EMI Filter Design for Constant Power Loads in More Electric Aircraft Power Systems

Most of power electronic converter loads and motor loads, in advanced aircraft power systems, behave as constant power loads. To attenuate the switching noise of these loads, EMI filters are needed at the input terminals. The purpose of this paper is to introduce a novel design method of double LC filters for high power constant power loads in more electric aircraft power systems. This method can guarantee the overall systems stability during large disturbances, and simultaneously, it can also meet the standards of noise attenuation. The method is based on mixed potential theory, the existence of equilibrium points and three frequency points attenuation method. The proposed design method solves the limitation of existing filter design methods, which either ignore the stability problems of constant power loads, or can just ensure system stability during small disturbances. A design example is presented in this paper, and simulation results and experimental results verify the design method.