Dual Active Bridge Circuit With Variable Inductance and Turns Ratio
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Solution Overview
Problem
Current DAB circuits face inefficiencies due to fixed inductance designs that compromise performance under varying operating conditions, leading to suboptimal electrical energy conversion efficiency.
Innovation Solution
A DAB circuit design that dynamically adjusts inductance and transformer turns ratio based on input and output voltage conditions to ensure optimal inductance for soft switching of switch transistors, using multiple inductors with varying inductance values to maintain high efficiency across different operating states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed inductance design is used in the DAB circuit, then the circuit structure is simple, but the electrical energy conversion efficiency deteriorates under varying operating conditions
Solution Approach 1:
The patent applies the dynamics principle by replacing the fixed inductance design with a dynamic inductance adjustment mechanism. Multiple inductors with different inductance values are connected through switching circuits that dynamically select and adjust the total inductance based on real-time operating conditions (input voltage, output voltage, power level). This dynamic adaptation ensures optimal electrical energy conversion efficiency across varying operating conditions while maintaining manageable circuit complexity through modular architecture.
2Device complexity
If the transformer turns ratio is fixed, then the transformer design is simple, but the power conversion efficiency deteriorates when input and output voltages vary
Solution Approach 1:
The patent implements dynamic turns ratio adjustment by dividing the transformer into multiple winding sections that can be independently connected or disconnected through switching circuits. Based on the input voltage and output voltage levels, the control system dynamically selects the appropriate combination of winding sections to achieve the optimal turns ratio. This dynamic configuration maximizes power conversion efficiency across different voltage conditions while keeping the transformer design organized and manageable.
Solution Approach 2:
The transformer is segmented into multiple primary windings and secondary windings with different turns ratios. By connecting these segmented windings in series or parallel configurations through switching circuits, the patent achieves variable effective turns ratio. This segmentation allows the transformer to adapt to different voltage conversion requirements without requiring a completely different transformer design for each operating condition.
3Device complexity
If inductance is not adjusted dynamically, then the control system is simple, but the soft switching performance deteriorates under varying voltage conditions
Solution Approach 1:
The patent employs a feedback control mechanism where the control system continuously monitors the input voltage, output voltage, and power level. Based on this feedback information, the control system dynamically adjusts the inductance by selecting appropriate inductor combinations and configures the transformer turns ratio accordingly. This closed-loop feedback ensures optimal soft switching performance across varying operating conditions while maintaining a relatively simple control architecture through standardized control logic.
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 design achieves improved electrical energy conversion efficiency by optimizing inductance and transformer turns ratio, ensuring zero voltage switching and maximum transmission power under varying input and output voltage conditions.
Implementation Method 1
The transformer is configured to perform voltage conversion on an input voltage input by the primary-side DC power supply and obtained through the primary-side single-phase full-bridge circuit, to obtain an output voltage
Implementation Method 2
The inductor unit is configured to provide a corresponding inductance when the first switching unit switches the turns ratio, to adjust power conversion efficiency of the primary-side single-phase full-bridge circuit and/or the secondary-side single-phase full-bridge circuit
Data Source
AI summary
A dual active bridge (DAB) circuit, a power supply, and a direct current to direct current (DC-DC) converter are provided. The DAB circuit includes a primary-side DC power supply, a primary-side single-phase full-bridge circuit, a transformer module, a secondary-side single-phase full-bridge circuit, and a secondary-side DC load connected in sequence. The first switching unit is configured to switch a turns ratio of the transformer according to the input voltage and the output voltage. The inductor unit is configured to provide a corresponding inductance when the first switching unit switches the turns ratio, to adjust power conversion efficiency of the primary-side single-phase full-bridge circuit and/or the secondary-side single-phase full-bridge circuit. The DC-blocking unit is configured to isolate a DC voltage on a secondary side of the transformer and output an alternating current (AC) voltage on the secondary side of the transformer to the secondary-side single-phase full-bridge circuit.