Two-Stage Power Converter With Switched-Capacitor Voltage Inversion
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Solution Overview
Problem
Existing power converters struggle to efficiently convert varying input voltages, such as those encountered in next-generation communication services, into stable output voltages while maintaining high power density and efficiency.
Innovation Solution
The proposed solution involves a two-stage power converter system, where a first stage converts an input voltage into an intermediate negative voltage, and a second stage, a transformer-less switched-capacitor converter, inverts this intermediate voltage to produce a positive output voltage, achieving efficient voltage inversion and regulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a conventional switching power converter is used to convert varying input voltages, then voltage conversion is achieved, but efficiency and power density are reduced
Solution Approach 1:
The power converter is divided into multiple stages: a first stage (buck converter) that converts input voltage to an intermediate negative voltage, and a second stage (transformer-less switched-capacitor converter) that inverts the intermediate voltage to produce the final positive output voltage. This segmentation allows each stage to operate optimally, achieving high efficiency while maintaining high power density through the transformer-less design.
2Adaptability or versatility
If input voltage varies between -35V to -75V with spikes up to -100V, then adaptability is improved, but stability of output voltage deteriorates
Solution Approach 1:
The controller associated with the buck converter compares the magnitude of the generated output voltage to a setpoint reference voltage and modifies switching frequency and pulse width modulation based on the error voltage. This feedback mechanism ensures stable output voltage despite wide variations in input voltage including spikes up to -100V.
Solution Approach 2:
The system dynamically adjusts switching frequency and pulse width modulation in response to input voltage variations. The controller modifies these parameters in real-time to maintain stable output voltage across the wide input range from -35V to -75V with spikes up to -100V.
3Productivity
If high power density is achieved, then productivity is improved, but device complexity increases
Solution Approach 1:
The transformer is extracted/removed from the conventional power converter design. The second stage uses a transformer-less switched-capacitor converter topology that achieves voltage inversion without requiring a transformer, thereby reducing device complexity while maintaining high power density.
4Device complexity
If transformer-less switched-capacitor converter is used, then device complexity is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The switched-capacitor converter uses periodic switching of capacitors to achieve voltage inversion. The controller implements regular switching cycles with precise timing control, where capacitors are charged and discharged in a periodic manner to transfer energy and convert voltage without requiring a transformer.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach results in high efficiency, high power density, and flat efficiency curves over a wide load range, with lower voltage ratings for semiconductor devices, enabling effective use of green energy sources and reducing environmental impact.
Implementation Method 1
a switched-capacitor-converter is configured to receive the intermediate voltage and provide an output voltage for supplying a load
Data Source
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AI summary
This disclosure includes novel ways of implementing a power supply that powers a load. More specifically, a power supply includes a controller. The controller controls operation of a first power converter stage and a second power converter stage to convert an input voltage into an output voltage. For example, the first power converter stage is operative to receive an input voltage and convert the input voltage into an intermediate voltage. The second power converter stage such as a transformer-less switched-capacitor converter is coupled to the first power converter stage. The second power converter stage receives the intermediate voltage and converts the intermediate voltage into an output voltage to power a load.