Vacuum Interrupter Transverse Magnetic Field for DC Switching
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Solution Overview
Problem
State-of-the-art medium voltage vacuum interrupters are unable to switch DC currents effectively when the circuit voltage exceeds 50V, necessitating the development of a solution to enhance their arc voltage for reliable commutation.
Innovation Solution
A magnetic system is integrated with the vacuum interrupter to generate a magnetic field perpendicular to the arc, utilizing permanent magnets and/or coils to increase the arc voltage, enabling the commutation of DC currents to a parallel semiconductor path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a standard medium voltage vacuum interrupter is used, then the device structure remains simple and cost-effective, but the arc voltage remains limited to about 50V making DC current switching impossible above this voltage
Solution Approach 1:
The patent combines a vacuum interrupter with a magnetic field generating system (permanent magnets and/or coils) to create a hybrid DC switch. The magnetic system is integrated around the vacuum interrupter contacts, merging two functional elements into a single compact device that can handle DC currents at medium voltages.
Solution Approach 2:
The magnetic field acts as an intermediary between the vacuum interrupter and the DC current to be switched. By introducing a transverse magnetic field, the arc voltage is increased from 50V to several hundred volts, enabling the vacuum interrupter to commutate DC currents that would otherwise be impossible to switch.
2Reliability
If the arc voltage is increased to enable DC current commutation, then the switching capability is improved, but additional magnetic components increase the device complexity
Solution Approach 1:
The patent changes the physical parameters of the arc by introducing a magnetic field. The transverse magnetic field modifies the arc characteristics, increasing the arc voltage from 50V to several hundred volts through electromagnetic interaction with the arc plasma.
Solution Approach 2:
The hybrid DC switch uses a composite structure combining magnetic materials (permanent magnets, magnetic cores) with the vacuum interrupter components. This composite approach enables the magnetic field generation necessary for high voltage arc and DC current commutation.
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 effectively increases the arc voltage of a standard vacuum interrupter from about 50V to several hundred volts, facilitating reliable switching of DC currents in medium voltage applications without requiring additional arcing chambers.
Implementation Method 1
A magnetic system is integrated with the vacuum interrupter to generate a magnetic field perpendicular to the arc
Implementation Method 2
The magnetic system is configured to generate a magnetic field with magnetic flux lines that are directed through a gap between the movable contact and the fixed contact during the opening transition
Data Source
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AI summary
The present invention relates to a low voltage, medium voltage, or high voltage switch system, comprising: - a vacuum interrupter (10); and - a magnetic system (50); wherein the vacuum interrupter comprises a fixed contact (11) and a movable contact (12); wherein in a closed configuration of the switch system the vacuum interrupter is configured to maintain the movable contact in contact with the fixed contact; wherein in an opening transition of the switch system the vacuum interrupter is configured to move the movable contact away from the fixed contact; and wherein the magnetic system is configured to generate a magnetic field with magnetic flux lines that are directed through a gap between the movable contact and the fixed contact during the opening transition; and wherein an axis of the vacuum interrupter is directed through the centre of the fixed contact and through the centre of the movable contact, and wherein the magnetic flux lines are directed perpendicularly to the axis of the vacuum interrupter.