Hybrid DC Disconnector Using Arc Commutation for Galvanic Isolation
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Solution Overview
Problem
Existing disconnecting devices for direct current interruption face issues with mechanical switches wearing out quickly due to arcs and semiconductor switches causing power losses without ensuring galvanic isolation for personal protection.
Innovation Solution
A hybrid circuit breaker with a magnetic trigger and semiconductor electronics in parallel, where the semiconductor electronics are current-blocking when closed and current-conducting when triggered, utilizing arc energy for operation and ensuring galvanic isolation by connecting in series with protective switches.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If mechanical switches are used for load disconnection, then galvanic isolation is achieved, but the switching contacts wear out quickly due to arc generation
Solution Approach 1:
The disconnecting device is divided into two functional segments: a mechanical circuit breaker that provides galvanic isolation and arc containment, and semiconductor electronics that provide a low-resistance current path during arcing. This segmentation allows each component to optimize its specific function without compromising the other.
Solution Approach 2:
The semiconductor electronics act as an intermediary component between the mechanical switch and the load. When the mechanical switch opens and generates an arc, the semiconductor electronics provide an alternative current path that分流s the arc current, reducing the burden on the mechanical contacts and extending their service life while maintaining galvanic isolation.
2Loss of energy
If high-performance semiconductor switches are used for load disconnection, then power losses are reduced, but galvanic isolation and personal protection are not ensured
Solution Approach 1:
The invention merges the advantages of mechanical switches (galvanic isolation, arc containment) and semiconductor switches (low power losses, high performance) into a single hybrid system. The mechanical circuit breaker provides galvanic isolation when closed, while the semiconductor electronics provide low-resistance current conduction during arc events, achieving both low power losses and galvanic isolation simultaneously.
3Device complexity
If semiconductor electronics are used without additional energy source, then device complexity is reduced, but current blocking capability when closed must be maintained
Solution Approach 1:
The semiconductor electronics are designed to be self-sufficient without requiring external energy sources. They utilize the arc voltage generated when the mechanical switch opens to automatically activate and conduct current during the arcing period. This self-service mechanism maintains current blocking capability when closed while avoiding the complexity of additional energy storage devices or power supplies.
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 hybrid circuit breaker effectively interrupts direct current without power losses and ensures galvanic isolation, reducing wear on mechanical switches and minimizing arc-related issues, achieving reliable and efficient DC interruption.
Implementation Method 1
an arc generated when the switch contacts of the circuit breaker(s) of the circuit breaker assembly open
Implementation Method 2
a first current-carrying circuit breaker with a magnetic trip
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
The invention relates to a disconnecting device (1) for interrupting the direct current between a direct current source (UDC), in particular in the DC voltage range between 300VDC and 1500VDC and/or in the rated current range between 4A and 250A, and a load (3), comprising a circuit breaker arrangement (5, 6, 8) having at least one circuit breaker (5) with a magnetic trip (12) and a semiconductor electronics (10) connected in parallel to the at least one circuit breaker (5), which is current-blocking when the circuit breaker arrangement (5, 6, 8) is conducting and is at least briefly current-conducting when the circuit breaker arrangement (5, 6, 8) is tripping, in that when the circuit breaker arrangement (5, 6, 8) trips the current (I), in particular an arc current generated as a result of an arc, is commutated from the at least one circuit breaker (5) to the semiconductor electronics (10).