Flyback Active Clamping Power Converter Resonant Frequency
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Solution Overview
Problem
Traditional flyback converters suffer from high spike voltages in the secondary side diode, limiting efficiency and increasing switching losses due to electromagnetic interference and voltage spikes caused by leakage inductance.
Innovation Solution
A flyback active clamping power converter is designed with a resonant frequency equal to the switching frequency, utilizing an input inductor, down-bridge and up-bridge switches, energy-storing capacitors, a resonant inductor, magnetizing inductor, transformer, and output diode, allowing zero current switching and reducing switching losses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If traditional flyback converter topology is used, then circuit structure is simple, but spike voltage and switching losses increase due to leakage inductance
Solution Approach 1:
The patent introduces a resonant inductor and clamping capacitor as intermediary components that form a resonant circuit between the primary winding and leakage inductance. This resonant circuit acts as a mediator to transfer energy smoothly during switching transitions, eliminating voltage spikes and reducing switching losses without significantly complicating the overall circuit structure.
Solution Approach 2:
The patent changes the operating parameters by tuning the resonant frequency of the added LC circuit to match the switching frequency. This parameter adjustment transforms the harmful leakage inductance into a useful resonant element, enabling zero-current switching and eliminating reverse-recovery current while maintaining circuit simplicity.
2Loss of energy
If traditional flyback converter is used, then conversion efficiency is limited, but output power can be maintained
Solution Approach 1:
The patent achieves continuous energy transfer by creating a resonant oscillation between the primary winding and the resonant inductor-clamping capacitor circuit. This continuous resonant action eliminates the discontinuous energy transfer inherent in traditional flyback converters, maintaining output power while dramatically improving conversion efficiency to approximately 91.47%.
Solution Approach 2:
The patent converts the harmful leakage inductance and reverse-recovery current into beneficial resonant energy transfer. By introducing the clamping capacitor and resonant inductor, the previously wasted energy in voltage spikes and reverse-recovery current is transformed into useful resonant oscillation that improves efficiency while maintaining output power.
3Volume of moving object
If higher frequency operation is implemented, then circuit volume is reduced, but switching losses increase
Solution Approach 1:
The patent applies the principle of mechanical vibration by creating an electrical resonant oscillation at the switching frequency. This resonant vibration enables the circuit to operate efficiently at high frequencies without excessive switching losses, as the energy transfer occurs through smooth oscillatory motion rather than abrupt switching transitions.
Solution Approach 2:
The patent implements periodic resonant oscillation between the primary winding and the resonant circuit components. This periodic action synchronizes with the switching frequency, allowing the circuit to maintain low losses at high operating frequencies while reducing the size of magnetic components and overall circuit volume.
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
The solution enhances power conversion efficiency by eliminating reverse-recovery current and spike voltage on the output diode, enabling the use of lower peak inverse voltage diodes and reducing circuit volume through high-frequency operation, achieving a conversion efficiency of about 91.47%.
Implementation Method 1
when the resonant frequency generated by the resonant inductor and the clamping capacitor in the flyback active clamping power converter is substantially equal to the switching frequency
Implementation Method 2
The transformer has a primary winding and a secondary winding, and the primary winding is connected with the magnetizing inductor in parallel, wherein there is a mutual inductance effect between the primary winding and the secondary winding
Data Source
AI summary
A flyback active clamping power converter is disclosed. The flyback active clamping power converter comprises an input inductor, a down-bridge switch, an up-bridge switch, a first energy-storing capacitor, a clamping capacitor, a resonant inductor, a magnetizing inductor, a transformer, an output diode and an output capacitor. When a resonant frequency generated by the resonant inductor and the clamping capacitor in the flyback active clamping power converter is substantially equal to a switching frequency, the output diode is able to perform a zero current switching in the whole load range.