Power Module Diagnosis Circuit for Rapid Failure Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In three-phase-six-arm power modules, failures such as short circuits can lead to large currents damaging the module and causing abnormal output, with prolonged diagnosis times risking secondary damage to the system.
Innovation Solution
A diagnosis circuit and method that utilize feedback signals of gate voltages, drain-source voltages, and phase currents to rapidly detect module failures, incorporating logic circuits, filter circuits to remove noise, and latches to store diagnosis signals, allowing for quick identification and prevention of secondary damage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the diagnosis time is extended to ensure accurate detection of power module failures, then the measurement precision is improved, but the power module is exposed to prolonged harmful currents that cause secondary damage
Solution Approach 1:
The diagnosis circuit performs preliminary detection of power module failures by continuously monitoring arm voltages and phase currents. The logic circuit compares voltages of corresponding arms in real-time to identify failures before they cause extensive secondary damage, enabling early protective action.
Solution Approach 2:
The diagnosis circuit rapidly detects failures by directly comparing arm voltages through the logic circuit without extensive processing delays. The filter circuit removes transient noises quickly, and the latch circuit immediately latches the diagnosis result, enabling the system to rush through the detection process and minimize exposure time to harmful currents.
2Reliability
If the diagnosis circuit continuously monitors all arm voltages and phase currents to ensure reliable failure detection, then the reliability is improved, but the device complexity increases due to additional logic circuits, filter circuits, and latch circuits
Solution Approach 1:
The diagnosis circuit is segmented into three functional modules: a logic circuit for voltage comparison and failure determination, a filter circuit for noise removal, and a latch circuit for result storage. This segmentation allows each module to perform its specific function efficiently while maintaining overall system reliability.
Solution Approach 2:
The logic circuit performs multiple functions: it receives arm voltage signals, compares voltages of corresponding arms, determines failure conditions, and generates diagnosis results. The filter circuit simultaneously handles transient noise filtering for multiple signal channels, reducing the need for separate filtering components for each signal.
3Ease of manufacture
If the diagnosis circuit uses simple comparison methods to reduce device complexity, then the ease of manufacture is improved, but the measurement precision of failure detection deteriorates due to transient noises and signal interference
Solution Approach 1:
The filter circuit acts as an intermediary between the logic circuit and the input signals. It removes transient noises and signal interference before the signals reach the logic circuit for comparison, ensuring accurate failure detection without complicating the overall circuit design. The latch circuit serves as an intermediary that stabilizes the diagnosis result before it is used for protective actions.
Data Source
AI summary
A diagnosis circuit comprises: a logic circuit, wherein the logic circuit comprises a set having a gate voltage terminal of an arm of a phase logical OR a dead time voltage terminal, and the set logical XOR a drain-source voltage terminal of another arm of the phase; a filter circuit coupled to the logic circuit, wherein the filter circuit is configured to filter transient noises; a comparison circuit coupled to the filter circuit, wherein the comparison circuit is configured to determine whether a phase current of a phase current terminal of the phase is greater than zero; and a latch coupled to the comparison circuit, wherein the latch is configured to store diagnosis signals temporarily.