Solid State Circuit Interrupter With Fast Trip and Galvanic Isolation
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Solution Overview
Problem
Solid state circuit interrupters have not fully utilized their capabilities for faster tripping and face safety and wellness concerns compared to conventional mechanical circuit interrupters, indicating a need for improved design and functionality.
Innovation Solution
A circuit interrupter design that includes a current sensor, solid state switch module, gate driver with desaturation function, and analog trip circuit to rapidly interrupt current flow based on sensed thresholds, along with separable contacts and an electronic trip unit for galvanic isolation, enabling fast and controlled switching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If solid state components are used to switch current, then tripping speed is improved, but safety and wellness concerns worsen
Solution Approach 1:
The circuit interrupter is divided into two distinct switching systems: a solid state switch module for fast tripping and separable contacts for safe isolation. This segmentation allows each component to specialize in its strength while mitigating weaknesses
Solution Approach 2:
Separable contacts act as an intermediary between the solid state switch module and the load. They provide galvanic isolation and arc extinction, mediating the transition from fast solid state switching to safe mechanical isolation
2Speed
If solid state switch module is used, then current interruption speed is improved, but galvanic isolation capability worsens
Solution Approach 1:
The isolation function is separated from the solid state switch module and assigned to dedicated separable contacts with arc chutes. This allows the solid state module to focus on fast switching while the mechanical contacts handle isolation
Solution Approach 2:
Separable contacts serve as an intermediary that provides galvanic isolation and arc extinction, protecting against harmful factors that solid state components cannot address
3Measurement precision
If multiple sensing and control circuits are added, then monitoring capability is improved, but device complexity worsens
Solution Approach 1:
The current sensor serves multiple functions: providing normal sensor output for monitoring and generating over current detection output for protection. This multi-functionality reduces the need for separate sensing circuits
Solution Approach 2:
Multiple protection functions (overcurrent detection, desaturation detection, arc detection) are merged into a unified control system that coordinates the solid state switch module and separable contacts
Data Source
AI summary
A circuit interrupter including a current sensor having a normal sensor output and an over current detection output, a solid state switch module structured to have a closed state to allow current to flow through the circuit interrupter and an open state to interrupt current flowing through the circuit interrupter, a gate driver structured to control the solid state switch module including a desaturation function output, wherein the gate driver is structured to cause the solid state switch module to interrupt current flowing through the circuit interrupter when the DESAT function output changes to the on state, and an electronic trip circuit structured to output a trip signal to the gate driver when the normal sensor output reaches a first threshold level or the overcurrent detection output changes to the on state.