DANTAS, N. K. L.; NICOLAU KELLYANO LEITE DANTAS.; http://lattes.cnpq.br/4215806208827252; DANTAS, Nicolau Kellyano Leite.
Résumé:
Normally, for equipments connected to the grid such as power converters, active Ąlters,
controlled rectiĄers and others, phase locked loop (PLL) algorithms are used to obtain
synchronization between the electric grid and equipment. However, these PLL algorithms
often present unsatisfactory dynamic response when the electrical grid presents distortions
such as harmonics and phase steps. In this work, it is discussed performance improvements
in phase and frequency tracking for PLL algorithms. It is proposed the use of an adaptive
delay bank Ąlter (ADB Ąlter) to solve the problem of square wave PLL (PLLOQ) phase
error, when the grid presents harmonic components. Through simulation and experimental
tests, it was veriĄed that the phase error caused by harmonics can be eliminated. However,
the error correction introduced a delay of 10ms in PLLOQ dynamics. Nevertheless, this
PLL was competitive when compared to other structures, for example, those that use
adaptive notch Ąlter. Next, it is proposed to use the ideal resonant proportional (PR)
controller in PLL structures. A systematic method for designing the control parameters
of a PLL using the PR controller is presented. Performance comparisons of the classical
PLL using the proportional integral (PI) controller versus PR controller are presented by
means of simulation and experimental results, where it was veriĄed that the PLL with the
PR controller obtained a faster response in the phase and frequency detection. It was also
veriĄed, a good precision (null error in steady state) in the detection of the parameters
of interest, besides obtaining satisfactory results (it tracked phase and frequency) when
the grid presented distortions. Subsequently, the performances of the following PLLs are
compared: (1) PLL based on the Park Inverse Transformation (Park-PLL) using the PI
and PR controllers, (2) PLL based on the Generalized Second Order Integrator (SOGI-
PLL) using the PI controller and (3) Enhanced Phase Locked Loop (EPLL) with PI
controller. Through the analyzes, for diferent grid scenarios, it was veriĄed that the best
performance among these algorithms was that of the SOGI-PLL with PI controller. The
Park-PLL with PR controller obtained the fastest phase detection, while the EPLL with
PI controller obtained the slowest phase detector. Furthermore, it was observed that these
algorithms obtained null error in steady state, except when the grid presented harmonics.
Finally, a general analysis of the main results obtained in this work was carried out, where
the best PLL choices for speciĄc applications were indicated.