FIELD: machine building.
SUBSTANCE: invention relates to methods of electrochemical protection of underground metal structures against stray currents caused by rail electric transport. Method includes controlling cathode polarization of underground structures by controlling the amount of diverted stray currents from protected underground structures to the rail network depending on the magnitude of the potential "underground structure–ground" relative to the reference electrode, wherein analysis of measured values of potentials of each protected underground structure is carried out, according to result of analysis decision is made on distribution of stray currents between protected underground structures with due allowance for their mutual influence and command is sent to control stray current tap separately for each underground structure. Automatic drainage system comprises n drain circuits, wherein each drain circuit consists of series-connected fuse, switch-off switch, shunt with measuring instrument and power switch, wherein each power switch is connected to the middle point of the choke transformer, which is part of the rail network, and by welding with the corresponding protected underground structure through its drain circuit, n comparison electrodes, n low-pass filters, inputs of which are connected to corresponding underground structures and comparison electrodes, and outputs are connected to control unit, unit for decision-making on distribution of stray currents between protected underground structures and unit for synchronization of switching of power switches, where n is number of protected underground structures.
EFFECT: invention enables to ensure optimum protection of structures: simultaneous maintenance, in accordance with GOST 9.602-2005, of the protective potential "underground structure–ground" of underground metal structures with minimum required drainage current.
3 cl, 1 dwg
