In the article ship’s three-phase power networks with variable, asymmetrical and non-linear load to compensate for the non-active components of power more and more often used active filters are presented. Getting high energy performance of active filter depends of the control algorithm. In this article ship power networks with the new algorithm calculating the active, reactive and unbalanced components to control active filter are described. Study was carried out on virtual model, implemented in the environment “Matlab- -Simulink”