DC Interrupter with Segmented Switching Paths
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Solution Overview
Problem
Direct-current interrupters face challenges in minimizing size due to the need for large current-carrying capacity and high-speed switching to prevent arc formation and ensure efficient current interruption, leading to increased size and complexity.
Innovation Solution
A direct-current interrupter design incorporating a current-carrying path with a switch and a current-interrupting path, where a controller manages the flow using a combination of gas and vacuum switches, a commutation circuit, and a transient voltage suppression circuit to facilitate fast and efficient current commutation without relying on semiconductor circuit breakers, thereby minimizing size and power loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a direct-current interrupter uses a large capacity current-interrupting path to handle high currents, then the current interruption capability is improved, but the device size increases
Solution Approach 1:
The current interrupting function is divided into two separate paths: a current-carrying path with a first switch for normal operation, and a current-interrupting path with a second switch for interruption. This segmentation allows each path to be optimized independently, with the interrupting path only needing to handle the interruption moment rather than continuous high current, thereby reducing overall device size while maintaining interruption capability.
Solution Approach 2:
The first switch opens before the second switch during the interruption process. This preliminary action transfers the current to the current-interrupting path in advance, allowing the main current-carrying path to be disconnected first. This sequencing enables the interrupting path to handle the current transition smoothly without requiring excessive capacity, thus reducing device size.
2Object-affected harmful factors
If the switching speed is increased to prevent current increase during commutation, then the arc suppression is improved, but the device complexity increases
Solution Approach 1:
The switching operation is segmented into two distinct stages: first switch opening for path transition, and second switch opening for current interruption. This segmentation allows each switch to operate at optimized speeds for its specific function, with the first switch handling the commutation transition and the second switch handling the final interruption, thereby suppressing arcs without requiring both switches to operate at maximum speed simultaneously, reducing overall complexity.
Solution Approach 2:
The first switch performs a preliminary action by opening before the second switch, initiating the current transfer to the interrupting path. This preliminary commutation action reduces the current burden on the second switch and allows the system to prepare for interruption in advance, enabling faster effective switching without requiring overly complex high-speed switching mechanisms for both switches simultaneously.
3Reliability
If the current-interrupting path capacity is increased to handle large accident currents, then the current handling capability is improved, but the device size increases
Solution Approach 1:
The current handling function is segmented between two switches with different capacity requirements. The first switch in the current-carrying path handles normal high current flow, while the second switch in the current-interrupting path only needs to handle the transient interruption current. This segmentation allows the interrupting path components to be smaller since they don't need to continuously handle full load current, only the momentary interruption current.
Solution Approach 2:
The first switch opens in advance to transfer current to the interrupting path before the second switch opens. This preliminary action ensures that when the second switch opens for interruption, the current is already routed through the parallel path, allowing the interrupting path to handle the current transition with appropriate capacity without needing to simultaneously handle both full load and interruption demands, thus reducing required capacity and device size.
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 solution enables rapid and efficient current interruption with reduced power loss and device size, effectively addressing the challenge of arc suppression and current handling in direct-current systems.
Implementation Method 1
a vacuum valve having a movable electrode and a fixed electrode and capable of interrupting current flowing between the movable electrode and the fixed electrode
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A direct-current interrupter of an embodiment includes: a current-carrying path; a commutation circuit; a semiconductor circuit breaker; and a non-linear resistor. The current-carrying path passes a direct current and includes first and second switches. The second switch is connected in series to the first switch and has a withstand voltage lower than a withstand voltage of the first switch. The semiconductor circuit breaker and the non-linear resistor are connected in parallel to the current-carrying path.