The paper presents the adopted concept in implementing the supervision, control, monitoring and protection functions for 110 kV and 20 kV substations. The article describes the structure of the existing SCADA system, the approach adopted in implementing new facilities, the main performances of RTUs and the main functions of the computer-based control and monitoring centre. The concept of open systems architecture adopted for the SCADA system inherently offers an increased control system availability and improved upgradeability. The authors also present the development and the main algorithms used to achieve a digital protection equipment for medium voltage (MV) power systems. The equipment includes protection functions, automation functions as well as metering functions for isolated neutral networks or earthing through a resistor or an arc suppression coil. An important task of the equipment is the capability to be integrated in SCADA systems.