Multi-Phase AC-to-DC Converter with Segmented Autotransformer
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Solution Overview
Problem
Existing composite AC-to-DC converters lack efficient voltage boosting capabilities, particularly in aerospace applications where higher output voltages are required, and traditional autotransformers experience a decrease in conversion ratio when used for voltage boosting, leading to larger and heavier components.
Innovation Solution
A multi-phase AC-to-DC converter design incorporating a three-phase autotransformer with windings arranged in a specific configuration, using a vector diagram to determine turns ratios and interconnections, allowing for high voltage boosting while maintaining a high autotransformer conversion ratio (ACR), utilizing a main and auxiliary rectifier to combine boosted outputs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a typical autotransformer is used for voltage boosting, then voltage boosting capability is achieved, but the conversion ratio (ACR) decreases leading to larger and heavier components
Solution Approach 1:
The autotransformer is divided into multiple windings arranged in legs, with each winding having specific turns ratios. This segmentation allows the voltage boosting function to be distributed across multiple smaller winding segments rather than requiring a single large transformer, thereby reducing overall weight while achieving the required voltage boost.
Solution Approach 2:
Different windings within the autotransformer are assigned different turns ratios tailored to specific phases and positions. This local optimization ensures that each winding contributes efficiently to the voltage boosting function, maximizing the conversion ratio (ACR) while minimizing the total transformer size and weight.
2Force
If interior winding turn ratios are increased to achieve voltage boost, then voltage boosting capability improves, but the winding volts*amperes (VA) sum increases reducing efficiency
Solution Approach 1:
Multiple windings with different turns ratios are combined in a parallel leg configuration, where each winding handles a portion of the power conversion. This merging allows the voltage boosting function to be achieved while distributing the VA burden across multiple paths, reducing the total winding VA sum and associated energy losses.
Solution Approach 2:
The autotransformer configuration dynamically routes power through different winding paths based on the required voltage boost level. By selectively engaging windings with appropriate turns ratios, the system achieves voltage boosting while optimizing the VA utilization and minimizing energy losses in the windings.
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 passive voltage boosting with a high ACR, minimizing the weight and size of the autotransformer while achieving a voltage boost of almost 2:1, with reduced losses and smaller auxiliary rectifier requirements, thus addressing the need for efficient and reliable power conversion in aerospace applications.
Implementation Method 1
an autotransformer connected to the main rectifier and the auxiliary rectifier, the autotransformer including a plurality of interconnected windings arranged in a plurality of legs
Data Source
AI summary
A nearly 2 to 1 boosting mufti-phase AC-to-DC converter may include a main rectifier, an auxiliary rectifier; and an autotransformer connected to the main rectifier and the auxiliary rectifier. The autotransformer may include a plurality of interconnected windings arranged in a plurality of legs, with one of the legs for each phase and with each leg including a plurality of windings, wherein all but one of the windings of each leg have equal turns ratios and one of the windings of each leg has a turns ratio that is less than the turns ratio of all of the other windings of the respective leg.