Autotransformer AC/DC Converter Mass Reduction
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Solution Overview
Problem
The existing AC/DC converters with autotransformers face challenges in reducing mass and volume, particularly in aeronautical applications, due to the need for oversized interphase inductors to block disturbing voltages between rectifier bridges.
Innovation Solution
An AC/DC converter design featuring an autotransformer with a primary winding connected to an AC power supply and secondary windings connected to rectifier circuits, where the outputs are connected to coils wound on a common magnetic core, replacing the two interphase inductances with a single inductance to reduce mass and volume.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two separate interphase inductors are used to block disturbing voltages between rectifier bridges, then the converter can operate reliably, but the mass and volume of the converter increase
Solution Approach 1:
The patent combines two separate interphase inductors into a single shared inductor with a common magnetic core. The first and second inductors are merged such that they share a common magnetic path and core structure, reducing the total mass and volume while maintaining the necessary inductance values for blocking disturbing voltages between the two rectifier bridges.
Solution Approach 2:
The shared inductor performs multiple functions simultaneously: it serves as the interphase inductor for both rectifier bridges, provides magnetic coupling between the bridges, and maintains the necessary voltage blocking capability. This multi-functionality eliminates the need for separate dedicated inductors for each bridge.
2Reliability
If two separate interphase inductors are used to block disturbing voltages between rectifier bridges, then the converter can operate reliably, but the volume of the converter increases
Solution Approach 1:
The patent combines two separate interphase inductors into a single shared inductor with a common magnetic core. The first and second inductors are merged such that they share a common magnetic path and core structure, reducing the total mass and volume while maintaining the necessary inductance values for blocking disturbing voltages between the two rectifier bridges.
Solution Approach 2:
The windings of the first and second inductors are nested around the same magnetic core, with one set of windings positioned inside or adjacent to the other. This nested arrangement allows both inductors to occupy overlapping spatial volumes, significantly reducing the overall volume required compared to having two separate, non-overlapping inductor assemblies.
3Volume of stationary object
If a single shared inductor is used to reduce mass and volume, then the converter becomes more compact, but the complexity of designing for aeronautical applications increases
Solution Approach 1:
The patent combines two separate interphase inductors into a single shared inductor with a common magnetic core. The first and second inductors are merged such that they share a common magnetic path and core structure, reducing the total mass and volume while maintaining the necessary inductance values for blocking disturbing voltages between the two rectifier bridges.
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 design significantly reduces the mass and volume of the converter, facilitating its use in aeronautical applications by minimizing the size of the intercircuit inductor while maintaining effective harmonic rejection and smoothing capabilities.
Implementation Method 1
the said first, second, third and fourth coils are wound on a common magnetic core
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
The converter has an autotransformer (30) with a primary coil connected to an alternating current (ac) supply network and secondary coils connected to rectifier circuits (40, 46). The circuits function in parallel to deliver a direct voltage to a load. The circuits have outputs (44a, 50a) respectively connected to one of the ends of coils (56a, 56b) and outputs (44b, 50b) connected to respective ends of coils (56c. 56d). Other ends of the coils (56a, 56b) are connected to form an output terminal (58a) of the converter, where the coils (56a-56d) are wounded on a common magnetic core (54).