Distributive bus fast protection realization method for intelligent transformer substation

Abstract

The invention discloses a distributive low-voltage bus fast protection realization method for an intelligent transformer substation. The method is characterized by comprising the following steps that 1, sampling data from low-voltage segmented intervals and each side of a main transformer is received and synchronously processed; 2, substation area fault judging signals of equipment relevant to bus intervals in the transformer substation are received and processed; 3, the occurrence condition, the action region and the fault type of the low-voltage bus fault in the transformer substation are identified and judged; 4, the fault type is judged, the corresponding bus fault protection logic is executed according to the fault type, and corresponding control signals are output according to the protection logics; 5, the low-voltage bus fault, the switch failure, the dead area fault warning and clearing in the intelligent transformer substation are realized, and meanwhile, prompt information is output. The method provided by the invention is used for the fast clearing of the low-voltage side bus fault in the bus of the transformer substation, belongs to the beneficial supplementation for the backup protection of the transformer substation, and has the advantages that the low-voltage fast protection configuration in the transformer substation is completed, and the operation reliability of the transformer substation is effectively improved.

Description

technical field [0001] The invention relates to a method for realizing busbar protection of a substation, in particular to a method for realizing fast protection of a low-voltage busbar of a distributed intelligent substation. The invention belongs to the technical field of intelligent substations in electric power systems. Background technique [0002] At present, for general 110kV and below terminal substations, the main transformer high-voltage incoming line, 35kV, and 10kV outgoing lines are all equipped with independent protection, while the medium and low voltage buses do not have corresponding independent protection. The conventional solution to the low-side bus failure of the main transformer is to use the corresponding backup protection action to cut off. However, the general backup protection is set according to the principle of step-by-step coordination. The general setting value is between 0.8 and 2.0 seconds. The fault action time of this protection is long. Alt...

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Problems solved by technology

However, the general backup protection is set according to the principle of step-by-step coordination. The general setting value is between 0.8 and 2.0 seconds. The fault action time of this protection is long. Although the fault can be removed, the busbar is seriously deformed, equipment is burned, and insulation breakdown is caused by high current. Losses caused by faults such as falling or protecting CT (CT is current transformer) are often irreparable, and may even cause the switchgear equipment to be unusable. The reliable time period for restoring power supply and the time for power failure are relatively large

[0003] In addition, when the main transformer low-side switch has a dead zone fault or a subsection dead zone or failure fault, the fault current passes through the low-voltage side CT during the dead zone fault, and the low backup protection detects the fault current and starts protection, but the switch action fault is difficult to remove; When the low-side switch of the main transformer fails, only rely on the high backup protection to detect the fault current action to remove it; and considering the high backup protection and the low backup time delay, the time to remove the dead zone fault is longer, generally 1.5~2 seconds

In this case, even if the fault is removed, the scope of the fault caused or the remaining equipment defects and hidden dangers are more

Before restoring the power supply of the equipment, various electrical tests must be carefully carried out, otherwise there will be a greater risk of operation

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