Hybrid Vehicle DC/DC Converter Alternator Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hybrid vehicles experience reduced energy efficiency due to the low efficiency of alternators at low output current levels, which is exacerbated when the automotive electrical component consumes high power, leading to inefficient charging of the low-voltage battery.
Innovation Solution
An electronic control unit is implemented to manage the DC/DC converter and alternator, switching between supplying power solely from the DC/DC converter when the low-voltage battery is undercharged and combining power from both the DC/DC converter and alternator when the battery's voltage or storage ratio falls below a threshold, while ensuring the alternator operates at an efficient driving point.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the alternator supplies electric power to the second electric power line when the automotive electrical component consumes a large amount of electric power, then the low-voltage battery can be sufficiently charged, but the energy efficiency is reduced due to low output current level operation
Solution Approach 1:
The control unit dynamically adjusts the output current parameter of the alternator based on the charging state of the low-voltage battery and the power consumption of automotive electrical components. By changing the operating parameters (current level) of the alternator, the system ensures efficient operation while maintaining adequate charging capability.
2Loss of energy
If the DC/DC converter supplies all electric power to the second electric power line, then the alternator can operate at high efficiency, but the low-voltage battery cannot be sufficiently charged when power consumption is high
Solution Approach 1:
The system dynamically switches between different power supply modes (DC/DC converter only, alternator only, or combined) based on real-time conditions such as battery charge level and electrical load demand. This dynamic adaptation allows the system to optimize energy efficiency while ensuring adequate charging capability under varying operating conditions.
3Power
If the alternator operates at low output current level to supply power during high consumption periods, then the power demand can be met, but the energy efficiency is reduced
Solution Approach 1:
The system merges the power supply capabilities of two sources: the DC/DC converter (which provides efficient power conversion) and the alternator (which provides additional power when needed). By combining these two power supply paths, the system can meet high power demands while maintaining overall energy efficiency, as each component operates in its optimal range.
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 enhances energy efficiency by optimizing power supply to the low-voltage battery during high power consumption by the automotive electrical instrument, ensuring efficient charging and reducing the likelihood of low-current alternator operation.
Implementation Method 1
a DC/DC converter transforming electric power of the first electric power line and supplying the transformed electric power of the first electric power line to the second electric power line
Implementation Method 2
an alternator supplying electric power generated by driving by the engine to the second electric power line
Data Source
AI summary
A DC/DC converter is driven when an inter-terminal voltage of a low-voltage battery is lower than a determination voltage and an engine is started when the inter-terminal voltage becomes lower than a determination voltage during the driving of the DC/DC converter so that an alternator is driven at a predetermined driving point at which the alternator can he efficiently driven and the DC/DC converter is controlled such that the inter-terminal voltage of the low-voltage battery becomes a rated voltage. Energy efficiency can be improved since the alternator is efficiently driven.