A wide-area differential protection system and method thereof

Abstract

The invention relates to a wide-area differential protection system and method. The system comprises a central processing unit, a local unit and a time synchronization source, wherein the central processing unit is used for completing circuit and bus protection in an area, calculating main protection logic according to data sent by the local unit, and sending a control command to the locating unit according to the calculation result; the local unit is used for completing collection of communication amount and local switch information and execution of the control command sent by the central processing unit; the clock synchronization source is used for achieving clock synchronization of the local unit. According to the wide-area differential protection system and method, wide-area differential is utilized as reserve, so that the problems that maloperation, dead-zone faults and dead pixels in a digital substation occur easily in conventional failure protection are resolved; the wide-area differential protection system and method can be applied to any regional power grid on the basis that only configuration parameters are modified and procedures are not modified, therefore, the wide-area differential protection system has extremely strong vitality, maloperation when a traditional mutual inductor TA is saturated can be prevented, and the problem of the dead pixels in the digital substation is also resolved.

Description

technical field [0001] The invention designs a wide-area differential protection system and a method thereof, and belongs to the field of electrotechnical technology. Background technique [0002] Large-scale power grid interconnection puts forward higher requirements for power system relay protection. The analysis of many blackout accidents in foreign countries shows that the traditional backup protection is easy to malfunction under the abnormal operation state caused by system disturbance, causing chain tripping of the power grid. With the rapid development of wide area measurement system (WAMS) communication network, wide area protection system (WAPS) based on wide area information has been widely concerned by domestic and foreign power industry workers. [0003] The wide-area protection systems currently proposed can be divided into two categories: one is the use of wide-area information, which mainly has the functions of security monitoring, control, stable boundary c...

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Problems solved by technology

[0005] In order to overcome the deficiencies in the prior art, the object of the present invention is to provide a wide-area differential protection system and its method. The relay protection system for wide-area protection needs to be upgraded to a "surface" protection that can meet the requirements of grid interconnection. It solves the problem that the existing failure protection is prone to misoperation and dead zone failure. It can not only prevent the traditional transformer from malfunctioning when TA is saturated, but also solve the problem of bad points in the digital substation.

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