Resumo:
Power quality improvement, reliability and availability of electrical power are significant
concerns in power systems. In this context, multi-pulse converters are interface devices
between the AC electrical system and the DC link, widely used in HVDC–TS (HVDC
Transmission System) and industrial rectification of very high currents to meet harmonic
requirements on both the AC and DC sides of the converter system. This thesis proposes
24 and 48–pulse converter structures for reducing AC and DC filters in conventional
HVDC–TS and for excellent harmonic mitigation in industrial rectification, respectively,
using special three-winding transformers with ZZ–Y–D (ZigZag–Wye–Delta) or DE–Y–D
(Extended delta–Wye–Delta) connection. To prove the feasibility and applicability of both
proposed prototypes, computational simulations, under certain established operating conditions, are carried out in Matlab/Simulink to verify the theoretical studies carried out
with the help of the MathCad program. Finally, a reduced-scale prototype implementation is performed and tested according to available laboratory resources to validate the
proposed converter systems. According to the developed analyses, the results obtained
showed a theoretical-experimental consistency in terms of power quality improvement
and confirmed the feasibility and applicability of SC–24P (24–Pulse System Converter)
and SC–48P (48–Pulse System Converter) proposed.
