Bidirectional AC-DC Converter Topology With Shared Secondary ZVS Control
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Solution Overview
Problem
Conventional phase modular single-stage AC-DC power supplies have high component counts and costs due to the need for independent control of three individual phases, leading to increased complexity and inefficiency.
Innovation Solution
A bidirectional AC-DC power supply design that integrates multiple primary circuits, transformers, and a single secondary circuit, utilizing a control circuit to achieve zero-voltage-switching (ZVS) by controlling phase shifts of the switches, reducing the component count and ensuring efficient operation across varying load and voltage ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If phase modular single-stage AC-DC power supplies use independent control of three individual phases, then each phase can be controlled separately, but the component count and cost increase significantly
Solution Approach 1:
The patent combines three separate single-phase AC-DC power supplies into a single integrated three-phase power supply unit. The three primary circuits share a common secondary circuit, control circuit, and rectifier stage, merging previously separate components into a unified system that maintains independent phase control while reducing overall component count and cost.
Solution Approach 2:
The common secondary circuit and control circuit serve all three phases simultaneously, making these components universal rather than phase-specific. The single control circuit can independently regulate all three phases, and the shared rectifier stage processes output from all phases, achieving multi-functionality that reduces redundancy.
2Reliability
If conventional LLC converters use multiple secondary rectifier stages, then each phase can be rectified independently, but the component count and cost increase
Solution Approach 1:
The patent merges three separate secondary rectifier stages into a single common rectifier circuit that processes output from all three phases. This unified rectifier stage maintains the ability to independently rectify each phase while eliminating redundant components and reducing overall component count.
3Adaptability or versatility
If three-phase modular arrangement uses multiple LLC resonant tanks, then each phase can operate independently, but the component count and cost increase
Solution Approach 1:
The patent combines three separate LLC resonant tanks into a single integrated resonant tank system that supports all three phases. The unified resonant tank maintains phase independence through controlled switching while reducing the total number of magnetic components and overall system complexity.
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 proposed design significantly reduces component count and cost while maintaining ZVS for all switches, achieving efficient bidirectional voltage conversion with low harmonic distortion and high efficiency across a wide range of loads and voltages.
Implementation Method 1
The control circuit is configured to control switches of the plurality of primary circuits and the secondary circuit to switch under zero voltage by controlling phase shifts of the switches of the plurality of primary circuits
Implementation Method 2
A primary winding of each transformer is coupled to a corresponding one of the plurality of primary circuits, and a plurality of secondary windings of the plurality of transformers are electrically connected in series
Data Source
AI summary
A bidirectional AC-DC power supply is provided. The bidirectional AC-DC power supply includes a plurality of primary circuits, a plurality of transformers, one secondary circuit and a control circuit. The plurality of primary circuits are electrically connected to a plurality of phase voltages of an AC power respectively. The plurality of transformers are electrically connected to the plurality of primary circuits respectively. A primary winding of each transformer is coupled to a corresponding one of the plurality of primary circuits, and a plurality of secondary windings of the plurality of transformers are electrically connected in series. The secondary circuit is electrically connected to the plurality of secondary windings of the plurality of transformers. The control circuit is configured to control switches of the plurality of primary circuits and the secondary circuit to switch under zero voltage by controlling phase shifts of the switches of the plurality of primary circuits.