Hybrid Vehicle Power Control for Battery Charge and Catalyst Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In hybrid vehicles, catalyst deterioration occurs when the catalyst temperature exceeds a predetermined threshold due to fuel cutoff, which is necessary for battery protection but harmful to the catalyst, especially in lean atmospheres.
Innovation Solution
A control method that manages electric power exchange between the drive motor and battery, charges the battery using a generator, and treats exhaust gas with a catalyst, adjusting input power based on battery state of charge and catalyst temperature to prevent fuel supply cutoff when necessary, and maintains engine output to reduce catalyst exposure to lean conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fuel supply to the engine is stopped to protect the battery when state of charge reaches near upper limit value, then battery protection is improved, but catalyst deterioration occurs due to exposure to lean atmosphere at high temperature
Solution Approach 1:
The control method changes the operating parameters of the engine based on catalyst temperature. When catalyst temperature exceeds the predetermined threshold, the engine output is maintained by continuing fuel supply despite battery charge level, rather than stopping fuel supply. This parameter change (maintaining fuel supply condition) prevents catalyst deterioration while still managing battery charge through alternative means.
Solution Approach 2:
The control system continuously monitors catalyst temperature and uses this feedback to determine fuel supply strategy. When catalyst temperature is detected to exceed the threshold, the system feedback-adjusts the fuel supply decision to maintain engine output, preventing the harmful lean atmosphere condition that would otherwise occur during battery protection mode.
2Use of energy by moving object
If fuel supply is stopped to consume regenerative electric power by motoring the engine, then battery charge management is improved, but catalyst temperature exceeds threshold causing deterioration
Solution Approach 1:
The control method changes the decision parameter for fuel cutoff based on catalyst temperature. Normally, fuel supply would be stopped when regenerative power exceeds available input power to battery. However, when catalyst temperature exceeds the threshold, the parameter change maintains fuel supply to prevent catalyst deterioration, even though this means accepting the power imbalance.
Solution Approach 2:
The system converts the potentially harmful condition of excess regenerative power (which would normally require fuel cutoff) into a beneficial outcome by using the catalyst temperature condition as an additional decision criterion. This prevents catalyst deterioration while still managing battery charge through the generator's generated electric power.
3Reliability
If engine output is reduced to manage battery charge, then battery protection is improved, but catalyst may be exposed to lean atmosphere causing deterioration
Solution Approach 1:
The control method changes the engine output management strategy based on catalyst temperature. When catalyst temperature exceeds the threshold, the system maintains engine output by continuing fuel supply rather than reducing output for battery protection, thus preventing catalyst deterioration while managing battery charge through the generator.
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 method effectively suppresses catalyst deterioration by controlling engine output and power supply to maintain catalyst temperature below the threshold, ensuring efficient operation and catalyst longevity.
Implementation Method 1
treating exhaust gas discharged from the engine by a catalyst
Implementation Method 2
charging the battery by a generator driven by an engine for power generation
Implementation Method 3
exchanging electric power between a drive motor and a battery
Data Source
AI summary
Control for a hybrid vehicle includes: reducing available electric power to the battery as a state of charge approaches a predetermined upper limit; when the state of charge nears the upper limit and the available electric power is smaller than a sum of the regenerative electric power and the generated electric power, stopping fuel to the engine; and consuming regenerative electric power by supplying electric power from the battery to the generator. Fuel supply to the engine is stopped when temperature of the catalyst is equal to or lower than a predetermined temperature when power generation is stopped, and an output of the engine is maintained by continuing the fuel supply to the engine when temperature of the catalyst exceeds the predetermined temperature. The engine output is reduced when a moving average of current exceeds a predetermined value or when negative electrode potential is lower than a predetermined potential.