ARC PROTECTION DEVICE Russian patent published in 2023 - IPC H02H3/93 H02H7/22 

FIELD: electrical engineering; relay protection.

SUBSTANCE: well-known arc protection device containing three photodiodes with strips for their fastening, each of which is located respectively in the cable compartment, in the busbar compartment and in the circuit breaker compartment of the switchgear cell, three time relays, three intermediate relays, three indicating relays located in the relay switchgear cell cabinet, a trip coil for the electrical installation circuit breaker, a constant operating current source to which the photodiode input is connected, and is equipped with three signal amplifiers. The passages of the photodiodes are connected to the “plus” pole of the constant operating current source, the first inputs of three signal amplifiers are connected to the outputs of the photodiodes, and the second inputs of the three signal amplifiers are connected to the “plus” pole of the constant operating current source. The input of the windings of three time relays is connected to the first output of the signal amplifiers, the output of the time relay windings is connected to the second output of the signal amplifiers. The input of the contacts with a time delay for closing the time relay is connected to the plus pole of the constant operating current source, and their outputs are connected to the inputs of the intermediate relay windings, the output of which is connected to the minus pole of the constant operating current source. The contacts for closing three intermediate relays are connected to the “plus” pole of the constant operating current source and the inputs of three indicating relays are connected to them, the output of the indicating relays is connected to the input of the trip coil of the electrical installation switch, and its output is connected to the “minus” pole of the direct operating current source. The photodiodes are mounted on a plate mounted using a bolt-nut connection on strips with a slot and with the ability to move along it opposite the current-carrying bus bar.

EFFECT: reducing the complexity of the design and increase the reliability of the device for protecting cells of complete switchgears of external and internal installations from internal short circuits accompanied by an electric arc.

1 cl, 3 dwg