Acionamento de geradores síncronos a ímãs permanentes com bobinas abertas em sistemas de conversão de energia eólica

Abstract

This work deals with wind energy conversion systems with open-end winding. Due to the expansion seen in the installation of large power wind generators, with special attention on offshore, solutions like high power multilevel converters are being researched to support this new level in power electronics. As semiconductor devices are operating close of their limits, the combination of basic elements for the construction of multilevel equipment has been a way to carry the transfer of huge power levels. The topology with open-end winding, which had been studied in high power motor drives for more than a decade, consists of not connecting the terminals with an usual star or triangle option, instead of, connecting all the terminals to two converters. From two two-level converters, with this structure in open-end winding, the behavior of three-level converters, i.e. a multilevel scheme, is reached. This case was studied connecting a permanent magnet synchronous generator to the network throughout two back-to-back converters. A computational simulation was performed using MATLAB, through mathematical models of the system, from the network to the 2MW machine. The results were analyzed based in the theory. Then, a reduced scale prototype with 10kVA was designed, built and commissioned for a similar but less powerful system. With some variations in relation to the simulated system, experimental tests were performed to validate the results obtained through the computational tool and the theoretical study.