Asymmetric Bridge DC/DC Converter for Wide Input Voltage Switching
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Solution Overview
Problem
Conventional DC/DC converters face issues with large volume, high cost, and reduced efficiency due to the need for two-stage conversion circuits and additional components, which require restarting when input voltage changes, leading to unstable output voltage and increased power loss.
Innovation Solution
A DC/DC converter with an asymmetric half-bridge circuitry topology that can dynamically switch between full-bridge and half-bridge modes, using control strategies to manage transformer saturation and rectifying switch voltage stress, including capacitor clamping circuits to reduce power loss and component stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If two-stage conversion circuits are used to achieve wide input voltage range, then the input voltage range is expanded, but the volume and cost of the DC/DC converter increase
Solution Approach 1:
The patent implements dynamic mode switching between full-bridge and half-bridge configurations based on real-time input voltage levels. The controller dynamically adjusts the switching topology to match operating conditions, enabling a single-stage converter to handle wide input voltage ranges without requiring two separate conversion stages, thereby reducing volume while maintaining adaptability
2Adaptability or versatility
If two-stage conversion circuits are used to achieve wide input voltage range, then the input voltage range is expanded, but the cost of the DC/DC converter increases
Solution Approach 1:
The patent designs a universal single-stage converter that can operate in multiple modes (full-bridge and half-bridge) to cover wide input voltage ranges. This multi-functional approach eliminates the need for separate two-stage conversion circuits, reducing component count and manufacturing cost while maintaining the capability to handle diverse input voltage conditions
3Reliability
If the operation mode is fixed according to input voltage, then the converter operates in a stable mode, but the converter must be disabled and restarted when input voltage changes, leading to unstable output voltage
Solution Approach 1:
The controller dynamically switches between full-bridge and half-bridge modes based on real-time input voltage detection, eliminating the need to disable and restart the converter during voltage transitions. This continuous dynamic adaptation maintains both operational stability and output voltage stability across varying input conditions
4Adaptability or versatility
If a symmetric half-bridge circuitry topology is used, then the converter can operate in half-bridge mode, but additional switching elements and voltage-divider capacitors are required, increasing volume and cost
Solution Approach 1:
The patent employs an asymmetric half-bridge circuitry topology that eliminates the need for voltage-divider capacitors and additional switching elements required by symmetric designs. The asymmetric configuration achieves half-bridge operation with fewer components, reducing circuit complexity, volume, and cost while maintaining mode flexibility
5Adaptability or versatility
If additional switching elements are used in the primary side, then the converter can switch between full-bridge and half-bridge modes, but the power loss increases and operation efficiency decreases
Solution Approach 1:
The patent extracts and eliminates unnecessary additional switching elements from the primary side by using the existing full-bridge switching elements in combination with an asymmetric half-bridge topology. This removal of redundant components reduces power loss and improves operation efficiency while retaining the capability to switch between full-bridge and half-bridge modes
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 a smaller, cost-effective DC/DC converter with improved efficiency by doubling the input voltage range and reducing power loss through dynamic and soft switching, while maintaining stable output voltage.
Implementation Method 1
a transformer (T1) including a primary winding (Np) and a secondary winding (Ns) magnetically coupled with each other
Implementation Method 2
a capacitor clamping circuit (7a) for clamping a voltage of the second rectifying switch (SRB)
Data Source
Figure 1A
Figure 1B
Figure 2A~2B
AI summary
A DC/DC converter (1, 1a, 1b, 1c) includes a switching circuit (3) and a capacitor (C1). The switching circuit (3) includes a first bridge arm and a second bridge arm connected in parallel. The first bridge arm includes a first switch (S1) and a second switch (S2). The second bridge arm includes a third switch (S3) and a fourth switch (S4). The capacitor (Cl) is electrically connected with a node (a) between the first switch (S1) and the second switch (S2). While the switching circuit (3) is switched from a half-bridge mode to a full-bridge mode, the duty cycle of the control signal for controlling the fourth switch (S4) is gradually decreased from 100% to be synchronized with the duty cycle of the control signal for controlling the first switch (S1). Then, the duty cycle of the control signal for controlling the third switch (S3) is gradually increased from zero to be synchronized with the duty cycle of the control signal for controlling the second switch (S2).