Switched Capacitor Converter Short-Circuit Detection Coverage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing short circuit detection tests for switched capacitor converters only cover short circuits across the flying capacitor and do not adequately test all switching elements, which is a safety and reliability concern due to the ultra-low resistance of power switches.
Innovation Solution
A method and apparatus for comprehensive short circuit detection in switched capacitor converters, involving a four-step process that compares voltages across different switches and the flying capacitor using dedicated circuits and control switches to determine if any of these components are shorted, ensuring thorough testing of all switching elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing short circuit detection tests are used, then the flying capacitor short circuit is detected, but other switching elements are not adequately tested
Solution Approach 1:
The detection process is divided into multiple sequential steps, each targeting specific switching elements. The first step detects short circuits in the first and third switches by monitoring voltage at their common node, while the second step detects short circuits in the second and fourth switches through different voltage comparison circuits. This segmentation allows comprehensive coverage without requiring a single complex detection mechanism.
Solution Approach 2:
The detection apparatus performs preliminary voltage comparisons before full operation to identify potential short circuits. By checking voltage conditions at specific nodes against reference voltages before the converter enters normal switching operation, the system can detect short circuits in all switching elements proactively, preventing damage before it occurs.
2Reliability
If comprehensive short circuit detection for all switching elements is implemented, then reliability is improved, but detection complexity increases
Solution Approach 1:
The patent introduces intermediary voltage comparison circuits that simplify the detection process. Instead of directly measuring complex current conditions or using multiple sensors, the invention uses voltage dividers and comparison circuits that convert short circuit detection into simple voltage threshold comparisons. These intermediary circuits make the detection method easier to implement while maintaining comprehensive coverage of all switching elements.
Solution Approach 2:
The detection apparatus uses reference voltage copies and mirrored circuit configurations to simplify measurement. By creating reference voltage levels that represent expected normal operation conditions and comparing actual node voltages against these references, the system can detect deviations indicating short circuits without requiring direct measurement of complex operating parameters.
Data Source
AI summary
A method includes connecting an input voltage bus of a switched capacitor converter to a power source through a load switch, in a first short circuit testing step, determining whether the load switch or a second switch is shorted by comparing a voltage on the input voltage bus with a first predetermined voltage reference, after passing the first short circuit testing step, in a second short circuit testing step, determining whether a first switch or a fourth switch is shorted by comparing a voltage on the common node of the third switch and the fourth switch with a second predetermined voltage reference, and after passing the second short circuit testing step, in a third short circuit testing step, determining whether a third switch is shorted by comparing the voltage on the common node of the third switch and the fourth switch with a third predetermined voltage reference.