Series Switch Power Supply Cutoff Fault Detection by Voltage Comparison
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Solution Overview
Problem
Existing power supply devices with semiconductor switches and mechanical switches in series face challenges in accurately detecting cutoff abnormalities due to similar terminal-to-terminal voltages between normal and abnormal semiconductor switches, leading to potential overvoltage issues.
Innovation Solution
A power supply device with voltage detectors and a control system that compares terminal-to-terminal voltages of semiconductor switches, using a determination unit to identify mismatches and detect cutoff abnormalities, ensuring accurate detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If both the mechanical switch and the switch circuit are turned off, then the voltage difference is applied to the mechanical switch due to its higher off resistance, but the terminal-to-terminal voltage of semiconductor switches becomes close to zero and cannot significantly differ from abnormal switches
Solution Approach 1:
The patent applies preliminary action by turning on the mechanical switch before detecting semiconductor switch abnormalities. This creates a voltage distribution state where semiconductor switches that are turned off exhibit detectable voltage differences relative to each other, enabling accurate abnormality detection before the mechanical switch is turned off and voltage distribution changes.
Solution Approach 2:
The patent employs dynamics by changing the operational state of the mechanical switch based on detection timing. The mechanical switch is turned on during abnormality detection to create favorable voltage distribution conditions, and turned off during normal power supply. This dynamic state change enables accurate voltage-based detection while maintaining system functionality.
2Device complexity
If the terminal-to-terminal voltage of semiconductor switches is used for detection, then the detection method is simple, but erroneous detection occurs when the voltage is close to zero
Solution Approach 1:
The patent applies dynamics by dynamically changing the state of the mechanical switch based on detection timing. The mechanical switch is turned on during abnormality detection to create favorable voltage distribution conditions, and turned off during normal power supply. This dynamic state change enables accurate voltage-based detection while maintaining system functionality.
Solution Approach 2:
The patent employs feedback by using voltage detection results to control the mechanical switch state and generate abnormality determination signals. The detection system continuously monitors terminal-to-terminal voltages and provides feedback to the control device, which adjusts the mechanical switch state and generates appropriate abnormality signals based on the detected voltage patterns.
Data Source
AI summary
A plurality of semiconductor switches and a mechanical switch are connected in series between a first terminal and a second terminal. A plurality of voltage detectors are provided corresponding to the plurality of semiconductor switches, respectively, and detect terminal-to-terminal voltages of the corresponding semiconductor switches. A plurality of drivers are provided corresponding to the plurality of semiconductor switches, respectively, and turn off the corresponding semiconductor switches in response to control signals from a main controller. Each driver determines whether or not a terminal-to-terminal voltage of the corresponding semiconductor switch matches a terminal-to-terminal voltage of another semiconductor switch of the plurality of semiconductor switches, and outputs a result of determination. The main controller detects a cutoff abnormality in which the plurality of semiconductor switches are not turned off normally, based on the result of determination provided from each of the plurality of drivers.