Hybrid Switch Control Circuit for Arc-Free Current Interruption
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Solution Overview
Problem
Existing hybrid switches face high manufacturing costs due to the need for customized components and the inability to use identical parts across different current-carrying capacities, and they suffer from arcing issues during current interruption.
Innovation Solution
A control circuit is introduced that can be used with a variety of hybrid switches, allowing for flexible operation by independently controlling a disconnecting element and a semiconductor switch through a specific temporal sequence of electric voltage application, reducing the need for customized components and minimizing arcing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the semiconductor switch is closed at the same time as the mechanical switch opens to avoid arcing, then arc-free operation is achieved, but an external voltage source is required and the semiconductor switch must be designed robustly for large currents
Solution Approach 1:
The hybrid switch uses its own arc voltage to trigger the semiconductor switch instead of requiring an external voltage source. The arc that forms when the mechanical switch opens provides the necessary voltage to turn on the semiconductor switch, making the system self-sufficient and eliminating the need for external power supply during switching operations.
Solution Approach 2:
The patent converts the harmful arc effect into a useful function. Instead of viewing the arc as purely detrimental, the invention utilizes the arc voltage generated during mechanical switch opening to trigger the semiconductor switch, thereby transforming a harmful phenomenon into a beneficial triggering mechanism that simplifies the overall system design.
2Object-affected harmful factors
If the semiconductor switch carries large current to prevent arcing, then arc-free operation is achieved, but manufacturing costs increase due to robust design requirements
Solution Approach 1:
The patent implements a dynamic switching strategy where the semiconductor switch operates in two distinct modes: initially carrying the full load current to prevent arcing, then transitioning to carry only a reduced current after the mechanical switch opens. This dynamic operation allows the semiconductor switch to be designed for lower current ratings while still achieving arc-free operation, thereby reducing manufacturing costs.
Solution Approach 2:
The semiconductor switch is pre-positioned in the closed state before the mechanical switch opens. This preliminary action ensures that when the mechanical switch begins to open, the semiconductor switch is already ready to immediately take over the current, preventing arc formation without requiring the semiconductor switch to continuously handle full load current.
3Reliability
If the time element duration is chosen long to prevent re-ignition of arc, then reliable current interruption is achieved, but loss of time increases
Solution Approach 1:
The patent employs a feedback mechanism where the control circuit monitors the state of the mechanical switch and the arc conditions in real-time. Based on this feedback, the control circuit dynamically adjusts the duration for which the semiconductor switch remains conductive, optimizing the balance between preventing arc re-ignition and minimizing switching time. This eliminates the need for conservative fixed time delays.
Solution Approach 2:
The switching time duration is made dynamic rather than fixed. The control circuit adjusts the conduction time of the semiconductor switch based on actual operating conditions, such as the rate of mechanical switch opening and arc characteristics. This dynamic adjustment allows for shorter switching times while maintaining reliable arc suppression, as the semiconductor switch remains conductive only as long as necessary.
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 control circuit reduces manufacturing costs by enabling the use of interchangeable components and effectively prevents arcing during current interruption, thereby enhancing the flexibility and efficiency of hybrid switches.
Implementation Method 1
the arc voltage above it (as a result of the arc) causes the semiconductor switch to conduct current
Implementation Method 2
There is an ionized gas between the switching contacts of the mechanical switch, which is created by the arc and is degraded over time
Data Source
AI summary
A control circuit of a hybrid switch comprising a main current path, which has a disconnecting element, and an auxiliary current path, which is connected in parallel with the main current path and has a semiconductor switch. The control circuit has a first terminal for the disconnecting element and a second terminal for the semiconductor switch and is configured to carry out a method in which a request for interrupting a current flow via the hybrid switch is recognized. A temporal sequence of an electrical voltage applied to each of the two terminals is chosen depending on the disconnecting element connected to the first terminal and the semiconductor switch connected to the second terminal. Furthermore, a hybrid switch is also provided.