Barium strontium titanate particles with composition of Ba0.5Sr0.4Ca0.1TiO3 were prepared by sal-gel method and doped with 1% Nb2O5. Poly(ether imide) composite films were obtained by mixing particles into a poly (amic acid) solution and casting onto glass plates followed by thermal treatment. The films were investigated by Fourier transform of infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and broadband dielectric spectroscopy. They exhibited good thermal stability having the initial decomposition temperature above 773 K. The dielectric constant was in the range of 3.08-4.17 (room temperature and 1 kHz), and the dielectric loss maintained low values over a large interval of frequency and temperature. The subglass transitions gamma and beta, the alpha-relaxation corresponding to the glass transition and the conductivity process of the composite films were evidenced and correlated with the particle content. The ability to generate electrical energy on mechanical impulse was also evaluated.