Theoretical connection from the dielectric constant of films to the capacitance of capacitors under high temperature

Abstract In the process of coping with energy and environmental protection issues, technologies such as energy materials, energy devices, and energy systems have made great progress. With excellent performance, film capacitors play an increasingly important role in energy‐related fields. With the increase of application scenarios and the continuous development of film material technology, it is urgent to establish a better theoretical connection from films to capacitors. First, the main components of the capacitor including the film and the positional relationships among them are given. Then, from the two perspectives of indirect calculation according to the volume and the direct calculation according to the winding process, the equation between the dielectric constant of films and the corresponding capacitance of capacitors is established. Further, the measurement data and error analysis results of the built test platform prove the accuracy and great potential of the proposed calculation methods. In addition, error sources, including film thickness uniformity, are listed. Finally, the challenges faced by the proposed calculation methods and the paths that can be referenced for future research are summarised and discussed.