THREE-STAGE FILTERING COMPENSATING PLANT OF AC TRACTION NETWORK Russian patent published in 2019 - IPC H02H7/16 

FIELD: electrical engineering.

SUBSTANCE: filtering compensating unit (CFU) of traction AC network of systems 25 and 2×25 kV comprises main switch, three CFU sections connected in series, in each of which capacitor bank and reactor are connected in series, as switching switches there are two thyristor keys shunting the first and second CFU sections. Installation additionally includes chain of series-connected damping resistor and damping resistor switch, connected in parallel to CFU third section reactor, and control unit with two inputs and four outputs for on / off switching of thyristor keys, main switch and damping resistor switch, current sensor connected in series with CFU sections, and a voltage sensor of CFU buses, the output of which is connected to the first input of the control unit, and the output of the current sensor is connected to the second input of the control unit. First output of the control unit is connected to the control input of the main switch, the second and the third outputs of the control unit are connected to the control inputs of the first and the second thyristor keys respectively, the fourth output of the control unit is connected to the control input of the damping resistor switch. Control unit is designed so that at reduction of current voltage value on CFU buses ranging from U1 to U2 the first thyristor switch shunts the first section of CFU, and with further reduction of voltage in range from U2 to U3 the second thyristor switch shunts the second CFU section, wherein the moment of closure of each thyristor switch coincides with the moment of transition of the instantaneous voltage value on the capacitor battery of the section through the zero value, and before closing the thyristor key when the current passes through the zero value for a short time, the damping resistor switch is switched on.

EFFECT: reduction of current and voltage surges during CFU sections switching intended for effective reduction of electric power losses in traction network and increase of carrying capacity at high traction loads.

1 cl, 1 dwg