Active Current-Limiting Device for Vehicle Energy Storage Charging
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing charging systems for electrical energy storage devices in vehicles, such as airbag systems, face inefficiencies due to high initial supply currents that cause mass displacements, thermal and mechanical stress, and increased component wear, leading to reduced device efficiency and higher assembly costs.
Innovation Solution
An active current-limiting device is integrated into the main current path to dynamically regulate the supply current, ensuring it does not exceed a predefined maximum, thereby minimizing power loss and eliminating the need for additional resistors, which enhances the efficiency of the voltage transformer and reduces component count.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If resistors are added to the main current path to limit maximum supply current, then current limiting is achieved, but efficiency is reduced due to power dissipation in resistors
Solution Approach 1:
The patent uses an active current-limiting device that dynamically changes its internal resistance parameter based on operating conditions. The device presents high resistance during initial charging to limit current, then transitions to low resistance during normal operation, eliminating continuous power dissipation. This dynamic parameter change resolves the contradiction between current limiting and efficiency.
2Reliability
If multiple resistors and capacitors are added to filter interference signals and limit current, then circuit protection is improved, but device complexity increases
Solution Approach 1:
The active current-limiting device performs multiple functions simultaneously: it limits inrush current, filters interference signals, and protects the voltage transformer device. By consolidating these protection functions into a single intelligent component rather than using multiple passive components, the patent reduces device complexity while maintaining or improving reliability.
Solution Approach 2:
The patent replaces the mechanical/passive approach of using multiple discrete resistors and capacitors for current limiting and filtering with an active electronic control system. This substitution allows for more efficient current management and reduces the number of physical components needed, thereby reducing device complexity.
3Productivity
If high supply current flows during switch-on, then charging speed is improved, but thermal and mechanical loads increase reducing component life
Solution Approach 1:
The active current-limiting device implements periodic or staged current control during the charging process. It allows high current only during brief initial phases when necessary, then reduces current to sustainable levels. This periodic action pattern maintains charging productivity while preventing excessive thermal and mechanical loads that would reduce component lifespan.
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 achieves high charging efficiency by minimizing power loss and reducing component count, leading to lower thermal stress and assembly costs, while ensuring the energy storage device is charged effectively without exceeding maximum current limits.
Implementation Method 1
A switched voltage transformer device (20), which raises a first electrical potential (VE) of an energy storage device (CE) above an electrical supply potential (VB) of an electrical power source (E), is situated downstream from the active current-limiting device in the main current path
Data Source
AI summary
A device is described for charging an electrical energy storage device, which has an active current-limiting device in a main current path in order to limit a supply current to a predefined maximum current. A voltage transformer device is situated downstream from the current-limiting device for raising the potential of the electrical energy storage device over a supply potential.