Arc-Free DC Circuit Breaker Using Magnetic Induction Transfer

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Solution Overview

Problem

Current high-voltage DC circuit breakers are inadequate for breaking short-circuit fault currents and have limited breaking speed, relying on insufficient theoretical foundations and experimental data, leading to delayed development and increased costs due to the need for repeated tests.

Innovation Solution

An arc-free DC circuit breaker combining magnetic induction transfer and resistive current-limiting, utilizing a bridge circuit with an induction module and over-voltage protection to achieve fast switching and current limiting, reducing the need for full-controlled power electronic devices and complex cooling systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If full-controlled power electronic devices are used to realize rapid transfer and current breaking, then breaking speed is improved, but device complexity and cost increase significantly

Engineering Contradiction:
Improvebreaking speedVSAvoiddevice complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The circuit breaker is divided into two functional modules: a magnetic induction transfer module for rapid current transfer and a resistive current-limiting module for current suppression. This segmentation allows each module to be optimized independently, reducing overall device complexity while maintaining high breaking speed through the magnetic induction mechanism.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A magnetic induction transfer module acts as an intermediary mechanism between the power source and the load, enabling rapid current transfer without requiring full-controlled power electronic devices. The magnetic induction mechanism provides the fast response needed for high breaking speed while simplifying the overall device architecture.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If full-controlled power electronic devices are used, then current breaking capability is improved, but cooling system complexity increases

Engineering Contradiction:
Improvecurrent breaking capabilityVSAvoidcooling system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The magnetic induction transfer module uses simple magnetic components and resistors that do not require complex cooling systems, replacing the need for expensive full-controlled power electronic devices with expensive thermal management infrastructure. The resistive current-limiting module provides reliable current breaking without generating the heat that would require complex cooling.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Adaptability or versatility

If traditional active injection current method is used, then bidirectional current breaking is achieved, but breaking speed is limited

Engineering Contradiction:
Improvebidirectional current breakingVSAvoidbreaking speed
Core Design Contradiction:
Adaptability or versatilityVSSpeed

Solution Approach 1:

The magnetic induction transfer module dynamically responds to current direction changes, automatically adjusting the transfer path for bidirectional current breaking. The rapid magnetic induction mechanism provides both bidirectional capability and high breaking speed, overcoming the speed limitation of traditional active injection methods.

Inventive Principle:
Principle #15Dynamics

4Reliability

If repeated tests are conducted for product development, then reliability is improved, but development time and cost increase

Engineering Contradiction:
Improveproduct reliabilityVSAvoiddevelopment time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The magnetic induction transfer mechanism replaces complex mechanical switching systems with a faster magnetic field-based transfer mechanism. This substitution not only improves breaking speed and reliability but also reduces the need for repeated testing to validate mechanical switch performance, thereby reducing development time.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 rapid, arc-free current breaking with improved voltage withstanding capability, reducing the usage of IGBT devices by 75% and eliminating the need for complex cooling systems, while enhancing reliability and feasibility.

Implementation Method 1

an arc-free DC circuit breaker combining magnetic induction transfer and resistive current-limiting is provided. By using an induction module to quickly transfer current to capacitors and resistors

Methodology Applied
Scientific EffectMagnetic induction: Electromagnetic Induction

Implementation Method 2

current may be limited under a certain level through resistive current-limiting

Methodology Applied
Scientific EffectResistive heating: Joule Heating

Data Source

PatentEP3321948B1DC circuit breaker based on combination of damping circuit and magnetic induction commutation circuit
Publication Date: 2020.08.12 XI AN JIAOTONG UNIV
  • EP3321948B1 patent drawingFigure 1
  • EP3321948B1 patent drawingFigure 2
  • EP3321948B1 patent drawingFigure 3

AI summary

The present disclosure provides an arc-free DC circuit breaker that combines magnetic induction transfer and resistive current limiting. The circuit breaker comprises a main current circuit and a transfer current circuit. The transfer current circuit has a bridge structure; with a group of unidirectional components having a breaking function, bidirectional current breaking is implemented, such that compared with the prior art, usage of the turn-off devices may be reduced to half. By controlling action sequences of the trigger gap, high-speed switch, and power semiconductor, fast switching arc-free opening of the main current circuit is implemented; meanwhile, the breaking capability of the circuit breaker is significantly improved. By virtue of the current limiting module circuit inside the transfer current circuit, the present disclosure quickly limits short-circuit fault current, and then reduces the number of parallel groups of full-controlled devices of the breaking module circuit. Compared with the existing circuit breaker structures, usage of turn-off devices and cost of the circuit breaker may be significantly reduced.