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An Algorithm and System for Measuring Impedance in D-Q Coordinates

dc.contributor.authorFrancis, Geralden
dc.contributor.committeechairBoroyevich, Dushanen
dc.contributor.committeememberLesko, John J.en
dc.contributor.committeememberBurgos, Rolandoen
dc.contributor.committeememberBaumann, William T.en
dc.contributor.committeememberTranter, William H.en
dc.contributor.departmentElectrical and Computer Engineeringen
dc.date.accessioned2014-03-14T20:08:19Zen
dc.date.adate2010-05-10en
dc.date.available2014-03-14T20:08:19Zen
dc.date.issued2010-01-25en
dc.date.rdate2013-05-10en
dc.date.sdate2010-03-19en
dc.description.abstractThis dissertation presents work conducted at the Center for Power Electronics Systems (CPES) at Virginia Polytechnic Institute and State University. Chapter 1 introduces the concept of impedance measurement, and discusses previous work on this topic. This chapter also addresses issues associated with impedance measurement. Chapter 2 introduces the analyzer architecture and the proposed algorithm. The algorithm involves locking on to the voltage vector at the point of common coupling between the analyzer and the system via a PLL to establish a D-Q frame. A series of sweeps are performed, injecting at least two independent angles in the D-Q plane, acquiring D- and Q-axis voltages and currents for each axis of injection at the point of interest. Chapter 3 discusses the analyzer hardware and the criteria for selection. The hardware built ranges from large-scale power level hardware to communication hardware implementing a universal serial bus. An eight-layer PCB was constructed implementing analog signal conditioning and conversion to and from digital signals with high resolution. The PCB interfaces with the existing Universal Controller hardware. Chapter 4 discusses the analyzer software. Software was written in C++, VHDL, and Matlab to implement the measurement process. This chapter also provides a description of the software architecture and individual components. Chapter 5 discusses the application of the analyzer to various examples. A dynamic model of the analyzer is constructed, considering all components of the measurement system. Congruence with predicted results is demonstrated for three-phase balanced linear impedance networks, which can be directly derived based on stationary impedance measurements. Other impedances measured include a voltage source inverter, Vienna rectifier, six-pulse rectifier and an autotransformer-rectifier unit.en
dc.description.degreePh. D.en
dc.identifier.otheretd-03192010-150706en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-03192010-150706/en
dc.identifier.urihttp://hdl.handle.net/10919/26462en
dc.publisherVirginia Techen
dc.relation.haspartFRANCIS_G_D_2010.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectThree Phase AC Systemsen
dc.subjectImpedance Measurementen
dc.subjectD-Q Coordinatesen
dc.subjectRotating Coordinate Systemsen
dc.subjectPower Electronicsen
dc.subjectTransfer Functionsen
dc.titleAn Algorithm and System for Measuring Impedance in D-Q Coordinatesen
dc.typeDissertationen
thesis.degree.disciplineElectrical and Computer Engineeringen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.leveldoctoralen
thesis.degree.namePh. D.en

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