Solid-State Circuit Interrupter With Three-Level Trip Logic
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Solution Overview
Problem
Existing solid state circuit interrupters lack optimal utilization of their faster tripping capabilities and pose safety and wellness concerns compared to conventional mechanical circuit interrupters.
Innovation Solution
A circuit interrupter with a current sensor, solid state switch module, gate driver, and analog trip circuit that employs a three-level interruption logic using DESAT, OCD, and normal sensor outputs to achieve rapid current interruption within microseconds, along with galvanic isolation via separable contacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional air circuit breakers are used, then high interrupting capability is achieved, but frequent mechanical operation causes wear and contamination leading to failure
Solution Approach 1:
The patent replaces the mechanical operation system of conventional air circuit breakers with an electronic solid-state switching system. The circuit breaker uses electronic sensors to detect overcurrent conditions and electronic switches (such as thyristors or transistors) to interrupt the circuit, eliminating mechanical moving parts that are subject to wear and contamination. This substitution maintains high interrupting capability while dramatically improving reliability by removing the mechanical failure modes.
Solution Approach 2:
The patent changes the operational parameters from mechanical movement to electronic signal processing. Instead of mechanically opening and closing contacts, the system uses electronic parameter changes in semiconductor devices to achieve circuit interruption. This parameter change enables the circuit breaker to respond to overcurrent conditions through electronic control signals, eliminating the wear and contamination issues associated with mechanical operation while maintaining the required interrupting capability.
2Adaptability or versatility
If vacuum circuit breakers are used, then maintenance-free operation is achieved, but they are unsuitable for DC applications
Solution Approach 1:
The patent creates a universal circuit breaker design that can handle both AC and DC applications through electronic switching. The solid-state switching devices (thyristors, transistors, or IGBTs) can be controlled to interrupt both alternating and direct current, making the circuit breaker adaptable to multiple application types. This electronic universality replaces the vacuum breaker's limitation to AC-only operation while maintaining the maintenance-free advantage.
Solution Approach 2:
By replacing the vacuum arc extinction mechanism with electronic solid-state switching, the patent achieves maintenance-free operation that is not limited by current type. The electronic switches can be precisely controlled to interrupt DC current by controlling the switching timing and duration, eliminating the fundamental limitation of vacuum breakers while preserving their maintenance-free operational characteristic.
3Adaptability or versatility
If solid state circuit interrupters with mechanical moving parts are used, then DC circuit interruption is achieved, but wear and contamination from mechanical operation occurs
Solution Approach 1:
The patent replaces mechanical moving parts with solid-state electronic switching devices to achieve DC circuit interruption without wear or contamination. The electronic switches (such as IGBTs or MOSFETs) are controlled by electronic signals to interrupt DC current, eliminating the mechanical contact wear and contamination issues while maintaining the ability to handle DC applications. This substitution preserves DC capability while removing the reliability-degrading mechanical elements.
4Productivity
If circuit breakers with many mechanically operated moving parts are used, then circuit interruption capability is achieved, but failure from wear and contamination increases
Solution Approach 1:
The patent replaces mechanically operated moving parts with solid-state electronic switching to maintain circuit interruption capability while eliminating wear and contamination. The electronic switching devices can interrupt circuits with the same or greater capability than mechanical breakers but without the associated wear mechanisms. This substitution directly addresses the failure rate issue by removing the mechanically operated components that are prone to wear and contamination.
Solution Approach 2:
The solid-state circuit interrupter uses electronic control systems that can detect and respond to circuit conditions without mechanical intervention. The electronic sensors and control circuits continuously monitor the circuit state and automatically trigger the solid-state switches when overcurrent conditions are detected, eliminating the need for mechanical moving parts while maintaining full circuit interruption capability and reducing failure rates.
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
Enables faster current interruption times than digital protection, reduces bounce arcs, and enhances safety by ensuring controlled switching states, thereby improving the performance and reliability of solid state circuit interrupters.
Implementation Method 1
a current sensor to detect an overcurrent condition
Implementation Method 2
a solid state switch having a control electrode, the solid state switch to interrupt a flow of current across the solid state switch in response to a control signal
Data Source
Figure 1
Figure 2
Figure 3A
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.