This paper presents an overview of motor drive technologies used for safety-critical aerospace applications, with a particular focus placed on the choice of candidate machines and their drive topologies. Aircraft applications demand high reliability, high availability, and high power density while aiming to reduce weight, complexity, fuel consumption, operational costs, and environmental impact. New electric driven systems can meet these requirements and also provide significant technical and economic improvements over conventional mechanical, hydraulic, or pneumatic systems. Fault-tolerant motor drives can be achieved by partitioning and redundancy through the use of multichannel three-phase systems or multiple single-phase modules. Analytical methods are adopted to compare caged induction, reluctance, and PM motor technologies and their relative merits. The analysis suggests that the dual (or triple) three-phase PMAC motor drive may be a favored choice for general aerospace applications, striking a balance between necessary redundancy and undue complexity, while maintaining a balanced operation following a failure. The modular single-phase approach offers a good compromise between size and complexity but suffers from high total harmonic distortion of the supply and high torque ripple when faulted. For each specific aircraft application, a parametrical optimization of the suitable motor configuration is needed through a coupled electromagnetic and thermal analysis, and should be verified by finite-element analysis.

Overview of Electric Motor Technologies Used for More Electric Aircraft (MEA)

In this paper, two online schemes for an integrated design of fault-tolerant control (FTC) systems with application to Tennessee Eastman (TE) benchmark are proposed. Based on the data-driven design of the proposed fault-tolerant architecture whose core is an observer/residual generator based realization of the Youla parameterization of all stabilization controllers, FTC is achieved by an adaptive residual generator for the online identification of the fault diagnosis relevant vectors, and an iterative optimization method for system performance enhancement. The performance and effectiveness of the proposed schemes are demonstrated through the TE benchmark model.

Real-Time Implementation of Fault-Tolerant Control Systems With Performance Optimization

A dye-sensitized solar cell that includes a semiconductor layer, to which a photosensitive dye generating electrons is adhered; a photo electrode disposed on a side of the semiconductor layer so as to transfer electrons; and an auxiliary electrode disposed on the other side of the semiconductor layer so as to transfer the electrons, and at least one semiconductor layer and at least one auxiliary electrode are stacked alternatively. Thus, an amount of molecules of the photosensitive dye may be increased without increasing the moving distance of electrons, and the efficiency of the solar cell may be increased.

Dye-sensitized solar cell

This paper presents a method to identify and localize failures in smart grids The method is based on a carefully designed Petri net (PN) that captures the modeling details of the protection system of the distribution network and allows the detection/identification of failures in data transmission and faults in the distribution network by means of simple matrix operations The design of the PN model is carried out by carefully composing multiple PN models for single protection systems: Such an approach allows the identification of the faults despite possible strong penetration of distributed generation In order to verify the method, two case studies are discussed The results highlight that the proposed method can remove a lot of the complexity of the associated data analysis despite the possible presence of malfunctioning protection systems and misinformation due to communication and other errors

Failure Identification in Smart Grids Based on Petri Net Modeling

Microstructures and nanostructures (100) consisting of a substrate (110), an array of pillars (120) capped by metallic disc (130), metallic dots (clusters or granules) (140) disposed on the sidewalls of the pillars, and a metallic backplane (150) that can interact to enhance a local electric field, the absorption of the light, and the radiation of the light are disclosed. Methods to fabricate the structures (100) are also disclosed. Applications of the structures to enhance the optical signals in the detection of molecules and other materials on a structure surface, such as fluorescence, photoluminescence and surface enhanced Raman Scattering (SERS) are also disclosed

Structures for enhancement of local electric field, light absorption, light radiation, material detection and methods for making and using of the same

PROBLEM TO BE SOLVED: To provide a photoelectric conversion element module capable of easily and reliably establishing electrical connection between a working electrode and a counter electrode of respective photoelectric conversion elements adjacent to each other, and achieving high conversion efficiency. SOLUTION: The photoelectric conversion element module is made up of a plurality of serially connected photoelectric conversion elements each of which at least comprises: a working electrode having a semiconductor layer carrying a sensitizing dye; a counter electrode opposed to the working electrode; an electrolyte disposed between the working electrode and the counter electrode; and a sealing part for blocking contact between the electrolyte and outside air. The photoelectric conversion element module is formed by disposing the working electrode of one of two adjacent photoelectric conversion elements and the counter electrode of the other of the two adjacent photoelectric conversion elements on a single sheet-like conductive material that is independent of both of a substrate for the working electrode and that for the counter electrode. The material has conductivity and has a penetrating hole at a portion thereof. COPYRIGHT: (C)2005,JPO&NCIPI

The photoelectric conversion element module

PROBLEM TO BE SOLVED: To provide a photoelectric conversion element which has a high electrolyte retaining characteristic and a power generation characteristic, in which leakage of an electrolyte can be prevented for a long period, and which has superior safety and high durability. SOLUTION: This is provided with a transparent electrode 3 to which a semiconductor layer 4 which carries a dye is coated and adhered, a counter electrode 7 to confront with the semiconductor layer 4 of the transparent electrode 3, a frame-shaped sealing part arranged between the transparent electrode 3 and the counter electrode 7, and an electrolyte layer which is placed inside the frame-shaped sealing part and retained between the transparent electrode 3 and the counter electrode 7, and the sealing part is provided with an electrolyte injection part 10 in order that the electrolyte layer is injected between the transparent electrode 3 and the counter electrode 7, and the electrolyte injection part 10 is made to be the photoelectric conversion element which is sealed by a sealing material. COPYRIGHT: (C)2006,JPO&NCIPI

Photoelectric conversion element and its manufacturing method

This paper presents a fault-tolerant configuration for a multiple discrete control system. The distributed control nodes, such as programmable logic controllers, communicate over networks. The design methodology of an additional redundant controller using Galois field and an error-detecting code is proposed. The proposed method is implemented and tested on distributed controllers connected on a network. It is shown that the system is functional even if one of the controllers fails. From a reliability analysis, it is also shown that the proposed design method drastically improves the mean time to failure of the discrete control system.

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Fault-tolerant configuration of distributed discrete controllers

Petri net (PN) is a useful graphical and mathematical tool to model and analyze discrete event systems. The properties of PN can be classified into two types, i.e., behavioral properties and structural properties. The behavioral properties are investigated in association with the markings of PN, e.g., reachability, boundedness and liveness. On the other hand, the structural properties are just considered based on PN structure without marking, e.g., transition and place invariant. These two types of PN properties can be generally examined in order to analyze systems modeled. These properties have been studied by three methods of analysis, i.e., the coverability tree, reduction techniques, and state equations. However, many problems concerning these properties are still left unsolved. In this paper, we propose the new concept to analyze behavioral properties of PN using by the transitive matrix derived from graph theory. First, we indicate the method to convert PN into the directed graph, and introduce the labeled place transitive matrix of PN and relationship between them. Second, the behavioral properties are discussed with the power of weighted place transitive matrix. Thus, several useful concepts to obtain transition enabling firing vectors, firing times and possible firing sequence vectors are also proposed.

A research on Petri net properties using transitive matrix

PROBLEM TO BE SOLVED: To provide an electrically-conductive ink for inkjet, capable of forming an electrically-conductive film, an electrically-conductive pattern, etc., having high electrical conductivity. SOLUTION: This electrically-conductive ink for the inkjet contains electrically-conductive particles, an ionic liquid, a binder resin, and a solvent. The ionic liquid contains, for example, at least one kind of salt selected from a group consisting of an imidazolium salt, a pyridinium salt, a pyrrolidinium salt, a phosphonium salt, and an ammonium salt. The electrically-conductive particles preferably have an average particle diameter of 1 nm to 200 nm. COPYRIGHT: (C)2007,JPO&INPIT

Takashi Sekiguchi

Papers

The photoelectric conversion element module

Photoelectric conversion element and its manufacturing method

Fault-tolerant configuration of distributed discrete controllers

A research on Petri net properties using transitive matrix

Electrically-conductive ink for inkjet, electrically-conductive pattern, and electrically-conductive material