Single Switching Stage Power Control for High Power Factor
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Solution Overview
Problem
Conventional DC-DC converters have less than unity power factor due to their switching nature, leading to inefficient power transfer from AC power sources and potential stress on AC line voltages, and require complex feedback loops for control, which can result in instability.
Innovation Solution
A single switching stage power control apparatus that achieves high power factor without monitoring load voltage or current, using a feed-forward control method to modulate power delivery based on known load requirements, eliminating the need for feedback loops and simplifying circuitry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If conventional DC-DC converters use switching operation to regulate output voltage, then voltage regulation is achieved, but power factor deteriorates (less than unity)
Solution Approach 1:
The patent combines power factor correction and voltage regulation into a single integrated circuit stage, eliminating the need for separate PFC and DC-DC converter stages. This merging approach achieves both unity power factor and regulated output voltage simultaneously, resolving the contradiction between voltage regulation and power factor maintenance.
Solution Approach 2:
The single switching stage performs multiple functions: it corrects power factor, regulates output voltage, and provides protective isolation. This multi-functional design eliminates the need for separate dedicated circuits for each function, achieving high power factor while maintaining voltage regulation capability.
2Stability of the object's composition
If conventional DC-DC converters implement feedback control loops for voltage regulation, then output stability is improved, but circuit complexity increases
Solution Approach 1:
The circuit uses the load's own current characteristics to automatically control the switching duty cycle without requiring external feedback sensors or complex control loops. The load current itself serves as the control signal, simplifying the circuit while maintaining stability through the inherent relationship between input voltage, output voltage, and duty cycle.
Solution Approach 2:
The patent implements a simplified feedback mechanism where the load current directly influences the switching control. This inherent feedback approach eliminates complex voltage sensing and regulation circuits while maintaining output stability through the natural coupling between stages.
3Use of energy by moving object
If conventional power supplies use separate PFC stage and DC-DC converter stage, then power factor correction and voltage regulation are achieved, but component redundancy increases
Solution Approach 1:
The patent merges the PFC stage and DC-DC converter stage into a single integrated circuit with one switching element. This consolidation eliminates redundant components and stages while achieving both unity power factor and regulated output voltage, directly addressing the contradiction between power factor correction and component redundancy.
Solution Approach 2:
The single switching stage is designed to perform multiple functions simultaneously: power factor correction, voltage regulation, and protective isolation. This universal design eliminates the need for separate dedicated circuits for each function, reducing component count while maintaining all required performance characteristics.
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 improves power efficiency, reduces component redundancy, and stabilizes power transfer, achieving high power factor and streamlined circuit designs with fewer components and smaller size.
Implementation Method 1
the transistor switch 20 is operated to periodically apply the unregulated DC input voltage 30 (V in ) across an inductor 22 (L) for relatively short time intervals... During the intervals in which the transistor switch is 'on' or closed (i.e., passing the input voltage V in to the inductor), current flows through the inductor based on the applied voltage and the inductor stores energy in its magnetic field
Implementation Method 2
When the switch is turned 'off' or opened (i.e., the DC input voltage is removed from the inductor), the energy stored in the inductor is transferred to a filter capacitor 34 which functions to provide a relatively smooth DC output voltage V out to the load 40
Data Source
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AI summary
Methods and apparatus for high power factor power transfer to a load using a single switching stage. In exemplary implementations, a controllable variable power may be delivered to a load using a single switching stage while maintaining high power factor, in some cases without requiring any feedback information relating to the load conditions (i.e., without monitoring load voltage and/or current) to control normal switching operations in the single switching stage, and without requiring regulation of load voltage and/or load current. In one example, a single stage high power factor driver is used to control power delivery to an LED-based light source.