Beyond Standard MKP Capacitors - Development of Special Metallized Polypropylene Film Capacitors for Resonant Applications in Lighting Industry

摘要

The lighting industry is constantly demanding higher efficiency electronic ballast and ignitors in to increase the life of tubes. In order to achieve increased efficiencies, the gas ignition and heating of the lamp electrodes are also being unproved by EBT and ESL designers. This leads to higher voltages, currents and ignition periods on the output stage of the lamp and the resonant capacitor. The use of thicker dielectric film to withstand these conditions seems to be the immediate logical answer. As the lighting industry is seeking smaller dimensions along with improved efficiencies, this option which involves thicker dielectric, larger dimensions and bigger components is not suitable. Another factor to consider is the fact that the increase of efficiency in new designs of ballast, accompanied by miniaturization results in elevated operating temperatures. This paper describes the results that we achieved by the use of higher quality of raw materials, process improvements and design optimization. The results achieved has allowed us to upgrade the performance of existing Metallized Polypropylene Film Capacitors and has further made it possible to present a new range of MKP capacitors with the following advantages: 1. Reduced size. 2. Higher root-mean-square voltage for each frequency. 3. Higher operating temperature. 4. Higher peak voltages for short-periods (heating plus ignition). This new range of Metallized Polypropylene Film Capacitors for resonant applications in Lighting Industry is expected to provide cost effective solution to Ballast designer's requirement for increased AC Voltage handling capability. Capacitance values up to 22 nf at 700 V AC are envisaged with 15 mm LS in this new series.