Half-Bridge AC-DC Power Supply With Phase-Shifted Transformer Control
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Solution Overview
Problem
Existing power supply devices from alternating voltage suffer from high heat generation and low conversion efficiency, making them less compact and less efficient compared to the proposed solution.
Innovation Solution
The power supply device incorporates a capacitive element, half-bridge switches, a transformer, and a full-wave rectifier circuit, with control circuits to manage chopping frequency and phase shift, utilizing HEMT transistors for efficient energy conversion and zero-voltage switching to minimize heat and maximize efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional power supply devices are used to convert AC voltage to DC voltage, then power supply function is achieved, but heat generation is high and conversion efficiency is low
Solution Approach 1:
The patent employs periodic switching of electronic switches (transistors) at high frequency to control the flow of current through the transformer windings. This periodic action enables pulse-width modulation (PWM) control, where the duty cycle of the switching waveform is adjusted to regulate output voltage while minimizing energy losses. The periodic switching allows the system to operate in discontinuous conduction mode, reducing core losses and improving overall conversion efficiency.
Solution Approach 2:
The patent utilizes variable switching frequency and adjustable duty cycle as control parameters to optimize conversion efficiency across different operating conditions. By dynamically changing the switching frequency and pulse width, the controller adapts to varying load conditions and input voltage levels, maintaining peak efficiency. The system also adjusts the phase difference between primary and secondary side switching waveforms to minimize overlapping currents and reduce copper losses.
2Volume of moving object
If conventional power supply devices are used, then power conversion is achieved, but the device size is large and not compact
Solution Approach 1:
The patent employs a single transformer that performs multiple functions: voltage transformation, galvanic isolation, and energy storage. The coupled inductors on both primary and secondary sides serve dual purposes as both transformers and energy storage elements, eliminating the need for separate inductors. This multi-functionality significantly reduces the number of magnetic components and overall device volume while maintaining full power conversion capability.
Solution Approach 2:
The patent utilizes high-frequency switching operation (typically 50-200 kHz) compared to conventional line-frequency operation. This dynamic switching enables the use of smaller magnetic components since the required inductance values are inversely proportional to switching frequency. The system dynamically adjusts switching parameters to maintain stable operation across varying conditions, allowing compact component design without sacrificing power conversion performance.
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 results in a more compact and efficient power supply device that operates with reduced heat generation and higher conversion efficiency, capable of delivering DC voltage from AC sources with improved energy management.
Implementation Method 1
a transformer, comprising a first winding placed between one of the input terminals and a connection node between the first switches
Implementation Method 2
a first capacitive element; two second capacitive elements electrically in series between the output terminals
Implementation Method 3
utilizing HEMT transistors for efficient energy conversion and zero-voltage switching
Data Source
AI summary
The present description relates to a device for supplying a voltage from an AC voltage, comprising: - a capacitive element (120); - two switches (132H, 132L) in a half-bridge configuration between terminals of the capacitive element (120); - terminals (102, 104) for applying the AC voltage; - a transformer (160), comprising a first winding (162) connecting one of the terminals (104) for applying the AC voltage to a link node (136) between the switches (132H, 132L); and - one or more circuits (170, 180, 140) configured so as to: switch the switches (132H, 132L) and receive an AC current (I164) flowing in a second winding (164) of the transformer (160); and adjust the voltage provided by the device by acting on a frequency of said AC current and/or on a phase offset of said AC current with respect to when it is received.