CONTROL DEVICE OF TRANSIENT AND SUSTAINED SHORT CIRCUIT IN ALTERNATING CURRENT CONTACT NETWORK Russian patent published in 2010 - IPC G01R31/02 

FIELD: electricity.

SUBSTANCE: device includes residual voltage transformer connected to contact network with sectioning point. Switches connect contact network and "two wires-rail" line to buses of traction substation. Crank relay with coil and with contact closing with delay and time relay are connected to power supply through in-series connected closing contacts of repeating relays of the switch protections. Filter decreases the level of higher harmonic components in the curve of residual voltage supplied to input of low-frequency filter (LFF) with range of transmission of 0…48 Hz and to input of comparing unit through time relay contact closing with delay. Outputs of LFF and comparing unit are connected to input of amplifier the output of which is connected to output relay. Additional pushbutton switches the device to the search mode of sustained short circuit.

EFFECT: enlarging functional capabilities of the device owing to providing the search of damage by using induced voltage effect.

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