Dual-Voltage Vehicle Power Supply With Capacitor Load Buffering
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing in-vehicle power supply systems face challenges in reducing the cost and diameter of power supply lines while minimizing electric power loss, particularly when handling both high and low voltage requirements for various electrical components, leading to inefficiencies and increased costs.
Innovation Solution
The proposed in-vehicle power supply system employs a dual-voltage architecture with a main battery for 12V and a power control unit that converts high-voltage DC power to 48V, utilizing a capacitor to manage power supply to large electric loads and reducing current flow, thereby minimizing wire diameter and power loss, and includes a control unit to manage charging and discharging of the capacitor for efficient power distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a 12V power supply system is used for large electric power loads, then the system can supply power to both small and large loads, but the current becomes very large causing large electric power loss and requiring thick power supply lines
Solution Approach 1:
The patent changes the voltage parameter from 12V to 48V for supplying large electric power loads. By increasing the voltage while maintaining the same power level, the current is reduced proportionally (P=IV), thereby reducing electric power loss (P=I²R) and allowing the use of thinner power supply lines with smaller cross-sectional areas.
2Loss of energy
If a 48V power supply system is used for large electric power loads, then the current and electric power loss are reduced, but the cost of the power supply system increases significantly
Solution Approach 1:
The patent segments the power supply system into two distinct systems: a 12V system for small electric power loads and a 48V system for large electric power loads. This segmentation allows each subsystem to be optimized for its specific voltage level, reducing the need for expensive high-voltage components throughout the entire system and lowering overall system cost while maintaining energy efficiency for large loads.
3Quantity of substance
If a 48V power supply system is used for large electric power loads, then the current is reduced, but voltage fluctuation occurs causing unstable operation of in-vehicle devices
Solution Approach 1:
The patent introduces a DC/DC converter as an intermediary device between the 48V power supply system and the 12V loads. This converter stabilizes the voltage output from the 48V system, converting and regulating it to a stable 12V level for devices that require lower voltage, thereby eliminating voltage fluctuation issues and ensuring reliable operation of in-vehicle devices while maintaining the benefits of reduced current in the high-voltage system.
4Loss of energy
If thick electric wires are used for power supply lines to handle large current, then electric power loss is reduced, but the diameter of the power supply line increases and cost increases
Solution Approach 1:
The patent changes the operating voltage parameter to 48V for large power loads, which reduces the current by a factor of 4 compared to 12V operation. Since electric power loss is proportional to the square of the current (P=I²R), this voltage increase dramatically reduces power loss, allowing the use of power supply lines with smaller cross-sectional areas and smaller diameters, thereby reducing material costs and installation 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 solution effectively reduces the diameter of power supply lines, minimizes electric power loss, and prevents voltage fluctuations, thereby lowering the overall vehicle cost and ensuring stable operation of electrical components.
Implementation Method 1
a capacitor configured to accumulate electric charge from the first power supply line and discharge the accumulated electric charge to the large electric power load
Implementation Method 2
a step-down conversion unit configured to step down a voltage of the first power supply line and supply the power of the power supply to the second power supply line
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An in-vehicle power supply system includes: a main battery; an upper power supply unit configured to supply power of a power supply to the main battery; a first power supply line allocated to conduct the power of the power supply of a first voltage; a second power supply line allocated to conduct the power of the power supply of a second voltage lower than the first voltage; a step-down conversion unit configured to step down a voltage of the first power supply line to supply the power of the power supply to the second power supply line; and a capacitor. The upper power supply unit, the capacitor, and an input of the step-down conversion unit are connected to the first power supply line. The main battery and an output of the step-down conversion unit are connected to the second power supply line.