Bypass Fuse Circuit for DC Cable Short-Circuit Arc Extinction
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Solution Overview
Problem
Existing electrical propulsion systems face challenges in managing short circuits in power supply cables, leading to electric arcs that are difficult to extinguish, which can damage the system and require additional mass and volume due to overdimensioning or resistive components.
Innovation Solution
A bypass circuit with a low-rating contactor and fuse is installed in parallel to the high-voltage DC power supply line, allowing quick diversion of current to extinguish the electric arc without increasing mass or volume significantly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional fuse protection system is used in electrical propulsion systems, then the system can protect against short circuits, but the electric arc cannot be extinguished quickly and the system mass increases due to overdimensioning or additional components
Solution Approach 1:
The protection function is segmented into two independent circuits: the main power circuit with fuse F1 for battery protection, and a separate bypass circuit with fuse F2 specifically dedicated to arc extinction. This segmentation allows each fuse to be optimized for its specific function without overdimensioning, reducing overall system mass while improving arc extinction capability.
Solution Approach 2:
The bypass circuit acts as an intermediary path that diverts current away from the fault location during a short circuit event. By providing this intermediate current path through contactor K3 and fuse F2, the system can extinguish arcs more effectively without requiring the main power circuit components to be overdimensioned for arc suppression.
2Reliability
If overdimensioning of the load is performed to manage regeneration energy, then the system can handle regeneration energy, but the load size and system mass increase
Solution Approach 1:
The regeneration energy management function is extracted from the main motor load and handled separately by the bypass circuit. The bypass circuit with contactor K3 and fuse F2 is specifically designed to manage regeneration energy and extinguish arcs, allowing the motor to be sized for its primary propulsion function without the additional mass burden of overdimensioning for energy management.
3Reliability
If additional resistive dissipation equipment is installed to dissipate regeneration energy, then the system can dissipate regeneration energy, but the system volume and mass increase significantly
Solution Approach 1:
The bypass circuit uses the existing motor and electrical distribution network infrastructure to dissipate regeneration energy. Instead of adding dedicated resistive dissipation equipment, the system utilizes the motor's back-EMF and the bypass circuit path to naturally manage and dissipate regeneration energy, significantly reducing the volume and mass of additional equipment required.
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
Effectively extinguishes electric arcs within milliseconds, preventing further damage and maintaining system functionality without the need for bulky components.
Implementation Method 1
the fuse F2 has melted
Implementation Method 2
a contactor K3 and a fuse F2 connected in series
Implementation Method 3
an electric arc supplied by the current mainly provided by the battery will be created
Data Source
AI summary
A device for protecting against a short-circuit occurring on a high-voltage DC power supply line between a DC source and an active load, the device including a bypass circuit formed of a contactor K3 and a fuse F2 connected in series and set up parallel to the active load via a line independent of the high-voltage DC power supply line, the bypass circuit being configured such that most of the current passes through it once the fuse F2 has melted.