DC Circuit Breaker Commutation for Fast Re-Closing
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Solution Overview
Problem
Conventional DC circuit breakers face issues with high cost, large volume, and design contradictions in achieving fast re-closing functions due to slow charging times and the need for additional capacitors or external devices to restore commutation capacitor voltage.
Innovation Solution
A DC circuit breaker device with a commutation module comprising a commutation capacitor and switch branches, controlled by a module to charge/discharge to predefined polarity and voltage, allowing fast re-closing and arc extinction, using a simple structure with semiconductor switches and optional arresters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional DC circuit breaker designs are used to achieve fast re-closing function, then the re-closing capability is improved, but the device complexity, volume, and cost increase due to additional capacitors or external charging devices
Solution Approach 1:
The patent combines the commutation capacitor with the existing circuit breaker structure, eliminating the need for separate external charging devices or additional capacitors. The capacitor is integrated into the breaker body and charged through the circuit breaker's own switching operations, merging multiple functions into a unified structure that reduces overall device complexity while maintaining fast re-closing capability
Solution Approach 2:
The circuit breaker system charges its own commutation capacitor using its inherent switching operations and circuit configuration. The capacitor is charged through the commutation switch and circuit inductance during normal breaking operations, eliminating the need for external charging sources and reducing device complexity while enabling fast re-closing functionality
2Speed
If conventional DC circuit breaker designs are used to achieve fast re-closing function, then the re-closing capability is improved, but the device volume increases due to additional capacitors or external devices
Solution Approach 1:
The commutation capacitor is integrated directly into the circuit breaker structure rather than being mounted as a separate external component. This merging of the capacitor with the breaker body significantly reduces the overall device volume by eliminating the need for additional mounting space and external connections, while still providing the necessary capacitance for fast re-closing operations
Solution Approach 2:
The patent implements a nested arrangement where the commutation capacitor is positioned within the existing circuit breaker housing and structural framework. The capacitor is nested among other breaker components, utilizing the available internal space efficiently and reducing the external volume required for the overall device while maintaining all necessary functional clearances
3Speed
If conventional DC circuit breaker designs are used to achieve fast re-closing function, then the re-closing capability is improved, but the manufacturing cost increases due to additional capacitors or external devices
Solution Approach 1:
The patent merges the commutation capacitor with the circuit breaker assembly, allowing both components to be manufactured and assembled as a single integrated unit. This eliminates the need for separate procurement, mounting, and wiring of external charging devices or additional capacitors, significantly reducing manufacturing complexity and cost while maintaining fast re-closing performance
Solution Approach 2:
The circuit breaker is designed to serve multiple functions: it performs the primary current interruption, charges the commutation capacitor, and enables fast re-closing operations all through its inherent switching mechanism. This multi-functionality eliminates the need for dedicated external charging devices or additional capacitors, reducing the total component count and manufacturing cost while achieving the desired re-closing speed
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
Enables fast connection/disconnection and arc extinction with a compact, cost-effective design, overcoming the limitations of conventional methods by efficiently managing capacitor voltage for quick re-closing.
Implementation Method 1
a commutation module connected in parallel with the first circuit breaker and comprising a commutation capacitor, a commutation switch module and a commutation inductor connected in series
Implementation Method 2
a commutation module connected in parallel with the first circuit breaker and comprising a commutation capacitor, a commutation switch module and a commutation inductor connected in series
Data Source
AI summary
A DC circuit breaker device is provided, including: a circuit breaker module including a first circuit breaker and a second circuit breaker connected in series with the first circuit breaker; a commutation module connected in parallel with the first circuit breaker and including a commutation capacitor, a commutation switch module and a commutation inductor connected in series; the commutation switch module including a commutation switch positive branch and a commutation switch negative branch; and a control module coupled to the circuit breaker module and the commutation module, and configured to control the switching on/off of the commutation switch positive branch and the commutation switch negative branch after the first circuit breaker is re-closed. A method of controlling a DC circuit breaker is also provided.