MAIA, A. C. N.; http://lattes.cnpq.br/4351605922128864; MAIA, Ayslan Caisson Noroes.
Résumé:
Concerning the power quality, static converters are a tool widely used in power systems.
In this dissertation, five topologies of converters AC-DC-AC are studied, two of them do
not use transformer and have two DC-links, the other three use a transformer and have
a single DC-link. One of the converters studied already was mentioned in the technical
literature. This work gives a different approach from the perspective of the control and
definition of the PWM strategy.
The following aspects are discussed for each topology: (i) dynamic modelling; (ii)
PWM strategy; (iii) control of several variables of the system, i.e., input grid current
(waveform and power factor), DC-link voltage, load voltage; (iv) characterization of the
converters based on harmonic distortion of voltages and currents and conduction and
switching losses of the semiconductor switches.
For topologies that have two DC-links, is explored the possibility of operation with
different voltages in the DC-links in order to improve the performance of these structures.
For the topologies that use transformer, the optimization their performance is done
through the appropriate choice of this component (choice of transformation ratio).
The converters are suitable for applications that operate with the same frequency
in the input and output (e.g., uninterruptible power supply - UPS), voltage regulated
sources, harmonic compensators, etc). In order to validate the studies performed in this
work, results were obtained from simulations and experimental tests.
