Power Supply Path Switching Voltage Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Electric road vehicles face safety issues and inefficiencies when switching between power supply paths, particularly due to high voltage risks and component wear from electric arcs during power transitions, and existing safety systems are bulky and expensive.
Innovation Solution
A method and system for smoothly switching between power supply paths by opening the current path, controlling the terminal voltage of the electrical machine to match the second power supply path, and then closing the new path, reducing the risk of jolts and arcs, and allowing direct high-power connection without intermediate galvanic isolation when safe.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If direct switching between power supply paths is performed without voltage control, then switching speed is improved, but electric arcs and component wear increase
Solution Approach 1:
The patent applies preliminary action by controlling the terminal voltage of the first connection terminal means to substantially match the power supply voltage of the second power supply path before closing the second power supply path. This pre-synchronization of voltages prevents harmful electric arcs during switching, while the entire switching process remains brief to maintain fast switching speed.
2Reliability
If safety systems with galvanic isolation are used, then safety is improved, but device complexity and cost increase
Solution Approach 1:
The patent applies local quality by implementing galvanic isolation only at specific locations and times - specifically using an isolating transformer or DC-DC converter only when switching between power supply paths with different safety requirements. During normal operation with consistent safety levels, direct connection is maintained, reducing overall system complexity while preserving safety where needed.
3Duration of action of stationary object
If voltage control during switching is implemented, then component wear is reduced, but switching time increases
Solution Approach 1:
The patent maintains continuity of useful action by ensuring that the electrical machine continues to receive power throughout the switching process. The terminal voltage is controlled to match the incoming power supply path voltage, preventing interruptions in power delivery to the electrical machine while minimizing the duration of voltage control to reduce switching time.
Data Source
AI summary
The present invention relates to a method for switching power supply path of at least one electrical machine, said electrical machine being arranged to be selectively supplied power by a first power supply path and a second power supply path, respectively, by alternately opening and closing said power supply paths, said first and second power supply paths being arranged to connect a power supply source to a first connection terminal means of said electrical machine. The method includes, when switching from said first power supply path to said second power supply path: opening said first power supply path; by means of said electrical machine, controlling a terminal voltage of said first connection terminal means to substantially a power supply voltage of said second power supply path; and closing said second power supply path.