Bi-directional DC-DC Converter with Active Clamp for Aircraft Weight Reduction
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Solution Overview
Problem
Current bi-directional DC-DC converters for aircraft are bulky, heavy, and require separate equipment for boost and buck modes, leading to inefficiencies and increased fuel costs due to the need for multiple converters and complex electrical networks.
Innovation Solution
A scalable, bi-directional DC-DC converter with an active clamp branch and controlled switching elements that can operate in both step-up and step-down modes, allowing for seamless transition between modes without additional hardware, using a transformer and switching elements in half or full bridge configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate battery chargers and DC-DC inverters are used for different applications, then specific functions are achieved, but device bulk and weight increase
Solution Approach 1:
The patent implements a single bi-directional DC-DC converter that can operate in multiple modes (battery charging, DC-DC conversion in both boost and buck modes) replacing what would traditionally require separate dedicated devices. The converter achieves functional versatility through controlled switching operations that enable it to perform different functions based on operational requirements, thereby eliminating the need for multiple separate converters and reducing overall system weight.
2Adaptability or versatility
If multiple separate converters are used for different modes, then specific applications are covered, but device complexity increases
Solution Approach 1:
The converter achieves multi-mode operation (boost and buck modes) through a unified circuit topology with controllable switching elements, eliminating the need for separate dedicated converters for each mode. This universal design reduces system complexity by consolidating multiple functions into a single device while maintaining the capability to perform all required operations.
Solution Approach 2:
The patent employs dynamic control of switching elements (Q1-Q4) that can be selectively activated or deactivated based on the desired operational mode. The converter transitions between boost and buck modes dynamically through controlled switching sequences, allowing a single static circuit to perform multiple dynamic functions, thereby reducing the need for multiple dedicated circuits.
3Adaptability or versatility
If a bi-directional converter operates in both boost and buck modes, then versatility is improved, but switching control complexity increases
Solution Approach 1:
The patent implements dynamic switching control where the switching elements (Q1-Q4) are selectively activated based on the desired operational mode. In boost mode, specific switches are controlled to achieve voltage step-up, while in buck mode, different switching sequences are applied for voltage step-down. This dynamic reconfiguration of the same circuit elements enables bi-directional operation without requiring separate dedicated circuits for each mode, thereby managing control complexity through intelligent switching sequences.
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 enables a compact, high-efficiency converter that can interface with unknown power buses, handle both boost and buck modes, and perform soft start-ups, reducing weight and bulk while improving energy management and efficiency.
Implementation Method 1
a transformer (80) having a first winding (80a) that can be coupled to the first region by means of the first converter network and a second winding (80b) that can be coupled to the second region by means of the second converter network
Data Source
Figure 1
Figure 2~4
Figure 3
AI summary
A bi-directional DC-DC converter (100) to convert a first DC voltage value into a second DC voltage value, including a first cell (50) connectable between a low potential region (2) and a high potential region (4) and comprising a first converter network that can be coupled to the low potential region (2); a second converter network that can be coupled to the high potential region (4); a transformer (80) connected between the first and the second converter network; an active clamp branch (56), connected in parallel to the first converter network and including an enabling switch (62), a commutator switch (64) and a first capacitor (66) connected in series to one another. The enabling switch is kept open during operation in buck mode so as to bypass the active clamp branch (56) and closed during operation in boost mode so as to connect the active clamp branch. Furthermore, the switching of the commutator switch is controlled during the step-up voltage operating mode by means of a switching signal having a duty cycle increasing by preset steps from a minimum duty-cycle value.