Dual-Gate Bidirectional Switch Fault Detection Without Current Interruption
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing switch systems cannot effectively diagnose the state of bidirectional switches, particularly dual-gate bidirectional switches, due to the absence of a common connection node, which limits their ability to detect short-circuit or open-circuit failures.
Innovation Solution
A switch system comprising a bidirectional switch with a first and second gate, connected to respective gate driver circuits, and decision units that determine the state of each gate based on threshold voltages, allowing for the detection of abnormal states in both gates without interrupting the current flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a diagnosis circuit applies voltage to a common connection node to detect short-circuit failures, then the ability to detect failures is improved, but this method cannot be applied to bidirectional switches without a common connection node
Solution Approach 1:
The patent divides the bidirectional switch into two separate gate systems (first gate and second gate) with independent driver circuits and diagnosis circuits. Each gate can be diagnosed independently by applying voltage to its respective gate terminal, allowing the diagnosis method to work for bidirectional switches without common connection nodes.
Solution Approach 2:
The diagnosis circuit is designed to be universal by accommodating both bidirectional switches with common connection nodes and those without. The circuit can apply voltage to either the first gate or second gate depending on the switch configuration, making it adaptable to different switch types while maintaining failure detection capability.
2Measurement precision
If the switch system interrupts current flow to perform diagnosis, then the ability to detect switch state is improved, but the operational continuity is reduced
Solution Approach 1:
The diagnosis is performed by applying voltage to the gate terminals before any potential failure occurs, allowing the system to detect the on/off state of the switch without interrupting the main current flow. The diagnosis circuit operates independently and simultaneously with the power transmission function.
Solution Approach 2:
The patent introduces a dedicated diagnosis circuit as an intermediary system that can detect switch state without affecting the main power current. The diagnosis circuit uses separate voltage application paths that do not interfere with the primary current flow through the bidirectional switch.
Data Source
AI summary
A switch system includes a bidirectional switch, a first gate driver circuit, a second gate driver circuit, a control unit, a first decision unit, and a second decision unit. The bidirectional switch includes a first source, a second source, a first gate, and a second gate. The first decision unit determines, based on a voltage at the first gate and a first threshold voltage, a state of the first gate in a first period in which a signal to turn OFF the first gate is output from the control unit to the first gate driver circuit. The second decision unit determines, based on a voltage at the second gate and a second threshold voltage, a state of the second gate in a second period in which a signal to turn OFF the second gate is output from the control unit to the second gate driver circuit.