Spark Gap Trigger Electrode Structure to Block Premature Firing
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Solution Overview
Problem
Existing spark gap firing arrangements using plasma jets for rapid firing are prone to premature aging due to low-energy overvoltage events triggering the entire spark gap, leading to unnecessary activation and potential damage.
Innovation Solution
An arrangement where a trigger electrode forms a sandwich structure with an insulating layer and a layer of lower conductivity, allowing for an energetic threshold to be set such that low-energy overvoltage events are discharged without firing the main spark gap, and only exceeding this threshold triggers the discharge, using an integrated electrical component like a miniaturized resistor to determine the threshold and control the response.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a trigger electrode is connected to one of the main electrodes to enable rapid firing, then the firing speed is improved, but the spark gap becomes susceptible to premature activation by low-energy overvoltage events
Solution Approach 1:
The trigger circuit is segmented into two separate paths: a low-impedance path for rapid response to high-energy events, and a high-impedance path that requires higher energy to activate. This segmentation allows the system to distinguish between harmful low-energy noise and genuine high-energy threats, preventing premature activation while maintaining fast response capability.
Solution Approach 2:
Different regions of the trigger electrode structure are assigned different electrical properties. The first region provides a direct low-impedance connection for rapid firing, while the second region introduces higher impedance to filter out low-energy disturbances. This local differentiation of electrical characteristics enables simultaneous achievement of fast response and noise immunity.
2Reliability
If an ignition transformer is used to generate high firing voltage, then the breakdown voltage is sufficient to fire the spark gap reliably, but the installation space and device complexity increase
Solution Approach 1:
The ignition transformer is extracted and removed from the system. Instead of using a transformer to generate high voltage, the patent employs a direct trigger electrode connection that utilizes the existing high voltage present during overvoltage events. This extraction eliminates the complexity and space requirements of the transformer while maintaining reliable spark gap firing capability.
Solution Approach 2:
The system uses its own high voltage during overvoltage events to trigger the spark gap, rather than requiring an external ignition transformer. The trigger electrode directly utilizes the inherent high voltage present in the system, making the system self-sufficient and eliminating the need for additional voltage transformation equipment.
3Device complexity
If the trigger electrode is in permanent electrical contact with a main electrode, then galvanic isolation is eliminated and simpler connection is achieved, but a voltage-switching element is required and control precision is reduced
Solution Approach 1:
The electrical connection of the trigger electrode is made dynamic rather than static. The connection impedance changes based on the operating conditions: during normal operation, the high-impedance path prevents activation, but during high-energy overvoltage events, the low-impedance path enables rapid firing. This dynamic impedance adjustment provides both simple physical connection and precise operational control.
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
Prevents premature aging of surge arresters by ensuring only high-energy overvoltage events trigger the spark gap, allowing for controlled and efficient firing while minimizing energetic loading on other components.
Implementation Method 1
The layer dielectric of the sandwich structure is represented as a series connection of a first partial capacitance with the dielectric of the insulating section and a second partial capacitance with the material of lower conductivity as a dielectric, wherein the partial capacitances are selected to be very low.
Implementation Method 2
The material M of the sandwich structure possesses an often worse conductivity than the material of one of the main electrodes. The ignition arc is extended via the thickness of the layer made of the material M.
Implementation Method 3
This beam results in a strong and fast purposeful movement of ionized gases and charge carriers. This transport is used in order to significantly accelerate the firing of the main line between the main electrodes
Data Source
AI summary
The invention relates to an arrangement for firing spark gaps with a trigger electrode which is located at or in one of the main electrodes and which is insulated from this main electrode, wherein the trigger electrode can be electrically connected to a further main electrode via at least one voltage-switching or voltage-monitoring element and there is an air gap between the trigger electrode and the further main electrode, wherein the trigger electrode forms a sandwich structure with an insulating layer and a layer made of a material with lower conductivity than the material of one of the main electrodes. Moreover, the insulating layer is designed as a thin foil or lacquer layer and the layer made of the material of lower conductivity is in contact with one of the main electrodes or rests on it. According to the invention, for discharging energetically weak overvoltage events without response of the spark gap formed between the main electrodes, the insulating layer of the sandwich structure is interrupted outside the firing area and/or an electrical component which influences the response behavior is connected between the trigger electrode and the associated main electrode.