Relay protection method of transformer as well as system thereof

Abstract

The invention provides a relay protection method of a transformer as well as a system thereof. The invention adopts standardized protection equipment based on the IEC (International Electrotechnical Commission) 61850, realizes the on-site digitalization of the acquisition of analog quantities at the high voltage side and the low voltage side of the transformer and realizes the transmission of a detection signal and a control instruction by using a message of an IEC 61850 communication protocol so as to reduce errors or interference of the detection signal and the control instruction in a transmission process, improve the accuracy of relay protection action and benefit the safe and stable operation of the transformer. The relay protection method of the transformer and the system thereof in the invention reduce controller malfunctions caused by heavier secondary load of a current transformer, which is brought by transmitting an analog detection signal by the long-distance cable because of the longer distance between main equipment and protection equipment in a nuclear power station, and also solve the problem of incorrect trip caused by large grounding distributed capacitance and easy interference of a cable for the long-distance transmission of a trip instruction in case of longer distance between a beaker of nuclear power station main equipment and a controller.

Description

technical field [0001] The invention relates to the technical field of relay protection for power network transformers, in particular to a transformer relay protection method and a transformer relay protection system. Background technique [0002] The core of smart grid and digital grid is the intelligence and digital interconnection of power system facilities, and the key technology is the interconnection standard. The release of IEC 61850 has been hailed as a real global standard in the electric power field. Many international communication interface standards have been continuously introduced into China, but no standard has such a great impact on the electric power industry and even social life as IEC61850. A change in thought and technology across the industry. In the practice of digital substations in recent years, power equipment based on IEC 61850 has been successfully applied. [0003] The existing implementation method for the relay protection of auxiliary transfo...

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Problems solved by technology

[0004] However, since the current transformers on the high and low voltage sides of the auxiliary transformer of the nuclear power plant are far apart, about 1km away, and the rated current of the secondary side of the current transformer is 1A, in this case, if the current input of the protection controller still adopts the traditional If the cable input mode is used, the long-distance cable transmission of analog signals will bring a heavy secondary burden on the current transformer, which will cause errors in the analog values ​​and cause malfunctions of the protection controller; Problems such as large ground distributed capacitance and susceptibility to interference are also likely to cause false tripping of circuit breakers

Therefore, the transformer relay protection method in the prior art may make mistakes or be easily disturbed in the transmission of detection signals and control instructions, which affects the accuracy of relay protection actions and is not conducive to the safe operation of transformers.

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