Half-Bridge Converter Rectifier Structure Using Coupling Inductor
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Solution Overview
Problem
Asymmetrical half-bridge converters designed for wide input voltage ranges experience high DC offset currents, leading to increased transformer size, cost, and reduced efficiency, as well as poor zero-voltage switching due to asymmetric primary-side switch operation.
Innovation Solution
The proposed asymmetrical half-bridge converter employs a new rectifier structure using coupling inductors to eliminate DC offset currents, featuring a primary-side circuit with switches, capacitors, and magnetization inductors, and a secondary-side circuit with diodes and rectification inductors, which sets the average current flowing into capacitors to zero, reducing transformer size and improving zero-voltage switching efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the asymmetrical half-bridge converter is designed for wide input voltage range, then the input voltage adaptability is improved, but high DC offset current is generated in the transformer
Solution Approach 1:
The patent extracts the DC offset current from the transformer by introducing a dedicated offset current path through the coupling inductor. The coupling inductor is connected in parallel with the transformer secondary winding, providing a separate path for DC offset current to circulate without passing through the transformer, thereby eliminating the harmful DC offset effect while maintaining wide input voltage range operation.
Solution Approach 2:
The coupling inductor acts as an intermediary element that mediates between the transformer and the output circuit. It transfers the offset current away from the transformer while allowing the main power transfer function to continue uninterrupted. This intermediary structure enables the transformer to operate without DC offset accumulation even when operating across wide input voltage ranges.
2Adaptability or versatility
If the asymmetrical half-bridge converter is designed for wide input voltage range, then the input voltage adaptability is improved, but the transformer size increases
Solution Approach 1:
By extracting the DC offset current path from the transformer through the coupling inductor, the transformer no longer needs to be oversized to handle DC offset accumulation. This allows the transformer to be sized appropriately for its actual power transfer function, reducing its volume while maintaining wide input voltage range capability.
Solution Approach 2:
The coupling inductor serves as an intermediary that absorbs the DC offset current handling function, allowing the transformer to be optimized for its core power transfer role. This separation of functions enables the transformer to be smaller since it doesn't need to accommodate DC offset effects in its design.
3Adaptability or versatility
If the asymmetrical half-bridge converter is designed for wide input voltage range, then the input voltage adaptability is improved, but the efficiency decreases
Solution Approach 1:
By extracting the DC offset current through the coupling inductor path, the patent eliminates energy losses associated with DC offset in the transformer. The coupling inductor has low DC resistance and provides an efficient path for offset current, preventing energy waste while maintaining wide input voltage operation.
Solution Approach 2:
The coupling inductor acts as an efficient intermediary that redirects DC offset current away from the transformer, preventing energy losses in the transformer core and windings. This intermediary path maintains high conversion efficiency across the wide input voltage range by eliminating parasitic losses.
4Adaptability or versatility
If the asymmetrical half-bridge converter is designed for wide input voltage range, then the input voltage adaptability is improved, but the zero-voltage switching performance deteriorates
Solution Approach 1:
By extracting the DC offset current path from the main circuit through the coupling inductor, the patent restores the zero-voltage switching capability. The removal of DC offset current allows the resonant current to properly charge and discharge the output capacitance of the switches, enabling reliable zero-voltage switching across the wide input voltage range.
Solution Approach 2:
The coupling inductor acts as an intermediary that removes the harmful DC offset effect while preserving the AC resonant current path needed for zero-voltage switching. This intermediary structure allows the resonant current to flow freely for soft switching while the coupling inductor handles the DC offset separately, maintaining both wide voltage range operation and reliable zero-voltage switching.
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 configuration allows for high-efficiency operation across a wide input voltage range, reducing the converter's size, enhancing zero-voltage switching, and achieving improved voltage gain and reduced conduction losses, thereby improving overall efficiency and cost-effectiveness.
Implementation Method 1
a first coupling inductor having one end connected to the cathode of the first diode and having the other end connected to the first capacitor, and a second coupling inductor having one end connected to the anode of the second diode and having the other end connected to the second capacitor
Data Source
AI summary
Disclosed is an asymmetrical half-bridge converter having high efficiency in a wide input voltage range. The converter may include a primary-side circuit including a first switch, a second switch, a primary-side capacitor, an additional inductor, and a primary-side magnetization inductor, and a secondary-side circuit including first and second diodes connected in series, first and second capacitors connected in series, a secondary-side rectification inductor having one end connected to the anode of the first diode and cathode of the second diode, and having the other end connected between the first and second capacitors connected in series, a first coupling inductor having one end connected to the cathode of the first diode and having the other end connected to the first capacitor, and a second coupling inductor having one end connected to the anode of the second diode and having the other end connected to the second capacitor.