Vehicle Electrical System with Coupling Unit for Voltage Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current vehicle electrical systems face inefficiencies in managing multiple voltage levels, particularly in hybrid and electric vehicles, where high-power consumers require higher voltages while low-voltage loads need 12V or 14V, often necessitating separate starters and batteries, leading to increased weight, volume, and complexity.
Innovation Solution
A vehicle electrical system with a low-voltage sub-network and a high-voltage sub-network connected via a coupling unit, utilizing battery units with individual voltage taps and reverse and forward blocking switches to selectively supply energy unidirectionally from the high-voltage to the low-voltage sub-network, eliminating the need for separate starters and lead-acid batteries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate starters and lead-acid batteries are used for low-voltage loads, then the low-voltage sub-network can be reliably supplied, but the system weight and volume increase
Solution Approach 1:
The patent merges the starter motor and alternator into a single starter-generator unit that can both start the engine and charge the battery. This consolidation eliminates separate components while maintaining the required functions, directly reducing system weight and volume while preserving reliability
Solution Approach 2:
The high-voltage battery serves multiple functions: it powers high-voltage consumers, supports the low-voltage network during transitions, and enables both electric and hybrid driving modes. This multi-functionality eliminates the need for dedicated lead-acid batteries, reducing overall system weight
2Reliability
If separate starters and lead-acid batteries are used for low-voltage loads, then the low-voltage sub-network can be reliably supplied, but the system volume increases
Solution Approach 1:
The patent merges the starter motor and alternator into a single starter-generator unit that can both start the engine and charge the battery. This consolidation eliminates separate components while maintaining the required functions, directly reducing system weight and volume while preserving reliability
Solution Approach 2:
The high-voltage battery serves multiple functions: it powers high-voltage consumers, supports the low-voltage network during transitions, and enables both electric and hybrid driving modes. This multi-functionality eliminates the need for dedicated lead-acid batteries, reducing overall system volume
3Use of energy by moving object
If battery units with individual voltage taps are used, then energy storage capacity and energy recovery are enhanced, but the device complexity increases
Solution Approach 1:
The battery is divided into multiple battery units with individual voltage taps, allowing selective connection to the low-voltage network. This segmentation enables flexible energy management and optimized energy recovery during braking by connecting only the necessary battery units, enhancing energy storage capacity while managing complexity through modular design
Solution Approach 2:
The coupling unit dynamically switches between different battery units based on energy requirements and recovery conditions. This dynamic switching optimizes energy utilization during braking and driving phases, enhancing energy storage capacity while the control system manages the complexity of the switching mechanism
4Use of energy by moving object
If the high-voltage sub-network supplies the low-voltage sub-network unidirectionally, then energy recovery during braking is improved, but the system complexity increases due to coupling unit requirements
Solution Approach 1:
The coupling unit acts as an intermediary between the high-voltage and low-voltage sub-networks, enabling unidirectional energy transfer from high-voltage to low-voltage networks. This mediator component facilitates improved energy recovery during braking by allowing the high-voltage battery to supply the low-voltage network without requiring complex bidirectional control, thus improving energy recovery while managing 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
This configuration reduces system weight and volume, enhances energy storage capacity, and improves energy recovery during braking, supporting start-stop systems and electric driving, while maintaining comfort by minimizing voltage dips during switchover.
Implementation Method 1
a coupling unit which is set up to take energy from the high-voltage sub-grid and supply it to the low-voltage sub-grid
Data Source
Figure 1~2
Figure 3~4
Figure 5
AI summary
The invention relates to a vehicle electrical system (1) for a motor vehicle, wherein the vehicle electrical system comprises: a low-voltage sub-system (21) for at least one low-voltage load (29); a high-voltage sub-system (20) for at least one high-voltage load (25); and a starter/generator (30); wherein the high-voltage sub-system (20) is connected to the low-voltage sub-system (21) by means of a coupling unit (33), which is designed to draw energy from the high-voltage sub-system (20) and to feed said energy to the low-voltage sub-system (21), wherein the high-voltage sub-system (20) has a battery (40), which is designed to produce the high voltage and to output the high voltage to the high-voltage sub-system (20) and which has at least two battery units (41) having individual voltage taps (42), which are led to the coupling unit (33). The coupling unit (33) is designed to selectively connect the battery units (41) to the low-voltage sub-system (21). The invention further relates to a motor vehicle, comprising an internal combustion engine and such a vehicle electrical system.