Single-Stage Resonant Converter Without Intermediate Energy Storage
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Solution Overview
Problem
Traditional AC-to-DC converters have a two-stage circuit structure that includes an intermediate energy storage component, leading to large size and hindering miniaturization, especially in three-phase converters.
Innovation Solution
A single-stage AC-to-DC resonant converter with a primary-side circuit, resonant circuit, and secondary-side circuit, utilizing multiple switches for direct conversion without intermediate energy storage, and incorporating transformers with common windings to reduce components and size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a two-stage circuit structure with intermediate energy storage component is used, then power conversion reliability is improved, but device size becomes large and miniaturization is hindered
Solution Approach 1:
The patent combines the AC-to-DC conversion and DC-to-DC conversion functions into a single integrated circuit stage. The primary-side switch circuit performs both rectification and power factor correction, while the resonant tank circuit enables direct coupling between AC input and DC output without requiring separate intermediate energy storage stages, thereby reducing overall device volume while maintaining conversion reliability
Solution Approach 2:
The patent extracts and eliminates the intermediate energy storage component (intermediate capacitor) from the traditional two-stage architecture. By using the resonant tank circuit with transformers and switching devices, the system achieves direct AC-to-DC conversion without the bulky intermediate capacitor, removing the source of volume expansion while preserving power conversion functionality
2Reliability
If three AC-to-DC conversion circuits are used for three-phase power source, then complete power conversion is achieved, but device size becomes excessively large
Solution Approach 1:
The patent implements a universal single-stage conversion circuit that can handle three-phase AC power sources. The primary-side switch circuit is designed with multiple switching devices that can process all three phases simultaneously through a unified resonant tank circuit, eliminating the need for three separate conversion circuits and their associated intermediate capacitors, thus achieving complete power conversion with significantly reduced size
Solution Approach 2:
The patent merges the three separate AC-to-DC conversion circuits into a single integrated circuit. The resonant tank circuit combines the processing of all three phases through shared transformers and switching devices, with the secondary-side circuit consolidating the output from all phases into a single DC output, thereby achieving three-phase power conversion without requiring three times the conventional component count
3Quantity of substance
If intermediate capacitor is used to store large amount of power, then power storage capability is improved, but configuration space requirement increases
Solution Approach 1:
The patent replaces the traditional intermediate capacitor (passive energy storage component) with an active resonant tank circuit consisting of transformers and switching devices. This substitution enables power transfer and temporary energy storage through electromagnetic induction and resonant oscillation, achieving equivalent or superior power storage capability without the large physical footprint of a high-capacity intermediate capacitor
Solution Approach 2:
The patent changes the operating parameters of the power conversion system by using resonant frequency operation. The resonant tank circuit operates at specific resonant frequencies determined by the inductance and capacitance values, enabling efficient energy transfer and storage through resonant oscillation. This parameter-based approach allows compact component values to achieve the required power storage capability, dramatically reducing configuration space compared to conventional capacitor-based storage
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 single-stage converter achieves efficient power conversion with reduced component count and size, eliminating the need for intermediate energy storage, thereby facilitating miniaturization and improving power factor correction and efficiency.
Implementation Method 1
resonant circuit includes three transformers, primary-side windings of the transformers are respectively coupled the switching circuits of the primary-side switch circuits
Implementation Method 2
secondary-side windings of the transformers form a secondary-side common winding
Data Source
AI summary
A single-stage AC-to-DC resonant converter is used to convert a three-phase AC power source into a DC power source. The single-stage AC-to-DC resonant converter includes a primary-side circuit, a resonant circuit, and a secondary-side circuit. The primary-side circuit includes three primary-side switch circuits, and each primary-side switch circuit is coupled to one phase of the three-phase AC power source. The resonant circuit includes three transformers, and primary-side windings of the transformers are respectively coupled to the primary-side switch circuits, and secondary-side windings of the transformers are coupled to the secondary-side circuit.