Series Circuit Breaker Coordination With Arc-Light Selective Tripping
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrical protection devices struggle to simultaneously achieve extreme breaking performance, total selectivity, and ultra-fast protection in high-power low-voltage applications, particularly in auxiliary panels of very high power boats, due to incompatibilities between filiation and selectivity for currents above 525V.
Innovation Solution
A set of electrical protection devices with a first circuit breaker and multiple downstream circuit breakers, featuring adjustable long-time and short-time tripping curves, optical sensors to discriminate arc light, and pyrotechnic propellants for ultra-rapid tripping, ensuring coordinated protection and selective tripping based on current and light measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional electrical protection devices are used in high-power low-voltage applications, then breaking performance can be achieved, but selectivity between stages becomes incompatible for currents above 525V
Solution Approach 1:
The protection system is divided into two distinct stages: a first circuit breaker for the upstream network and multiple second circuit breakers for downstream networks. Each stage has independently adjustable tripping characteristics, allowing selective coordination. The first circuit breaker handles general protection while second circuit breakers provide localized protection, enabling both high breaking performance and stage selectivity in high-power applications.
Solution Approach 2:
The tripping characteristics of both first and second circuit breakers are made dynamically adjustable through electronic triggers with programmable inverse-time and short-time curves. This dynamic adjustability allows the protection devices to adapt to different operating conditions and fault scenarios, maintaining selectivity across various current levels including high-power applications above 525V.
2Speed
If instantaneous tripping is implemented for ultra-fast protection, then response time is reduced, but false tripping may occur due to arc light interference
Solution Approach 1:
An optical sensor acts as an intermediary between the arc light and the electronic trigger. The sensor detects arc light characteristics and provides this information to the trigger, which uses it to distinguish between normal arc light during operation and abnormal arc light indicating a fault. This intermediary system enables ultra-fast tripping response while preventing false tripping by providing contextual information about the electrical state.
Solution Approach 2:
The optical sensor continuously monitors arc light and provides feedback to the electronic trigger. The trigger combines this optical feedback with current sensor data to make intelligent tripping decisions. This feedback mechanism allows the system to respond ultra-fast to genuine faults while filtering out normal operational conditions that would otherwise cause false tripping.
3Adaptability or versatility
If adjustable tripping curves are implemented for selective coordination, then selectivity is improved, but device complexity increases
Solution Approach 1:
Both first and second circuit breakers incorporate universal electronic triggers with programmable inverse-time and short-time tripping curves. This multi-functionality allows a single device design to handle various protection scenarios through software configuration rather than hardware variation. The adjustable parameters are organized in standardized groups, simplifying the coordination process while maintaining comprehensive selectivity capabilities.
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
The solution enables extreme breaking performance, total selectivity, and ultra-fast protection in high-power low-voltage systems by coordinating tripping mechanisms to manage high currents and arc faults effectively, minimizing external manifestations and optimizing energy distribution.
Implementation Method 1
an optical sensor (9) capable of discriminating an arc light
Implementation Method 2
the aforementioned upstream circuit breaker includes a pyrotechnic propellant intended to allow ultra-rapid tripping in the presence of an inter-phase arc fault
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to a set of two-level electrical protection devices connected in series, the first level comprising a circuit breaker referred to as the primary or upstream circuit breaker, the second level comprising one or more circuit breakers referred to as secondary or downstream circuit breakers (8), mounted in parallel with each other. This set is characterized in that the trip unit of the upstream circuit breaker (1) does not include instantaneous protection means but comprises, on the one hand, a first tripping chain allowing adjustment of the long-delay tripping curve in reverse time, as well as the short-delay tripping curve with a non-tripping time, and on the other hand, a second tripping chain comprising an optical sensor (9) capable of discriminating light between 300 and 450 nm by eliminating visible and infrared light.in order to eliminate the characteristic light of gas jets emitted by the so-called downstream circuit breaker(s) (8) during a power outage, and means for simultaneously measuring the current level and the maximum threshold of light emitted at the busbars, this second tripping chain being capable of triggering the upstream circuit breaker (1) when the current exceeds a predetermined value and the emitted light exceeds a predetermined threshold of emitted light.