Selective Circuit Breaker with Programmable Semiconductor Switch
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Solution Overview
Problem
Conventional selective circuit breakers require expensive designs to handle higher short circuit ratings than downstream breakers, leading to increased costs and complexity, while also failing to optimize protection characteristics such as let-through energy and fault current sensitivity.
Innovation Solution
A programmable selective circuit breaker with a short circuit current rating equal to that of downstream breakers, utilizing a semiconductor switch element like IGBT and a processing unit for controlled switching and reclosing, optimizing protection by minimizing let-through energy and fault current sensitivity differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional selective circuit breaker designs are used with higher short circuit ratings, then protection capability is improved, but device cost and complexity increase
Solution Approach 1:
The patent applies parameter changes by making the switching characteristic programmable rather than fixed. The circuit breaker can be configured with different switching curves and reclosing behaviors through software programming, allowing the same hardware design to adapt to different protection requirements and downstream breaker characteristics without physical redesign.
Solution Approach 2:
The patent implements universality by designing a circuit breaker that can function as both a protective device and a programmable control unit. The single device can operate in multiple modes (normal operation, reclosing, selective coordination) and can be programmed to work with different downstream breaker types and characteristics, reducing the need for multiple specialized breaker designs.
2Reliability
If conventional selective circuit breaker designs are used with higher short circuit ratings, then protection capability is improved, but device cost increases
Solution Approach 1:
The patent applies parameter changes by making the switching characteristic programmable rather than fixed. The circuit breaker can be configured with different switching curves and reclosing behaviors through software programming, allowing the same hardware design to adapt to different protection requirements and downstream breaker characteristics without physical redesign.
Solution Approach 2:
The patent applies copying by using a standardized circuit breaker design that can be replicated across different applications through software configuration rather than hardware modification. This allows mass production of identical hardware units that can then be programmed for specific applications, reducing manufacturing costs compared to producing custom-designed breakers for each application.
3Reliability
If programmable switching characteristic is implemented, then protection optimization is improved, but device complexity increases
Solution Approach 1:
The patent applies self-service by enabling the circuit breaker to automatically detect the downstream breaker type and characteristics, then programmatically adjust its own switching characteristic and reclosing behavior without external intervention. The device performs self-configuration and self-optimization based on detected system parameters.
Solution Approach 2:
The patent implements feedback by using the processing unit to continuously monitor system conditions, downstream breaker responses, and reclosing outcomes, then adjusting the switching characteristic and reclosing parameters based on this feedback to optimize protection performance and coordination with downstream devices.
4Ease of manufacture
If equal short circuit current rating is used for selective and downstream breakers, then cost-effectiveness is improved, but protection selectivity becomes more difficult
Solution Approach 1:
The patent applies dynamics by making the switching characteristic variable and programmable rather than fixed. Even with equal short circuit ratings, the selective breaker can dynamically adjust its switching curve and timing characteristics through programming to achieve proper selectivity coordination with downstream breakers, preventing unnecessary tripping while maintaining protection capability.
Solution Approach 2:
The patent applies parameter changes by making the switching characteristic programmable rather than fixed. The circuit breaker can be configured with different switching curves and reclosing behaviors through software programming, allowing the same hardware design to adapt to different protection requirements and downstream breaker characteristics without physical redesign.
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 approach allows for cost-effective circuit breaker designs with improved protection characteristics, reducing stress on the distribution network and enabling flexible programming for optimized installation, while ensuring reliable short circuit and overcurrent disconnections with minimal energy let-through.
Implementation Method 1
a semiconductor switch element IGBT connected parallel to the bypass switch SW1
Implementation Method 2
a short circuit and overcurrent detection unit connected to the processing unit for determining a short circuit situation or overcurrent situation
Implementation Method 3
a bypass switch SW1 in the live line, and a semiconductor switch element IGBT connected parallel to the bypass switch SW1
Data Source
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AI summary
Selective circuit breaker, in operation connectable between a main supply line and a downstream circuit breaker. The selective circuit breaker has a bypass switch in a supply line, and a controlled semiconductor switch connected in parallel to the bypass switch. A bypass switch off detection circuitry and a short circuit detection circuitry are provided for controlling the bypass switch and the semiconductor switch in accordance with a switching characteristic. The switching characteristic of the selective circuit breaker is programmable, and a short circuit current rating of the selective circuit breaker is substantially equal to a short circuit current rating of the downstream circuit breaker.