Dual Active Bridge DC-DC Converter with Integrated Transformer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing DC-DC power converters for electric and hybrid electric vehicles face challenges due to high costs and complexity in designing transformer secondary stages for high output currents, requiring multiple magnetic components and additional control devices, which increases expense and tuning difficulties.
Innovation Solution
A bidirectional or unidirectional DC-DC converter employing a dual active bridge rectifier topology with a transformer having primary and secondary windings, where the secondary side is divided to double the working voltage, reducing current through components and eliminating the need for a choke on the secondary side, using the transformer's inductance for DC output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple rectifier implementations are used to achieve high output currents, then the required output current capability is met, but device complexity and cost increase due to additional power devices, driving devices, and control complexity
Solution Approach 1:
The secondary windings are divided into two separate windings (first secondary winding and second secondary winding), each connected to its own rectifier circuit. This segmentation allows the total output current to be distributed across two parallel paths, reducing the current burden on each individual rectifier and eliminating the need for multiple stacked rectifier implementations, thereby simplifying control while maintaining high output current capability
Solution Approach 2:
The transformer is designed with dual functionality: it provides both voltage transformation and current splitting. The single transformer structure with two secondary windings simultaneously achieves voltage conversion and current distribution, eliminating the need for separate current-sharing circuits and reducing overall device complexity
2Productivity
If multiple rectifier implementations are used to achieve high output currents, then the required output current capability is met, but cost increases due to additional power, driving and control devices
Solution Approach 1:
The secondary windings are divided into two separate windings (first secondary winding and second secondary winding), each connected to its own rectifier circuit. This segmentation allows the total output current to be distributed across two parallel paths, reducing the current burden on each individual rectifier and eliminating the need for multiple stacked rectifier implementations, thereby simplifying control while maintaining high output current capability
Solution Approach 2:
The transformer is designed with dual functionality: it provides both voltage transformation and current splitting. The single transformer structure with two secondary windings simultaneously achieves voltage conversion and current distribution, eliminating the need for separate current-sharing circuits and reducing overall device complexity
3Power
If LLC structure with resonant tank and isolation transformer is used, then voltage conversion is achieved, but cost increases due to need for two magnetic elements and tuning becomes challenging
Solution Approach 1:
The transformer is designed with integrated functionality, combining the isolation transformer and resonant inductor into a single magnetic component. The primary winding provides isolation and voltage transformation, while the leakage inductance of the transformer itself serves as the resonant inductor, eliminating the need for a separate resonant tank inductor and reducing the total magnetic component count from two to one
Solution Approach 2:
The transformer is designed with dual functionality: it provides both voltage transformation and current splitting. The single transformer structure with two secondary windings simultaneously achieves voltage conversion and current distribution, eliminating the need for separate current-sharing circuits and reducing overall device 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
This configuration reduces component costs, simplifies design, and enhances output current capability by halving the current through secondary components and eliminating the need for a low-voltage filter, while maintaining efficient voltage conversion.
Implementation Method 1
The transformer is configured to receive the first AC voltage and output a second AC voltage or to receive the second AC voltage and output the first AC voltage
Implementation Method 2
The first switching network is configured to receive the first DC voltage and to convert the first DC voltage to the first AC voltage or to convert the first AC voltage to the first DC voltage
Data Source
AI summary
A bidirectional or unidirectional DC-DC converter includes a primary stage and a secondary stage. The primary stage is configured to receive or output a first DC voltage. The primary stage includes a first switching network configured to convert the first DC voltage to a first alternating current (AC) voltage or vice versa. The DC-DC converter also includes a transformer having primary windings and secondary windings. The primary windings are in electrical communication with the first switching network. The transformer is configured to convert between the first AC voltage and a second AC voltage. The DC-DC converter also includes a secondary stage that has a second switching network. Characteristically, the second switching network and the transformer operate as an interleaved converter to convert the second AC voltage to an output DC voltage or vice versa. Advantageously, the required series inductance for this interleaved converter is integrated into the transformer.