FC switch on-off time testing and zero-sequence protection setting system and method thereof

Abstract

The invention discloses an FC switch on-off time testing and zero-sequence protection setting system and method. The FC switch on-off time testing and zero-sequence protection setting system is characterized in that a low-voltage side of a high-voltage plant transformer is connected with one side of a power incoming circuit breaker, the other side of the power incoming circuit breaker is connectedwith a plant segment bus through a bus bar, one side of a load FC switch is connected with the plant segment bus through a bus bar, and the other side of the load FC switch is connected with a load through a load cable; a low-voltage side branch zero-sequence current transformer of the high-voltage station transformer is connected with the high-voltage station transformer protection device; and an output end of the high-voltage station transformer protection device is connected with a control end of the power incoming circuit breaker, a load zero-sequence current transformer is connected witha load comprehensive protection device, and an output end of the load comprehensive protection device is connected with a control end of the load FC switch. According to the FC switch on-off time testing and zero-sequence protection setting system and the method, the problem of protection override trip caused by relatively long switching on and off time of the FC switch can be solved.

Description

technical field [0001] The invention belongs to the field of electrical technology, and relates to an FC switch closing-opening time test and its zero-sequence protection setting system and method. Background technique [0002] The FC switch is a fuse (Fuse)-contactor (Contactor) combined electrical appliance. It has the advantages of small size, frequent operation, long mechanical life, and low price. It has been widely used in medium-voltage systems in power plants and industrial and mining enterprises. GB / T2900.20-2016 "Electrotechnical Terminology for High-Voltage Switchgear and Control Equipment" stipulates that the "close-open time" of switchgear refers to the moment when the contact of the first pole contacts in the closing operation. Time interval until the moment when the arcing contacts of all poles are separated during the subsequent opening operation. [0003] For this time, high-voltage circuit breakers have specific requirements in GB1984-2014 "High-voltage AC...

AI Technical Summary

Problems solved by technology

[0005] (1) The closing and opening time of FC switch contactors with integrated closing and opening structure of some manufacturers is relatively long. Due to the limitation of the switch structure, it is difficult to solve it from the FC switch body and the transformation cost is relatively large.

[0006] (2) The setting calculation does not take into account the closing and opening time of the FC switch, and there is a hidden danger of tripping over the level

Then, when the FC power supply load is faulty, if the inherent closing-opening time of the FC switch is greater than the protection time difference, it will cause the upper power supply incoming line switch to trip, causing the entire busbar to lose power, and even the unit to shut down unplanned

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