Universal PFC Converter with Four Half-Bridge Legs
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Solution Overview
Problem
Existing power-factor corrected AC/DC converters face challenges in efficiently handling both single-phase and three-phase AC inputs, particularly in achieving a stable 400 VDC output across varying AC mains voltages, which affects their efficiency and versatility in applications like battery chargers and data centers.
Innovation Solution
A truly universal PFC converter design that incorporates four half-bridge totem pole switching legs, passive components, and relays to operate in three modes: single-phase three-channel interleaved totem pole boost, three-phase boost, and cascaded three-phase boost followed by buck, allowing for bidirectional power flow and adaptive intermediate bus voltage control to maximize efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a converter is designed to handle both single-phase and three-phase AC inputs, then versatility is improved, but device complexity increases
Solution Approach 1:
The patent implements a universal converter design where the same hardware architecture can operate in multiple modes (single-phase and three-phase) by reconfiguring the switching legs. The converter uses four half-bridge totem pole switching legs that can be arranged in different configurations to accommodate both single-phase and three-phase AC inputs, eliminating the need for separate dedicated converters for each phase type.
Solution Approach 2:
The converter is divided into modular half-bridge totem pole switching legs that can be independently controlled and reconfigured. Each switching leg can operate autonomously or in combination with others, allowing the system to adapt its topology based on whether single-phase or three-phase input is detected, thereby managing complexity through modular segmentation.
2Loss of energy
If the converter operates in multiple modes with adaptive intermediate bus voltage, then efficiency is improved, but control complexity increases
Solution Approach 1:
The converter employs dynamic operating modes where the intermediate bus voltage is adaptively adjusted based on the input phase type and load conditions. The system can switch between different operating configurations (single-phase three-channel interleaved mode, three-phase boost mode, cascaded three-phase boost-buck mode) with real-time voltage adaptation, optimizing efficiency across varying operational scenarios through dynamic reconfiguration.
Solution Approach 2:
The control system dynamically changes key operating parameters including intermediate bus voltage levels, switching frequencies, and mode of operation based on detected input conditions. By adapting these parameters in real-time, the converter maintains high efficiency across different input voltages and phase configurations without requiring overly complex control logic.
3Power
If the converter uses four half-bridge totem pole switching legs, then power density is improved, but manufacturing complexity increases
Solution Approach 1:
The patent merges multiple functional requirements into a unified switching leg architecture. The four half-bridge totem pole switching legs serve multiple purposes: they can operate individually for single-phase input or in combination for three-phase input, eliminating the need for separate switching circuits for different phase types. This consolidation achieves high power density while simplifying the manufacturing process compared to having dedicated circuits for each operating mode.
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 enables efficient operation across a wide range of AC inputs, reducing hardware requirements and improving power density by effectively managing power factor correction and voltage regulation, thus enhancing the converter's versatility and efficiency in diverse applications.
Implementation Method 1
each of the first, the second, and the third nodes electrically communicatively coupled through a first, a second, and a third inductor, respectively, to an AC port
Implementation Method 2
the first half-bridge leg comprising a first pair of switches, the first pair of switches comprising a first switch and a second switch, each switch of the first pair of switches electrically communicatively coupled to each other in series via a first node
Data Source
AI summary
A power-factor corrected AC/DC converter has three half-bridge legs, electrically coupled with each other in parallel, each leg having a pair of switches. Each switch of the pair is electrically coupled to the other in series via a respective node that is electrically coupled through an inductor to an AC line. The converter has a fourth half-bridge leg electrically coupled with the other legs to form an electrically parallel circuit. The fourth leg has a pair of switches electrically coupled to each other in series via a fourth node, which is selectively electrically coupleable to a neutral or a second AC line. The converter has a controller that operates the three legs as a 3-channel interleaved AC/DC boost converter and couples the fourth node to the neutral or second AC line if the input is single-phase, and as a 3-phase AC/DC boost converter if the input is three-phase.