Multi-Circuit DC Breaker Layout for Fast Fault Current Limiting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing DC circuit breakers face challenges in quickly detecting failures in DC power grids, effectively limiting fault currents, and maintaining stability across various fault current ranges, especially in high-voltage direct current (HVDC) systems, due to issues with arc extinction and heat generation, limiting their economic viability and capacity.
Innovation Solution
A multi-circuit DC breaking system combining superconducting current-limiting modules, hybrid controllers, and multi-circuit breaking modules with parallel auxiliary circuits, utilizing vacuum interrupters and permanent magnet actuators to detect faults, limit fault currents, and distribute them across multiple circuits for rapid arc extinction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If semiconductor breaking is used, then fault current limiting is fast and stable, but economic burden is very large and heat generation problem occurs
Solution Approach 1:
The DC circuit breaker is divided into multiple auxiliary circuits with different current capacities connected in parallel. Each circuit can be independently controlled to break at different times, allowing the total breaking capacity to be distributed across multiple smaller, more economical semiconductor components rather than requiring a single large-capacity component.
Solution Approach 2:
The system dynamically selects and activates specific auxiliary circuits based on the magnitude of the fault current detected. The controller adjusts which circuits operate in real-time, optimizing the use of semiconductor components and reducing overall system cost while maintaining fast and stable fault current limiting performance.
2Ease of manufacture
If mechanical circuit breakers are used, then they are economical, but deterioration occurs due to arcing and they are only usable in very low ranges of voltage and current
Solution Approach 1:
The breaking system is segmented into multiple auxiliary circuits with progressively increasing current capacities. This allows the system to handle a wide range of fault currents from low to high magnitudes using a modular architecture, extending the usable voltage and current range while maintaining economical mechanical breaker components.
Solution Approach 2:
The multi-circuit breaking module serves multiple functions: it provides economical breaking for low-current faults using mechanical contacts, and can scale to handle high-current faults by activating additional auxiliary circuits. This universal design allows a single system to operate effectively across very low to very high voltage and current ranges.
3Device complexity
If single-circuit breaking is used, then structure is simple, but capacity cannot be easily increased and breaking operation is limited to specific fault current ranges
Solution Approach 1:
The breaking system is divided into multiple auxiliary circuits that can be independently controlled. This segmentation allows the system to maintain relative structural simplicity while enabling easy capacity expansion by adding or activating different combinations of auxiliary circuits to match various fault current magnitudes.
Solution Approach 2:
The controller dynamically determines which auxiliary circuits to activate based on the detected fault current magnitude. This dynamic operation allows a single multi-circuit module to adapt to different fault scenarios, providing breaking operations across a wide fault current range without requiring physically separate breaker systems for each current level.
4Productivity
If DC circuit breaker opens contact point, then circuit is broken, but arc is generated due to surge voltage and absence of current zero point
Solution Approach 1:
The auxiliary circuits are pre-configured with different current capacities and are selectively activated before the main circuit breaker opens. This preliminary action allows fault current to be diverted through appropriate auxiliary paths, reducing the surge voltage and arc energy when the main contacts open, thereby minimizing harmful arc generation and heat.
Solution Approach 2:
The auxiliary circuits serve as intermediary paths that handle the fault current in a controlled manner. By routing current through these intermediate circuits with appropriate impedance and capacity, the system mediates the energy release process, reducing the intensity and duration of arcs when main contacts separate, thus decreasing heat generation and damage risk.
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 solution enables quick detection and limitation of fault currents, reduces arc energy, and increases system capacity by distributing fault currents, enhancing the reliability and stability of DC power grid operations while reducing economic burdens and heat generation risks.
Implementation Method 1
a superconducting current-limiting module configured to detect a failure of the DC power grid through a phase transition and limit a maximum magnitude of a fault current
Implementation Method 2
in a contact point of the multi-circuit breaking module, a vacuum interrupter may be used to extinguish the arc generated during an opening/closing operation by vacuum
Data Source
AI summary
A multi-circuit DC breaking system is proposed. According to an exemplary embodiment of the present technique, there may be an advantage that by combining current-limiting technology and multi-circuit breaking technology, a failure may be quickly detected, a magnitude of a fault current may be firstly limited, and a breaking operation is performed, in a range of various fault currents, by distributing the fault currents to some circuits of multi-circuits configured in parallel, thereby easily increasing the capacity thereof.