Vehicle Engine-Generator Control for Low-Voltage Battery Backup
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
When a generator in a vehicle is set to a power generation amount non-control state due to an abnormal state, there is a risk of interrupted power supply to the high voltage battery, leading to a decrease in its power storage amount and potential exhaustion of auxiliary devices, limiting the vehicle's travel distance.
Innovation Solution
A control device that increases the engine's rotational speed to generate a counter electromotive force equal to or higher than the high voltage battery's voltage, supplying power from the high voltage battery to the low voltage battery via a DC/DC converter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the electric motor is set to a non-driven state when abnormality is detected, then damage to the electric motor is minimized, but the vehicle can still travel with the engine as traveling power source
Solution Approach 1:
The patent segments the traveling power source system into two independent pathways: the electric motor pathway and the engine pathway. When the electric motor detects abnormality, only that segment is isolated by setting it to a non-driven state, while the engine pathway remains fully functional, allowing the vehicle to continue traveling without complete mobility loss.
2Reliability
If power is continuously supplied from the high voltage battery to the low voltage battery via DC/DC converter when the electric motor is non-driven, then the low voltage battery functions normally, but the power storage amount of the high voltage battery gradually decreases
Solution Approach 1:
The patent applies partial action by providing power from the high voltage battery to the low voltage battery only through the DC/DC converter when absolutely necessary (when electric motor is non-driven), rather than continuous full-power transfer. This partial power transfer maintains auxiliary device functionality while minimizing the depletion of high voltage battery storage.
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 solution maintains power supply to the low voltage battery, preventing battery exhaustion and reducing the decrease in travelable distance by ensuring continuous power delivery.
Implementation Method 1
a rotational speed of the engine to increase so that a counter electromotive force generated in the generator becomes equal to or more than a voltage of the high voltage battery
Data Source
AI summary
The vehicle includes an engine, a generator coupled to the engine, a high voltage battery capable of transmitting and receiving electric power to and from the generator, a low voltage battery that supplies electric power to an auxiliary device that drives the engine, and DC/DC converters provided between the high voltage battery and the low voltage battery. The electronic control device executes an increase control for increasing the engine rotational speed, which is the rotational speed of the engine, so that the counter electromotive force generated by the generator becomes equal to or higher than the battery voltage of the high voltage battery, and supplies electric power from the high voltage battery to the low voltage battery through DC/DC converter when the generator is in the power generation amount non-control state due to the occurrence of the abnormal state.