Low-Voltage Circuit Breaker Semiconductor Bypass Thermal Management
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Solution Overview
Problem
Conventional low-voltage protective switching devices face issues with high thermal loads and reduced lifespan due to high continuous or overcurrents, which are not effectively managed by existing semiconductor switches, leading to increased resistance and potential circuit breaker failure.
Innovation Solution
A low-voltage protective switching device with a mechanical bypass switch and semiconductor circuit arrangements, where a first semiconductor circuit is connected in parallel with the bypass switch, and a second semiconductor circuit is arranged in series, controlled by an electronic unit to manage currents and reduce self-heating through alternating switching and rapid shutdowns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a bypass relay with several serial contact points is used to handle overcurrents, then the circuit breaker can manage higher currents, but the resistance of the bypass relay increases significantly, leading to problematic thermal load and reduced circuit breaker life
Solution Approach 1:
The patent divides the current path into multiple parallel semiconductor circuit arrangements instead of using a single bypass relay with serial contacts. Each semiconductor arrangement handles a portion of the current, distributing the thermal load and reducing resistance-related heating while maintaining high current handling capacity
Solution Approach 2:
The patent replaces the mechanical bypass relay with solid-state semiconductor circuit arrangements. This substitution eliminates the high contact resistance inherent in mechanical serial contacts, reducing I²R losses and thermal loading on the bypass path, thereby extending circuit breaker life while maintaining overcurrent handling capability
2Power
If high continuous currents flow through the protective switching device, then the device can handle higher power loads, but self-heating increases, requiring larger device size and reducing semiconductor service life
Solution Approach 1:
The patent segments the current path into multiple parallel semiconductor circuit arrangements, distributing the continuous current across multiple paths. This reduces the current density and I²R losses in each individual path, thereby reducing self-heating while maintaining the ability to handle high total currents
Solution Approach 2:
The patent optimizes the local thermal characteristics by providing separate thermal management for each semiconductor circuit arrangement. The parallel configuration allows heat to be distributed across multiple localized areas rather than concentrated in a single bypass path, improving heat dissipation efficiency
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
This configuration maintains low self-heating, extends the lifespan of semiconductors, and enhances reliability by reducing thermal loads and preventing arc formation, allowing for smaller device size and improved switching efficiency.
Implementation Method 1
it leads to a problematic thermal load on the bypass relay and on the adjacent assemblies within the circuit breaker
Data Source
Figure 1~2
AI summary
In a low-voltage circuit breaker device (1) having at least one outer conductor path (2) and a neutral conductor path (5), wherein a mechanical bypass switch (8) is arranged in the outer conductor path (2), wherein a first semiconductor circuit arrangement (11) of the low-voltage circuit breaker device (1) is connected in parallel with the bypass switch (8), wherein a current measurement arrangement (12), which is connected to an electronic control unit (13) of the circuit breaker device (1), is arranged in the outer conductor path (2), it is proposed that a second semiconductor circuit arrangement (14) is arranged in the outer conductor path (2) in series with the bypass switch (8) and in parallel with the first semiconductor circuit arrangement (11) in terms of circuit technology, and that the electronic control unit (13) is configured, in the case of a current arising via the outer conductor path (2) that is greater than the rated current but lower than a trip overcurrent, to first switch on the first semiconductor circuit arrangement (11) , then to block the second semiconductor circuit arrangement (14), and subsequently to switch on the first semiconductor circuit arrangement (11) and the second semiconductor circuit arrangement (14) in alternation in a settable manner.