Power estimation of a DBD device supplied by a current source converter is studied in this article, pointing out the prominent contribution of the transformer parasitic elements. The impact of the stray capacitance and magnetizing inductance is stated and an iterative method that estimates the electrical power and DBD waveforms is presented. Results show that the magnetizing inductance can enhance the electrical power without changing the current ratings of the converter and that the stray capacitance must be minimized. Moreover, the experimental results reveal the need for a better DBD model to properly estimate the power. In consequence, an improved model is proposed and validated using a DBD excimer lamp in a wide range of electrical operating conditions.