Interleaved Boost Converter With Coupled Inductors for Current Balancing
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Solution Overview
Problem
Existing multilevel step-up dc-dc converters face limitations in achieving high voltage gain, low component stress, and small ripples while maintaining a simple topology, with issues such as limited voltage gain, high voltage stresses, and increased electromagnetic interference due to non-isolated configurations and complex control schemes.
Innovation Solution
The proposed solution integrates two boost converters with a switched-capacitor technique and coupled inductor configuration, where the first and second inductors are inversely coupled, allowing for a high voltage gain of 2/(1-d) and reducing voltage stresses across switches, diodes, and capacitors to half of the output voltage, while enabling automatic current balancing and minimizing input current ripples.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a flying-capacitor based three-level Boost converter is used to address ground isolation issues, then electromagnetic interference is reduced, but the voltage gain is limited to 1/(1-d)
Solution Approach 1:
The patent combines two Boost converters in parallel with interleaved switching, merging their capabilities to achieve both ground isolation (reducing EMI) and enhanced voltage gain of 2/(1-d), overcoming the limitation of single-converter flying-capacitor designs
2Productivity
If the voltage gain is increased to 2/(1-d) using a modified flying-capacitor topology, then voltage gain is improved, but voltage stresses across output diode and capacitor equal the output voltage
Solution Approach 1:
The patent segments the voltage stress distribution by using two parallel converter paths, where each path's components only need to withstand half the total output voltage stress, while the combined system achieves the desired high voltage gain
3Stress or pressure
If several split capacitors connected in series are used to reduce voltage stress, then voltage stress across each capacitor is reduced, but large input current ripples and high current stresses occur
Solution Approach 1:
The patent employs periodic interleaved switching between two parallel converter paths, where the switching actions are staggered in time, causing their current ripples to cancel each other out and achieve automatic current balancing while maintaining reduced voltage stress
4Stability of the object's composition
If a complicated control scheme is employed to balance flying-capacitor voltage, then voltage balancing is achieved, but device complexity increases
Solution Approach 1:
The patent designs the converter topology and interleaved switching scheme such that the flying-capacitor voltages automatically balance themselves through the inherent circuit operation, eliminating the need for complex external control schemes while maintaining voltage stability
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 achieves a high voltage gain, reduces component stress, and provides automatic current balancing without the need for additional control strategies, resulting in low input current ripples and efficient operation across a full duty cycle range.
Implementation Method 1
a first inductor being inversely coupled to a second inductor
Data Source
AI summary
A boost or DC-DC converter includes a first output and a second output, a first inductor having a first side and a second side, the first side of the first inductor being connectable in electrical communication with a first output of a power supply or DC voltage source, and a second inductor having a first side and a second side, the first side of the second inductor being connectable in electrical communication with the first output of the power supply, the first inductor being inversely coupled to the second inductor. The converter includes a first switch in communication with the second side of the first inductor and a second output of the power supply, and a second switch in communication with the second side of the second inductor and the second output of the power supply.