Fault Current Limiter with Trigger Device and Control Module

Solution Overview

Problem

Conventional fault current limiters are inadequate in generating sufficient repulsive force to effectively stop fault currents, leading to potential damage to electrical equipment due to insufficient current limitation.

Innovation Solution

A fault current limiter system comprising a trigger device, switches, a driver, a fixation unit, and a control module that utilizes a capacitor, protection relay, and controller to manage the flow of fault and normal currents, ensuring proper switching and limiting of fault currents through a path diversion mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If a conventional current limiter is used to limit fault current, then the fault current is limited to some extent, but the repulsive force generated is insufficient to stop the fault current effectively

Engineering Contradiction:

Improverepulsive forceVSAvoidfault current stopping capability

Core Design Contradiction:

ForceVSReliability

Solution Approach 1:

The patent divides the fault current path into multiple segments using a trigger device and switch. The trigger device separates the normal current path from the fault current path, and the switch can be opened to disconnect the fault current path entirely. This segmentation allows the system to not only limit but completely stop the fault current by creating distinct pathways and control points.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The fixation unit is pre-configured to fix the switch in the closed position during normal operation. When fault current is detected, the control module activates the fixation unit to open the switch, creating a predetermined failure mode that ensures the fault current is stopped. This preliminary setup of the fixation mechanism enables rapid response without complex real-time decision-making.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If a circuit breaker is used to prevent over-current, then the connection is broken to protect equipment, but a considerable time is required for detection and breaking

Engineering Contradiction:

Improveequipment protectionVSAvoiddetection and breaking time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The fixation unit is pre-configured to fix the switch in the closed position during normal operation. When fault current is detected, the control module activates the fixation unit to open the switch, creating a predetermined failure mode that ensures the fault current is stopped. This preliminary setup of the fixation mechanism enables rapid response without complex real-time decision-making.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent replaces the traditional mechanical over-current relay detection system with a control module that can detect fault current and activate the fixation unit. This substitution reduces the detection time from several periods to a much faster response, as the control module can process the fault detection and activate the switch opening mechanism more rapidly than mechanical relays.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If the fault current is divided by the trigger device, then the normal current path is protected, but the repulsive force generated by the divided fault current is insufficient

Engineering Contradiction:

Improvenormal current path protectionVSAvoidrepulsive force

Core Design Contradiction:

ReliabilityVSForce

Solution Approach 1:

The patent divides the fault current path into multiple segments using a trigger device and switch. The trigger device separates the normal current path from the fault current path, and the switch can be opened to disconnect the fault current path entirely. This segmentation allows the system to not only limit but completely stop the fault current by creating distinct pathways and control points.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The switch is extracted from the normal current path and placed in the fault current path, controlled by the fixation unit. This allows the fault current to be completely extracted from the system by opening the switch, rather than just being divided. The normal current path remains unaffected while the fault current path can be completely disconnected when needed.

Inventive Principle:

Principle #2Taking out (Extraction)

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 system effectively limits fault currents by diverting them through a specific path, preventing damage to equipment and ensuring accurate operation by distinguishing between fault and normal currents, thus enhancing the reliability of fault current management.

Implementation Method 1

a driver for opening a contact point contacted by the first switch by repulsive force generated by the fault current

Methodology Applied

Scientific EffectElectromagnetic force: Lorentz Force

Data Source

PatentUS8184420B2Control module and fault current limiter with function of opening and closing

Publication Date: 2012.05.22 LG INDUSTRIAL SYSTEMS CO LTD

AI summary

The present disclosure relates to a fault current limiter, comprising: a trigger device dividing a fault current to a path on which a normal current flows and to a path on which the fault current flows when the fault current is generated; a first switch connected in series to a rear end of the trigger device; a fixation unit for fixing an open/close state of the first switch; a driver for opening a contact point contacted by the first switch by repulsive force generated by the fault current in a case the fault current divided by the trigger device is inputted; and a control module for driving the fixation unit in order to fix the open/close state of the first switch in a case the fault current is generated.