Revista de Sistemas Elétricos e Eletrônicos

Because of their high voltage capability and open circuit failure mode, metallized film capacitors are used to reduce electromagnetic interference (EMI) in electric power mains. This paper provides an in-depth examination of metallized film capacitors used for EMI filtering, as well as their failure modes and mechanisms. Corrosion of the metallized film due to moisture ingress into the package is one of the major failure mechanisms discussed. Standards for metallized film capacitor safety, quality, and reliability are also discussed. The paper concludes with recommendations for film capacitor selection, qualification, and accelerated life testing to ensure long-term reliability.

The current focus is shifting toward the integration of small and medium-scale power plants based on renewable energy sources into the power distribution system. Solar energy is the fastest growing renewable energy source, and a single phase voltage source inverter is used to connect photovoltaic plants to the distribution system. The control requirements for the grid integrated inverter are stringent. A current controller is used to reduce harmonics in the injected current into the grid and to regulate the power exchange between the plant and the grid. This paper provides an overview of the current control strategies used for a single phase grid-connected photovoltaic inverter. Through simulation and experimental results, a comparative performance evaluation of current control techniques is also presented.