Catalytic Converter Heating Control for Battery Current Limits
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Solution Overview
Problem
The rapid activation of the catalytic converter heating system in motor vehicles leads to excessive current draw from the battery, exceeding its maximum discharge and charge thresholds, causing premature ageing and degradation.
Innovation Solution
A control unit coordinates the activation of the electric machine's generator mode before connecting the heating system to the electric network, followed by the motor mode, and disconnects the heating system before deactivating the electric machine, maintaining current within safe thresholds.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the heating system is activated immediately to rapidly heat the catalytic converter, then the heating speed is improved, but the battery current exceeds maximum discharge and charge thresholds causing premature ageing
Solution Approach 1:
The control unit activates the electric machine in generator mode before connecting the heating system to the electric network. This preliminary action ensures that the electric machine is ready to supply power when the heating system is activated, preventing excessive current draw from the battery and avoiding current values exceeding maximum thresholds.
Solution Approach 2:
The system dynamically adjusts the activation sequence of components based on real-time conditions. The control unit monitors the state of charge of the battery and the operating modes of the electric machine, adapting the timing of heating system activation and electric machine mode switching to optimize both heating performance and battery protection.
2Productivity
If the battery supplies high current to the heating system during activation, then the heating system starts quickly, but the battery operates beyond maximum discharge threshold causing degradation
Solution Approach 1:
The electric machine acts as an intermediary between the battery and the heating system. By activating the electric machine in generator mode before heating system activation, it provides an additional power source that shares the current load, preventing the battery from exceeding its maximum discharge threshold while still enabling rapid heating system startup.
3Reliability
If the heating system is disconnected immediately after activation to protect the battery, then the battery current threshold is maintained, but the catalytic converter heating effectiveness is reduced
Solution Approach 1:
The control unit activates the electric machine in generator mode before connecting the heating system, ensuring power availability extends the heating duration. Additionally, the control unit delays disconnecting the heating system until after the electric machine is switched to motor mode, allowing the heating system to remain connected longer without risking battery overcurrent, thus maintaining both battery protection and heating effectiveness.
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 prevents excessive current draw, preserving the battery's state of charge and reducing premature ageing by ensuring the current remains within defined limits.
Implementation Method 1
an electric machine (40) able to operate in a 'generator' mode, in which the electric machine supplies electric energy to the electric network
Implementation Method 2
in a motor mode, in which the electric machine generates mechanical energy from the electric energy supplied by the electric network
Implementation Method 3
a catalytic converter (20) able to depollute the exhaust gases emitted by the combustion engine and comprising an electric heating system
Data Source
AI summary
A control unit for a hybrid motor vehicle with a combustion engine, the motor vehicle including: an electric network; a catalytic converter including an electric heating system connected to the electric network; a battery electrically connected to the electric network; an electric machine electrically connected to the electric network. The electronic control unit being configured for: activating the generator mode of the electric machine; electrically connecting the heating system to the electric power supply network at a first time, defined after a first predetermined delay with respect to the activation time of the generator mode; and activating the motor mode of the electric machine, at a second time, defined after the first time; disconnecting the heating system from the electric network at a “disconnection” time, defined after the second time.