Os conversores ressonantes para aquecimento e fusão por indução são amplamente empregados devido as suas inerentes vantagens, como eficiência, controlabilidade e uniformidade do produto. Neste trabalho analisam-se e comparam-se as topologias de potencia e configurações de controle de fornos de indução. Com os resultados desta analise e das pesquisas realizadas, e proposta uma configuração de potencia e controle, bem como de circuitos de proteção para comprovação em um protótipo. As metodologias e técnicas de projeto para os componentes de potencia, controle e proteções, e suas coordenações, são empregados na implementação do protótipo. A construção e o funcionamento do protótipo bem como a medição do desempenho permitem a verificação da validade das hipóteses de projeto e a viabilidade da proposta.

Current-source converters are mainly applied in high voltage direct current (HVDC) transmission systems. Line commutated converters are adopted, in rectifier and inverter modes. As line commutation needs reactive power, such converters are unfeasible for feeding isolated loads (with no local generation), as well as systems with low short circuit power. Converters with independent switching control are needed. It can be obtained by using: - forced-commutation schemes for converters with conventional thyristors; - converters with self-commutated electronic switches (GTOs, IGBTs etc). Typical uses for these converters could be HVDC line taps and superconduting inductors for energy storage, both with current source characteristics. A revision of line commutated converters is done, in order to standardize the notations, as well as to show such converters limitations. A survey on alternatives for HVDC systems taps is done, and the self-commutated converter with series tap is adopted for analysis in this work. Two types of controllers for this converter are analysed, the dead-beat controller and the vector controller. System performance for both controllers is measured by a digital simulation software. The solutions presented here are limited by the switching frequency (hundreds of Hz) and voltage ripple at the alternating current (AC) side. The first limitation has technological characteristic, with satisfactory solution at mid term. The second limitation, as well as the first, has solution employing multiconverter configurations, for which analysis and simulation are presented in this work.