Reed Contact Earthing Module for Switchgear Fault Arc Quenching
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Solution Overview
Problem
Existing short circuit current detection systems for medium or high voltage switchgear are complex and expensive, requiring auxiliary power for accurate measurement and assembly, which increases costs and reduces system availability.
Innovation Solution
A short circuit detection device using reed contacts with adjustable orientation and distance from the conductor, combined with a photovoltaic cell to generate energy for triggering a fast earthing switch without auxiliary power, allowing for simple and cost-effective arc protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If accurate current measurement systems are used to detect short circuit currents, then detection precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces complex electronic current measurement systems with a magnetic field-based reed contact detection mechanism. The reed contact directly responds to the magnetic field generated by fault current in the busbar, eliminating the need for complex measurement electronics while maintaining reliable detection capability.
Solution Approach 2:
The patent employs inexpensive reed contacts as the detection element instead of expensive precision measurement instruments. The reed contact is a simple, low-cost component that reliably detects fault conditions without requiring complex support infrastructure.
2Reliability
If auxiliary power is provided for the control device, then detection reliability is improved, but system availability and cost are worsened
Solution Approach 1:
The detection system is completely passive and self-activating. The reed contact automatically responds to the magnetic field generated by fault current without requiring any external power supply. The fast earthing switch is triggered directly by the reed contact closure, eliminating the need for auxiliary power systems.
3Adaptability or versatility
If wiring is added for power supply to control device, then system functionality is improved, but assembly complexity and cost increase
Solution Approach 1:
The patent extracts and eliminates the power supply subsystem from the detection system. By using passive reed contacts that operate on magnetic fields alone, the design removes all associated wiring, power connections, and support infrastructure, dramatically simplifying the overall system.
4Speed
If fast earthing switch is triggered quickly, then fault arc quenching speed is improved, but energy storage system complexity increases
Solution Approach 1:
The fast earthing switch is pre-charged with energy from the capacitor bank during normal operation. When a fault is detected by the reed contact, the pre-charged capacitor immediately triggers the earthing switch, enabling extremely fast response without requiring complex real-time energy management systems.
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 efficient detection and quenching of fault arcs in switchgear panels without auxiliary power, reducing costs and improving system availability by utilizing reed contacts and photovoltaic cells to activate the earthing switch.
Implementation Method 1
The holder is configured to position the reed contact with respect to the longitudinal axis, such that when a magnitude of the current flow through the conductor exceeds a threshold current value the reed contact is configured to close
Implementation Method 2
A short circuit detection device using reed contacts with adjustable orientation and distance from the conductor, combined with a photovoltaic cell to generate energy for triggering a fast earthing switch
Data Source
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AI summary
The present invention relates to a short circuit current detection device for a medium voltage or high voltage switchgear. The short circuit detection device comprises a reed contact (20), and a holder (100). The holder is configured to hold the reed contact. The holder is configured to be mounted with a defined orientation to a conductor (10) of a switchgear. At a location where the holder is mounted the conductor has a longitudinal axis. The conductor is configured to enable a current (11) to flow through the conductor in a direction of the longitudinal axis. The holder is configured to position the reed contact with respect to the longitudinal axis, such that when a magnitude of the current flow through the conductor exceeds a threshold current value the reed contact is configured to close.