Switched-Capacitor Power Converter for Inrush Current Blocking
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Solution Overview
Problem
Conventional power converters face inefficiencies and safety risks due to current rushes and heat generation when converting wide input voltage ranges, particularly when the duty ratio exceeds 50%, which is not adequately addressed by existing switch capacitor buck circuit topologies.
Innovation Solution
A power converter design that includes controlled input switches and parallel bridge arms with synchronized switch operation to mitigate current rushes, coupled with a precharge circuit to prevent initial voltage imbalances and clamping circuits to manage switch voltages, enhancing efficiency and safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the duty ratio is increased to maintain stable output when input voltage is lower than 48V, then the output voltage stability is improved, but current rush between capacitors increases causing efficiency reduction and heat generation
Solution Approach 1:
The patent introduces an intermediary control mechanism that monitors the duty ratio and prevents it from exceeding 50%. When the duty ratio approaches 50%, the system switches to an alternative operating mode or adjusts the switching sequence to avoid direct capacitor connections that cause current rush. This intermediary control resolves the contradiction by maintaining output stability through alternative means while preventing the harmful current rush that reduces efficiency.
Solution Approach 2:
The patent dynamically adjusts the switching sequence and duty ratio based on the input voltage level. When input voltage is below 48V, instead of simply increasing the duty ratio, the system dynamically changes the switching pattern to avoid direct capacitor connections. This dynamic adaptation allows the system to maintain output stability while preventing current rush and efficiency loss.
2Stability of the object's composition
If the duty ratio is increased to maintain stable output when input voltage is lower than 48V, then the output voltage stability is improved, but heat energy generation increases causing safety risks
Solution Approach 1:
The patent introduces an intermediary control mechanism that monitors the duty ratio and prevents it from exceeding 50%. When the duty ratio approaches 50%, the system switches to an alternative operating mode or adjusts the switching sequence to avoid direct capacitor connections that cause current rush. This intermediary control resolves the contradiction by maintaining output stability through alternative means while preventing the harmful current rush that reduces efficiency.
Solution Approach 2:
The patent dynamically adjusts the switching sequence and duty ratio based on the input voltage level. When input voltage is below 48V, instead of simply increasing the duty ratio, the system dynamically changes the switching pattern to avoid direct capacitor connections. This dynamic adaptation allows the system to maintain output stability while preventing current rush and efficiency loss.
3Power
If a bus voltage converter is added to convert 54V to 12V, then the power bus voltage conversion is achieved, but conversion losses increase reducing overall efficiency
Solution Approach 1:
The patent employs a self-service approach where the power converter circuit is designed to minimize its own losses through optimized switching sequences and capacitor management. By preventing current rush between capacitors and optimizing the duty ratio operation, the circuit reduces its inherent conversion losses without requiring additional active compensation circuits, thereby improving overall efficiency while maintaining the 54V to 12V conversion capability.
Data Source
AI summary
The present disclosure provides a power converter including an input capacitor, an input switch, first and second bridge arms, first and second storage capacitors and an output capacitor. The first and second bridge arms are connected in parallel between a second terminal of the input switch and the ground terminal. The first bridge arm includes three switches connected in series and has first upper and lower nodes therebetween. The second bridge arm includes three switches connected in series and has second upper and lower nodes therebetween. The first storage capacitor is coupled between the first upper node and the second lower node. The second storage capacitor is coupled between the second upper node and the first lower node. The input switch is configured to block a rush current between the input capacitor and the first storage capacitor and/or the second storage capacitor.