Solid-State Circuit Breaker Switching Sequence Using Dual Micro-Switches
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Solution Overview
Problem
Existing solid-state circuit breakers face challenges in ensuring that the mechanical switch is turned on before the electronic switch during power-up and turned off after power-down, while maintaining reliable operation, especially in high voltage DC applications.
Innovation Solution
Incorporating a handle micro-switch and a contact micro-switch to detect the state of the handle and movable contact, allowing the mechanical switch to be turned on first when switching from off to on and the electronic switch to be turned off first when switching from on to off, with an electrically driven tripping unit for controlled switching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If micro-switches are added to detect handle and contact states, then switching sequence control is improved, but device complexity increases
Solution Approach 1:
The patent implements feedback control by using the handle micro-switch and contact micro-switch to detect the current state of the mechanical switch, then using this feedback information to control the electronic switch timing. The control unit receives signals from both micro-switches and automatically adjusts the switching sequence, creating a closed-loop control system that ensures reliable operation without requiring complex manual intervention.
Solution Approach 2:
The patent introduces micro-switches as intermediary devices that mediate between the mechanical switch components and the electronic control system. These micro-switches convert mechanical position information into electrical signals that can be processed by the control unit, serving as an interface layer that simplifies the overall control architecture while improving switching sequence reliability.
2Reliability
If electronic switch is turned off first during power-down, then breaking ability is improved, but risk of overcurrent increases
Solution Approach 1:
The patent applies preliminary action by having the electronic switch turn off first before the mechanical switch opens. This preliminary disconnection of the electronic switch prevents current from flowing when the mechanical contacts separate, eliminating the risk of overcurrent and arc generation. The control unit coordinates this sequence by detecting the power-down signal and automatically executing the predetermined sequence where the electronic switch opens first, followed by the mechanical switch.
Data Source
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AI summary
The present disclosure discloses a solid-state circuit breaker including an electronic switch and a mechanical switch connected in series, the mechanical switch includes: a handle micro-switch, configured to be actuated upon the handle rotating to the on position and released upon the handle leaving the on position; a contact micro-switch, installed to the housing and configured to be actuated upon the movable contact moving to a closed position and released upon the movable contact leaving the closed position. By detecting a state of the handle micro-switch and a state of the contact micro-switch, it is achieved that, upon the solid-state circuit breaker being switched from off to on, the mechanical switch is turned on first, and then the electronic switch is turned on, upon the solid-state circuit breaker being switched from on to off, the electronic switch is turned off first, and then the mechanical switch is turned off.