Banca de QUALIFICAÇÃO: LELIO RIBEIRO SOARES JUNIOR

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : LELIO RIBEIRO SOARES JUNIOR
DATE: 28/04/2023
TIME: 14:00
LOCAL: Sala de Seminários (Espaço Sérgio Barroso)
TITLE:

A QUATERNIONIC APPROACH TO THRE-PHASE PHASE LOOKED LOOP

KEY WORDS:

Three-phase quaternions, three-phase electrical unbalances and harmonic distortions, symmetrical components decomposition, grid frequency, three-phase PLL control.

PAGES: 106
BIG AREA: Engenharias
AREA: Engenharia Elétrica
SUBÁREA: Circuitos Elétricos, Magnéticos e Eletrônicos
SPECIALTY: Circuitos Eletrônicos
SUMMARY:

This work is about an alternative of mathematical modeling of three-phase signals. The three signals are treated together, as a single entity and interpreted as the characterization of a vector in three-dimensional space. Despite this vectorial geometic view, algebraically, the signals will be represented as quaternion numbers, which have their own algebra. Using such algebra we will develop methods to determine important characteristics of signals. In a rst moment, the question of relating the disturbances present in a three-phase signal with closed geometric curves that evolve in three-dimensional space will be attacked. Such disturbances correspond to unbalance and harmonic distortion. An instantaneous method for the decomposition of unbalanced signals into their zero-, positive- and negative-sequence components is developed. The work will also dene a parameter or an intrinsic variable associated with the three-phase signals, which corresponds to the so-called instantaneous frequency. Through the quaternionic characterization of the signals it is shown how to get this information. Finally, the question of denition of alternative reference frames to characterize the signals will be addressed, and particularly the rotating frame that allows obtaining a DC representation of the given AC signals. This characterization is closely related to the operation of a PLL system, which is used in control systems of electric power conditioners, such as active power lters and voltage regulators, among others. The treatment given in the quaternionic form to the PLL serves as a starting point for the more general treatment and control of three-phase systems. The quaternionic PLL will directly provide a mathematical operator that can be used to synchronize all three-phase signals in a system, hence they can be processed as DC signals or vectors in three-dimensional space. The advantage of a quaternionic approach to deal with a three-phase signal variable, represented by a vector, is the set of mathematical tools this algebra can provide to treat a revolving vector in three-dimensional space.

BANKING MEMBERS:
Interno - 3145900 - FERNANDO CARDOSO MELO
Interno - 404862 - FRANCISCO DAMASCENO FREITAS
Externo à Instituição - HUGO TADASHI MUNIZ KUSSABA - TUM
Presidente - 1455289 - JOAO YOSHIYUKI ISHIHARA
Externo à Instituição - RODRIGO ANDRADE RAMOS - USP