Analysis of New Step-up and Step-down Direct Symmetric 18-pulse Topologies for Aircraft Autotransformer-Rectifier Units

This paper presents the design and analysis of a special Rectifier Unit (RU) composed of a Delta-Differential Symmetric 18-pulse Autotransformer and cascade Boost converters for applications in More Electric Aircraft (MEA), which is denominated as RU-DDS18PATR+Boost. The cascaded Boost converters provide dc-link regulation, while eliminating the need to use interphase transformers (IPTs), interphase rectors (IPRs), and zero-sequence blocking transformers (ZSBTs), thus contributing toward decreasing the complexity and at the same time increasing reliability. The proposed RU-DDS18PATR+Boost operates with an active current shaping strategy in order to meet the harmonic content restrictions imposed by the DO-160F standard, while allowing for the design of a DDS18PATR with a notable kVA rating of 21.03%. The performance of the RU-DDS18PATR+Boost was analyzed operating in a system with a supply voltage of 115VAC and variable frequency in the range of 360Hz to 800Hz, which is converted to 540VDC. Experimental results are presented corroborating the theory put forward herein, especially with regard to meeting the limits imposed by the DO-160F standard.

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“…Finally, from the equations of currents in the time domain given by (26), the RMS value of the currents drawn from the grid are obtained by (27).…”

Section: Dds-18patru: Theoretical Waveform Of Input Line Current With...mentioning

confidence: 99%

Project and Performance Evaluation on an Optimized 18-Pulse Rectifier With Delta-Differential Connection ATRU and Cascaded Boost Converters for More Electric Aircraft

et al. 2022

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“…Scheme A is a well known 18-pulse rectifier [1,6] which has a symmetrical nine-phase input voltages with a phase-shift angle of 40˚. Each diode conducts the dc current during 40˚.…”

Section: Five Practical Schemesmentioning

confidence: 99%

Autotransformer-based 18-pulse rectifiers without using dc-side interphase transformers: Classification and comparison

Oguchi

2008

2008 International Symposium on Power Electronics, Electrical Drives, Automation and Motion

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Autotransformer-based 18-pulse rectifier systems are classified from three points of view: (a) dc-side connections of diode bridges, (b) the number of phases of the diode bridge input voltages, and (c) the symmetry of the input voltage systems. Five practical systems are chosen of which system structures, voltage synthesizing methods, equivalent transformer capacities, and simulated current waveforms are presented. The total harmonic distortion of line currents are compared when the supply voltages have pre-existing voltage-unbalance and -distortion resulted from fifth harmonics. Two schemes are recommended for applications required unregulated and regulated dc voltages.

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“…The isolated transformer, such as D/Y/D transformer, has the problem of unbalanced leakage inductance of the coil winding which can lead to noncharacteristic harmonics in input line currents. Moreover, the transformer with isolation connection has large capacity which may lead to high system cost (Lucía et al, 2014;Martinius et al, 2002;Uan-Zo-li et al, 2006). To the autotransformer, there are not only magnetic coupling but also circuit coupling between the primary and secondary windings, which makes the capacity of the autotransformer much smaller than that of the isolation transformer.…”

Section: Introductionmentioning

confidence: 99%

Novel symmetrical step-down topologies of zigzag autotransformer

Wang

Chen

2019

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Purpose This paper aims to obtain a symmetrical step-down topology with lower equivalent capacity and wider step-down range under the condition of the same output. Three new symmetrical step-down topologies of zigzag autotransformer are proposed in this paper. Taking the equivalent capacity as the main parameter, the obtained topologies are modeled and analyzed in detail. Design/methodology/approach This paper adopts the research methods of design, modeling, analysis and simulation verification. First, the zigzag autotransformer is redesigned according to the design objective of symmetrical step-down topology. Second, the mathematical model of the designed topology is established, and the detailed theoretical analysis is carried out. Finally, the theoretical results are verified by simulation. Findings Three symmetrical zigzag autotransformer step-down topologies are designed, the winding configurations of the corresponding topology are presented, the step-down ranges of these three topologies are calculated and the influence of step-down ratio on equivalent capacity of autotransformer is analyzed. Through analysis, the target step-down topologies are obtained when the step-down ratio is [0.969, 1.414] and [1.414, 8]. Research limitations/implications Because the selected research object is only zigzag autotransformer, the research results may lack generality. Therefore, researchers are encouraged to further study topologies of other autotransformers. Practical implications This paper includes the implications of step-down ratio on the equivalent capacity of autotransformer and the configuration of transformer windings. Originality/value The topologies designed in this paper enable zigzag autotransformer to be applied in step-down circumstances.

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Analysis of New Step-up and Step-down Direct Symmetric 18-pulse Topologies for Aircraft Autotransformer-Rectifier Units

Cited by 27 publications

References 17 publications

Project and Performance Evaluation on an Optimized 18-Pulse Rectifier With Delta-Differential Connection ATRU and Cascaded Boost Converters for More Electric Aircraft

Project and Performance Evaluation on an Optimized 18-Pulse Rectifier With Delta-Differential Connection ATRU and Cascaded Boost Converters for More Electric Aircraft

Autotransformer-based 18-pulse rectifiers without using dc-side interphase transformers: Classification and comparison

Novel symmetrical step-down topologies of zigzag autotransformer

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