Cut-off Switch Protection Circuit for Rapid Overvoltage Isolation
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Solution Overview
Problem
Conventional overvoltage protection methods in power systems, such as those used in automotive safety applications, are slow to detect overvoltage conditions, which can lead to damage to electronic devices due to the delayed isolation from high voltage.
Innovation Solution
A protection circuit with a cut-off switch is implemented between a power source and a power converter, utilizing a controller to generate a driving signal and detect fault conditions by monitoring current through the cut-off switch, isolating the power source when an electrical short is detected, thereby preventing overvoltage damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional overvoltage protection methods are used, then the protection system is simple to implement, but the detection speed is slow (tens of microseconds) causing delayed isolation from high voltage
Solution Approach 1:
The patent implements preliminary action by performing fault detection before damage occurs. The controller continuously monitors the state of power switches and detects overvoltage conditions in real-time, enabling protection to be activated before the high voltage can damage connected electronic devices. This is achieved through proactive monitoring of switch states and voltage levels rather than reactive response after damage begins.
Solution Approach 2:
The patent employs feedback mechanisms where the controller receives status information from the power converter (including switch states and current levels) and uses this feedback to detect fault conditions. The controller compares actual system state against expected operational parameters and triggers protection when deviations indicate overvoltage or short circuit conditions, enabling rapid response based on continuous system monitoring.
2Reliability
If a cut-off switch is added for rapid isolation, then the protection speed improves (within one clock cycle), but the device complexity increases
Solution Approach 1:
The patent introduces a cut-off switch as an intermediary component between the power source and the power converter. This intermediary element acts as a physical barrier that can be rapidly activated to isolate the load from the power source when faults are detected. The cut-off switch serves as a mediator that breaks the electrical connection within one clock cycle of detecting overvoltage or short circuit conditions, preventing damage to connected devices while adding minimal complexity to the overall system.
3Measurement precision
If continuous monitoring of current and gate control signals is performed, then fault detection precision improves, but the energy consumption increases
Solution Approach 1:
The patent implements continuous monitoring of current flow and gate control signals to maintain precise fault detection capability throughout operation. The controller continuously compares actual current levels against expected values and monitors gate signal states to detect abnormalities. This continuous action ensures that overvoltage and short circuit conditions are detected immediately when they occur, maintaining high measurement precision while managing energy consumption through efficient monitoring algorithms.
Data Source
AI summary
A method of operating a power protection system coupled between a power source and a power converter includes producing, by a controller of the power protection system, a driving signal to a cut-off switch of the power protection system to electrically couple the power source to the power converter; detecting, by the controller of the power protection system, a fault condition of the power converter while the power converter is in operation, where the detecting includes detecting, by the controller of the power protection system, that a current flowing through the cut-off switch is above a pre-determined threshold while a gate control signal from the power converter indicates an OFF state for a first current path of the power converter; and in response to detecting the fault condition, turning off, by the controller of the power protection system, the cut-off switch to isolate the power source from the power converter.