Solid-State Bidirectional Switching for Fast Fault Interruption
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional power interrupters are slow to react to fault conditions due to their electromechanical construction, leading to potential hazardous fires, damage, and arc-flashes because they require several milliseconds to isolate fault conditions.
Innovation Solution
The development of solid-state power interrupter devices equipped with a solid-state bidirectional switch and control circuitry that includes driver circuitry for generating regulated DC voltage and fault detection circuitry to quickly identify and respond to fault conditions by switching off the power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional electromechanical power interrupters are used, then the device structure is simple and reliable, but the reaction time to fault conditions is slow (several milliseconds)
Solution Approach 1:
The patent replaces the electromechanical contact separation mechanism with a solid-state bidirectional switch that uses electronic control to interrupt power flow. The solid-state switch eliminates mechanical moving parts and uses semiconductor devices (such as MOSFETs or IGBTs) controlled by gate signals from the control circuitry, achieving microsecond-level response times compared to millisecond-level mechanical operation.
Solution Approach 2:
The control circuitry acts as an intermediary between the fault detection and the power interruption. When fault detection circuitry identifies a fault condition, it sends a control signal through the driver circuitry to the solid-state bidirectional switch, which then rapidly interrupts power flow. This intermediary control system enables precise timing and coordinated operation of the solid-state components.
2Loss of time
If conventional electromechanical power interrupters are used, then the manufacturing cost is lower, but the time to isolate fault conditions is delayed (several milliseconds)
Solution Approach 1:
The electromechanical components (moving contacts, springs, magnetic fields) are replaced with solid-state semiconductor devices that can be manufactured using standard integrated circuit fabrication processes. The bidirectional switch, driver circuitry, and control logic can be implemented on a single printed circuit board or integrated into a compact module, reducing assembly complexity despite the advanced electronics involved.
Solution Approach 2:
The control circuitry performs multiple functions: fault detection through current sensing, decision logic for trip conditions, and drive signal generation for the solid-state switch. The driver circuitry simultaneously provides gate drive signals and protects the control circuit from voltage spikes. This multi-functionality reduces the number of separate components needed, simplifying manufacturing.
3Reliability
If solid-state bidirectional switch with control circuitry is used, then the reaction time to fault conditions is rapid (microseconds), but the device complexity increases
Solution Approach 1:
The driver circuitry serves as an intermediary buffer between the low-voltage control circuitry and the high-voltage solid-state power switch. It provides galvanic isolation, voltage level translation, and current amplification, protecting the sensitive control electronics while enabling precise control of the high-power device. This intermediary layer manages the complexity by separating control and power functions.
Solution Approach 2:
The fault detection circuitry continuously monitors the load current and provides feedback to the control circuitry. When the current exceeds predetermined thresholds or exhibits fault patterns, the feedback triggers the control circuitry to activate the solid-state switch for interruption. This closed-loop feedback ensures reliable fault detection and response while simplifying the control logic through automatic threshold-based decision-making.
Data Source
AI summary
A power interrupter device includes a solid-state bidirectional switch and control circuitry to control the solid-state bidirectional switch. The bidirectional switch is connected between input and output terminals of the power interrupter device. The control circuitry includes driver circuitry and fault detection circuitry. The driver circuitry generates a regulated direct current (DC) voltage using current drawn from an input power source applied to the input terminal and applies the regulated DC voltage to a control input of the bidirectional switch. The fault detection circuitry is configured to sense a level of load current flowing in an electrical path between the input and output terminals, to detect an occurrence of a fault condition based on the sensed load current level, and to short the control input of the bidirectional switch to place the bidirectional switch in a switched-off state, in response to detecting the occurrence of a fault condition.