Inversores entrelaçados aplicados a sistemas de energia ininterrupta

• Ano de defesa: 2010
• Autor(a) principal: Sergio Alejandro Diaz Contreras
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Engenharia Elétrica; Engenharia elétrica
• Link de acesso: http://hdl.handle.net/1843/BUOS-8CMG94

The parallelism is a commonly used technique to increase the power of the converters in order to overcome with the current limitations of the semiconductor technology. Besides, if correctly applied, the parallelism is able to grant more advantages than just the augmentation of the power of the converter. In this way, the parallel connection of inverter modules, by interleaving their control signals gives advantages like ripple reduction in the output current and voltage, allowing reducing the size of the passive elements or reducing the switching frequency. Nevertheless, this connection is sensitive to disequilibrium in the currents distribution, and generates cross-currents. This work is a study of the interleaving of half-bridge inverters; the advantages and disadvantages of the interleaving are shown by means of simulations and analytical demonstrations. Besides, this work shows the modeling and testing process of a two arm interleaved inverter with 4kVA each arm. The modeling and design of the controllers were done in the discrete time frame, and the controller was implemented in a TMS320F2812 digital processor. The system control was done with feedback by using a set of PI controllers in order to ensure the currents distribution and theregulation of the output voltage. Also, a repetitive controller was used to take the THD to acceptable limits. The obtained results show that the used methodology controls the currents distribution withoutaltering considerably the interleaving characteristics. This work presents as a contribution the analytic demonstration of the characteristics anddrawbacks of the interleaved inverters because in the literature that was found, the properties of this parallelism are only mentioned and shown by means of simulations or experimental results. So, in this work is performed a mathematic analysis of the harmonic cancellation in the output voltage, of the cross-current (its harmonic composition, its behavior and its mathematic expression) and of the ripplesthat appear in a two-leg interleaved inverter using magnetic coupling