Power electronics is a study of electronic circuits used for management and conversion of electric energy. Technology is a critical part of our energy infrastructure and is the central notion for a wide spectrum of electric energy use. For designing the power electronics we consider only those circuits and devices who, in principle, don`t introduce loss and achieve almost perfect reliability. Two main characteristics are high efficiency and high reliability who are performed with the help of switching circuits, completed with energy storage. In a power electronics system there are three primary challenges: the hardware problem of switching circuits implementation, the software problem of deciding how to manage those circuits and the problem of interface, that is, removing of unwanted distortion and offering the user the wanted clean energy source. The hardware is implemented with several special charging types of semiconductors. That includes several types of transistors, especially MOSFET and IGBT types, and several types of thyristors, especially SCR and GTO types. The software problem can be introduced in the terms of switching functions. Frequency, duty ratio and phases of switching functions must be available for working purpose of a certain circuit. Interface problem is solved with the mean of filter circuits without loss. They are mostly passive LC without loss for wavy smoothing or harmonic reduction. Active filter circuits are also applied for dynamic corrections in power conversion waveforms. Improvements in the devices and progress in management concepts have brought constant improvement in power electric circuits and systems. Personal computers, for example, would be enormous and inefficient without direct current electronics sources, mobile devices and laptops would also be inefficient. High lighting efficiency, motor control and a wide array of industrial controls depends on power electronics as well as high growth in automobile industry, in uninterruptible power supplies, highly sophisticated power converters, and in alternative and renewable energy. During the next generations we will come to a point where almost all electrical energy is being processed thru power electronics, from production itself to end usage. In this paper of the impact of the application of power electronics circuits and related electromagnetic disturbances in the ship's electrical power system is analyzed.