Galvanically Coupled DC-DC Converter for Multi-Voltage Vehicle Branches
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Solution Overview
Problem
Existing vehicle electrical systems with different nominal voltages require separate rechargeable batteries for each branch, which is inefficient and costly.
Innovation Solution
A galvanically coupling DC-to-DC converter with three transistors connected in series, allowing for symmetrical load inductor distribution around the middle transistor, enabling voltage shifting and coupling between branches with different nominal voltages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate rechargeable batteries are used for each voltage branch, then each branch has independent power supply, but system complexity and cost increase
Solution Approach 1:
The patent merges multiple battery systems into a single battery system by using a DC-to-DC converter to provide galvanic isolation and voltage conversion. This allows one battery to serve multiple voltage branches (e.g., 400V and 800V) through controlled power conversion, eliminating the need for separate batteries while maintaining independent power supply capability for each branch.
Solution Approach 2:
The DC-to-DC converter acts as an intermediary between the single battery and multiple voltage branches. It provides galvanic isolation and performs voltage conversion to match different nominal voltages of various branches, enabling one battery to reliably power multiple branches with different voltage requirements without direct electrical connection to each.
2Device complexity
If conventional half-bridge topology with two switches is used, then circuit structure is simple, but symmetrical voltage shifting capability is limited
Solution Approach 1:
The patent segments the switching function into three transistors arranged in a series circuit, with load inductors distributed symmetrically around the middle transistor. This segmentation creates two connecting points that enable symmetrical voltage shifting capability while maintaining a relatively simple circuit structure compared to more complex multi-active-bridge topologies.
Solution Approach 2:
The patent applies local quality by placing load inductors at specific locations (connecting points) in the circuit rather than uniformly distributing them. The symmetrical arrangement of inductors around the middle transistor creates local symmetry that enables the overall system to achieve symmetrical voltage shifting capability between positive and negative voltage levels.
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
The DC-to-DC converter efficiently couples branches with different nominal voltages, eliminating the need for separate batteries and simplifying the electrical system while maintaining effective voltage conversion.
Implementation Method 1
The DC-to-DC converter has a first, a second and a third transistor as converter switching elements which are connected to one another in a series circuit
Implementation Method 2
A respective load inductor is connected to the two connecting points. The load inductors are each connected in series to the connecting points
Data Source
AI summary
A galvanically coupling DC-to-DC converter has a first side and a second side. The first side has a first potential and a second potential. The DC-to-DC converter has a first, a second and a third transistor. The transistors are connected in a series circuit via a first and a second connecting point and are connected between the potentials of the first side. A respective load inductor is connected to the two connecting points. The load inductors are each connected between one of the connecting points and one of two potentials of the second side of the DC-to-DC converter.