Multi-Phase DC/DC Converter With Switchable Resonant Gain Control
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Solution Overview
Problem
Conventional DC/DC converters face challenges in achieving high power density, reduced losses, and efficient operation at or near resonant frequency, especially in bidirectional applications, due to fixed gain curves and increased winding losses with frequency, which limits their efficiency and versatility in applications like battery charging and discharging.
Innovation Solution
A multi-phase DC/DC converter circuit with a primary side switching circuit and secondary side rectifier circuit, featuring multiple switching and rectifier legs, resonant capacitor networks, and a transformer configuration that allows operation at or near resonant frequency, enabling efficient bidirectional operation and adaptable voltage gain characteristics through switchable resonant capacitor configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If operation frequency is increased to reduce converter size, then power density is improved, but winding losses increase due to proportional increase in resistance
Solution Approach 1:
The patent divides the converter into multiple phases (3-phase or 6-phase topology), segmenting the power processing into parallel channels. This allows operation at higher frequency for compact size while distributing current across multiple windings, reducing the current per winding and thus the I²R losses proportionally to the square of the phase number.
Solution Approach 2:
The patent changes the operating parameters by enabling frequency-independent gain control through resonant capacitor switching. This allows the converter to operate at optimal resonant frequency for minimal losses while achieving required voltage gain through capacitor configuration rather than frequency adjustment, maintaining efficiency across different operating conditions.
2Adaptability or versatility
If voltage gain is adjusted to meet battery voltage variation criteria, then adaptability is improved, but converter losses increase when operated away from resonant frequency
Solution Approach 1:
The patent implements dynamic switching between different resonant capacitor configurations (series/parallel connections) to adapt the gain characteristics. This dynamic reconfiguration allows the converter to maintain operation at or near resonant frequency across a wide range of voltage gain requirements, eliminating the need to operate at non-optimal frequencies for voltage adaptation.
Solution Approach 2:
The patent changes the resonant capacitor configuration parameters (connection topology and capacitance values) to achieve different voltage gains. By switching capacitor configurations rather than adjusting frequency, the converter maintains optimal resonant operation while adapting to different battery voltage conditions, preserving efficiency.
3Adaptability or versatility
If bidirectional topology is implemented to expand use-cases, then versatility is improved, but efficiency is compromised as charging operations are optimized at the expense of discharging operations
Solution Approach 1:
The patent designs a universal bidirectional converter topology that can operate efficiently in both charging and discharging modes. The symmetric circuit structure and control strategy enable optimal resonant operation in both directions, eliminating the need to trade off efficiency for one mode over the other while providing expanded functionality.
Solution Approach 2:
The patent implements dynamic control that adapts the resonant capacitor configuration and switching patterns based on the operating direction (charging or discharging). This dynamic adaptation allows the converter to maintain optimal resonant frequency operation and high efficiency in both forward and backward modes, regardless of the specific operating conditions.
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 achieves high power density, reduced losses, and efficient operation in both unidirectional and bidirectional modes, optimizing energy efficiency and flexibility for various applications by allowing operation closer to resonant frequency and adjusting gain characteristics as needed.
Implementation Method 1
A multi-phase DC/DC converter circuit with a primary side switching circuit and secondary side rectifier circuit, featuring multiple switching and rectifier legs, resonant capacitor networks, and a transformer configuration that allows operation at or near resonant frequency
Data Source
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AI summary
The invention concerns a multi-phase DC/DC-converter circuit (1), comprising a primary side switching circuit (2) comprising a plurality of primary side switching legs (3), wherein each primary side switching leg (3) comprises two or more switch elements (4); at least one secondary side rectifier circuit (5) each comprising a plurality of secondary side rectifier legs (6), wherein each secondary side rectifier leg (6) comprises two or more rectifier elements (7); a transformer (8), wherein the transformer comprises a primary side (9) connected to the primary side switching circuit (2) and a secondary side (10) connected to each of the at least one secondary side rectifier circuit (5); and at least one resonant capacitor network (11), each connected to the primary side (9) or to the secondary side (10) of the transformer (8), wherein each resonant capacitor network (11) comprises a plurality of capacitors (12).