Analysis of the stability an electro energetic grid with great load converter power supply system

The paper presents a consequences of application a converter supply system in electro energetic grid of middle voltages, supplied a great power drive system (over 1000 kW), and their influences on quality of electric energy in grid of middle voltages industrial plants. In the paper presents a mathematical analysis of phenomenon to occur in industrial plants of electro energetic grid of middle voltages, with great power load systems. A computer model of electro energetic supply system are also presented in paper. For reduction of parasitic harmonics level in current supply and voltage supply are mostly applied a static capacitor filter. The paper present a solution with active power filters in reduction of high harmonics levels. Together with parasitic harmonics compensation, problem of LC resonances between the output filter of inverter and power active filter and the line inductances are analyzed. Some results of computer simulation performed for selected electro energetic grid configuration, with and without active filter are presented in the paper. Results of industrial measurement are also presented in the paper