Keskijännitejärjestelmät

Keskijännitejärjestelmät, known in English as medium voltage systems, refer to electrical power distribution networks that operate at voltages typically between 1 kilovolt (kV) and 36 kV. These systems are crucial for transmitting electricity from substations, where high voltage is stepped down, to industrial facilities, commercial buildings, and residential areas where the voltage is further reduced to lower levels for end-use. They bridge the gap between high voltage transmission lines and low voltage distribution networks.

The primary purpose of medium voltage systems is to efficiently transport electricity over moderate distances. Using medium voltage reduces the current required for a given power level, which in turn minimizes resistive losses in the power lines and allows for smaller, more economical conductors compared to low voltage systems. Common voltage levels within this range include 10 kV, 20 kV, and 30 kV, although specific levels can vary by region and application.

Components of a medium voltage system include transformers for voltage transformation, circuit breakers and switches for protection and control, cables and overhead lines for transmission, and protective relays to detect faults and isolate sections of the network. These systems are designed with safety and reliability in mind, incorporating features to prevent overloads, short circuits, and other electrical disturbances. The design and maintenance of medium voltage systems require specialized knowledge and adherence to strict safety regulations due to the significant energy levels involved.