The research program focused in solving the theoretical problems that could enable higher security and better power-system control, improve the quality of power-system operation, assure reliable supply of the end users and stimulate new sources of energy. Developed solutions are related to: - Assessment of the voltage security and definition of the preventive measures against voltage collapse; - For the Slovenian regulatory agency, we developed a software package for congestion management; - Development of an efficient concept of voltage control by introducing suitable voltage profile that also results in reducing of the transmission losses. The effort was directed in the new design of the demand side management based on voltage regulation. This regulator is specially designed for the slovenian distribution networks with lack of state information; - Market simulator coping with whole problem complexity and development of compete model of Slovenian marketplace and power system planning with ongoing development of reasonable solution-making concept. The simulator was developed for the Slovenian regulatory agency; - Development of new tools for forecasting of stochastic processes supplemented by solutions for optimal production control (dispatch).