhaust purification.
Implementation Method 1
an insulator provided between the catalytic device and a housing accommodating the catalytic device
Implementation Method 2
a catalytic device configured to be able to electrically heat with electric power from the power storage device
Data Source
AI summary
In a vehicle including an EHC containing a catalyst base material and an insulator insulating the EHC from the outside, an ECU estimates a temperature of the catalyst base material and a temperature of the insulator immediately after a state of the vehicle is switched from a Ready-OFF state to a Ready-ON state, as a base material temperature for determination THcpost and an insulator temperature for determination THipost, respectively. Then, when base material temperature for determination THcpost is lower than a base material threshold temperature THcth and when insulator temperature for determination THipost is lower than an insulator threshold temperature THith, the ECU allows EHC power feed, and otherwise it does not allow but prohibits EHC power feed.