Functional Verification of Power Electronic Systems

This project is the final work of the degree in Industrial Electronics and Automatic Engineering. It has global concepts of electronics but it focuses in power electronic systems. There is a need for reliable testing systems to ensure the good functionality of power electronic systems. The constant evolution of this products requires the development of new testing techniques. This project aims to develop a new testing system to accomplish the functional verification of a new power electronic system manufactured on a company that is in the power electronic sector . This test system consists on two test bed platforms, one to test the control part of the systems and the other one to test their functionality. A software to perform the test is also designed. Finally, the testing protocol is presented. This design is validated and then implemented on a buck converter and an inverter that are manufactured at the company. The results show that the test system is reliable and is capable of testing the functional verification of the two power electronic system successfully. In summary, this design can be introduced in the power electronic production process to test the two products ensuring their reliability in the market

Using formal methods to support testing

Formal methods and testing are two important approaches that assist in the development of high quality software. While traditionally these approaches have been seen as rivals, in recent years a new consensus has developed in which they are seen as complementary. This article reviews the state of the art regarding ways in which the presence of a formal specification can be used to assist testing

Analysis, design, fabrication and testing of an optical tip clearance sensor

Analyses and the design, fabrication, and testing of an optical tip clearance sensor with intended application in aircraft propulsion control systems are reported. The design of a sensor test rig, evaluation of optical sensor components at elevated temperatures, sensor design principles, sensor test results at room temperature, and estimations of sensor accuracy at temperatures of an aircraft engine environment are discussed. Room temperature testing indicated possible measurement accuracies of less than 12.7 microns (0.5 mils). Ways to improve performance at engine operating temperatures are recommended. The potential of this tip clearance sensor is assessed

Firms’ Contribution to Regional Economic Development: Unravelling Some Explanatory and Moderating Variables

Drawing on entrepreneurial orientation (EO), family business, strategic decision-making (SDM) and social capital (SC) theories, we investigated whether the family and non-family firms contribute differently to regional economic development (RED) and the moderating role of family involvement in firms. Using survey research design and data from 307 Kenyan firms, the findings of the study showed that: a) Firms’ EO positively influences RED, but the effect of family firms’ EO on RED is twice that of nonfamily firms; b) the relationship between strategic decision-making and RED is negative and this is more pronounced in family firms than nonfamily firms; c) Bridging social capital’s (BSC) influence on firms’ contributions to RED is positive, but nonfamily firms’ BSC effect is twice that of family firms; d) family involvement moderates the effects of firms’ contribution to RED. The overall conclusion of this study is that better understanding of firms’ effect on RED can be achieved by using a range of theories in combination, as such use would help to unpack the underlying mechanisms through which firms influence RED. Finally, theoretical and practical implications are discussed

Safety Engineering with COTS components

Safety-critical systems are becoming more widespread, complex and reliant on software. Increasingly they are engineered through Commercial Off The Shelf (COTS) (Commercial Off The Shelf) components to alleviate the spiralling costs and development time, often in the context of complex supply chains. A parallel increased concern for safety has resulted in a variety of safety standards, with a growing consensus that a safety life cycle is needed which is fully integrated with the design and development life cycle, to ensure that safety has appropriate influence on the design decisions as system development progresses. In this article we explore the application of an integrated approach to safety engineering in which assurance drives the engineering process. The paper re- ports on the outcome of a case study on a live industrial project with a view to evaluate: its suitability for application in a real-world safety engineering setting; its benefits and limitations in counteracting some of the difficulties of safety en- gineering with COTS components across supply chains; and, its effectiveness in generating evidence which can contribute directly to the construction of safety cases

Extendible-retractable electric field measurement antenna for IMP J

An antenna dispenser mechanism for the IMP J spacecraft was designed, fabricated, and tested. Upon command the mechanism deploys or retracts a conductor for use as a receiving antenna for an electric field measurement experiment. Five identical units were fabricated and tested to the IMP H & J environmental test specification. Of these, four are designated for flight on the IMP J spacecraft and one as a prototype flight spare. The testing program was successfully completed although certain design modifications were required as problems were uncovered by the testing; particularly thermal vacuum operation. The antenna mechanism functions well under the expected environmental and loading conditions. The wear life and load capability of the dry molybdenum disulphide lubricant originally used on the heavily loaded worm and gear pair were disappointing and a substitute material was applied. The lubricant finally applied performed well; although other problems were generated

Technology transfer: Transportation

The application of NASA derived technology in solving problems related to highways, railroads, and other rapid systems is described. Additional areas/are identified where space technology may be utilized to meet requirements related to waterways, law enforcement agencies, and the trucking and recreational vehicle industries