In work there are the analysed existent types of defence of high-voltage lines of electricity transmission (LEP), considered principles of their construction, setting, advantages and failing. The special attention is spared to the defence controlled from distance, because at the currents of damage, which change on a size, the sensitiveness of ordinary current defences changes, not always responds to request here selectivity and fast-acting. Therefore it is necessary to use such defence descriptions of which would not rely on the mode of operations of the system of power supply. The defence LEP controlled from distance answers these requirements.
chart of power supply, relay defence high-voltage LEP, controlled from distance the currents the defence, short circuit