Hybrid DC Contactor Arc Prevention via Solid State Switch
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Solution Overview
Problem
Direct current contactors in vehicles face the challenge of arc formation when opening or closing contacts, leading to potential damage and reduced lifespan, with existing solutions like arc chutes and hermetically sealed containers being costly and complex.
Innovation Solution
A hybrid contactor combining mechanical main contacts with a high voltage solid state switch, providing a parallel current path to prevent arc formation by diverting current through the solid state switch when opening or closing the main contacts, with optional auxiliary contacts for additional safety and galvanic isolation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a hermetically sealed container is used to enclose the contacts, then arc formation is prevented, but manufacturing complexity and cost increase
Solution Approach 1:
The patent extracts the arc prevention function from the mechanical contact structure by introducing a separate solid state switch. The solid state switch is electrically connected in parallel with the mechanical contacts and handles the arc-prone switching operations, while the mechanical contacts only carry load current. This separation removes the harmful arc formation from the mechanical contact system without requiring hermetic sealing.
Solution Approach 2:
The solid state switch acts as an intermediary component between the control signal and the mechanical contacts. It provides a non-contact electrical path that prevents arc formation during switching operations. The solid state switch absorbs the electrical stress and arc energy that would otherwise damage the mechanical contacts, extending their lifespan without requiring complex protective enclosures.
2Reliability
If arc chutes are used to break the arc, then arc damage is reduced, but contactor size increases
Solution Approach 1:
The patent replaces the mechanical arc chute system with an electronic solid state switch. Instead of using physical structures to stretch and cool arcs, the solid state switch provides an alternative electrical path that prevents arc formation entirely. This substitution eliminates the need for large arc chute components and maintains compact contactor dimensions while achieving superior arc protection.
3Device complexity
If mechanical contacts are used alone, then结构简单性 is maintained, but arc formation causes damage and reduces lifespan
Solution Approach 1:
The patent segments the contactor into two functional parts: mechanical contacts for load carrying and solid state switches for switching operations. This segmentation allows each component to be optimized for its specific function - the mechanical contacts remain simple and robust for current conduction, while the solid state switch handles the complex arc prevention task. The overall structure remains relatively simple despite the added component, as the division of labor reduces stress on individual elements.
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 hybrid contactor effectively prevents arc formation, increases contactor lifespan, and reduces manufacturing complexity and cost, enabling reliable switching of high voltage DC current without the need for arc chutes or hermetic seals.
Implementation Method 1
The solid state switch provides a parallel current path to the main contacts
Implementation Method 2
When the main contacts are to be opened or closed, the solid state switch is closed, diverting current away from the contacts so that no arc is formed
Data Source
AI summary
An apparatus, and a method of opening and closing electrical power feed lines using a hybrid contactor, which combines a traditional set of mechanical main contacts with a high voltage solid state switch. The solid state switch provides a parallel current path around the main contacts. When the main contacts are to be opened or closed, the solid state switch is first closed, diverting current away from the main contacts to prevent arc formation when the main contacts are being opened or closed. Once the main contacts are opened or closed, the solid state switch is opened, as the parallel current path is no longer needed. Optional auxiliary contacts are connected in series with the solid state switch to provide galvanic isolation between an input terminal and an output terminal.