SF6 breaker opening current real-time acquisition and processing method of switched capacitors and reactors

Abstract

The invention discloses an SF6 breaker opening current real-time acquisition and processing method of switched capacitors and reactors. The SF6 breaker opening current real-time acquisition and processing method of switched capacitors and reactors includes the steps: 1) constructing an SF6 breaker opening current acquisition topological structure; 2) monitoring the auxiliary contact of a high voltage breaker in real time by means of an acquisition unit, determining the information of opening / closing of the high voltage breaker, and taking the time point to determine to capture the opening / closing instantaneous current value and performing wave recording, wherein the wave recording time is 100ms before or after the motion of the auxiliary contact; 3) selecting an SPI storage chip to satisfy high speed for data transmission, taking regard of the reliability of the system at the same time, selecting an I<2>C bus to satisfy normal information communication, only receiving instantaneous data access of opening / closing of the high voltage breaker in the SPI chip, wherein the two buses cooperate with each other; and 4) transmitting the processed digital quantity which undergoes electric optical conversion to a combination unit, and then transmitting the digital quantity to an industrial control server for analysis.

Description

technical field [0001] The invention relates to a method for real-time acquisition of the opening current of a circuit breaker, in particular to a method for real-time acquisition and processing of the opening current of an SF6 circuit breaker for switching capacitor reactors. Background technique [0002] With the development of the economy and the rapid increase of the capacity of the power grid, the power system has higher and higher requirements for the reliability of power supply. Power equipment is the basic component of the power system and the basis for ensuring the safe, stable and economical operation of the power system. The high-voltage circuit breaker is the most important high-voltage switchgear in the power system. It plays the dual role of control and protection in the power grid. If the high-voltage circuit breaker fails, it will cause a large-scale power outage and cause huge economic losses. [0003] At present, switching capacitor reactors in substatio...

AI Technical Summary

Problems solved by technology

The high-voltage circuit breaker is the most important high-voltage switchgear in the power system. It plays the dual role of control and protection in the power grid. If the high-voltage circuit breaker fails, it will cause large-scale power outages and cause huge economic losses.

[0003] At present, switching substation capacitor reactors mainly include SF6 circuit breakers and vacuum circuit breakers. SF6 circuit breakers are used for frequent switching of reactive equipment (especially switching capacitor banks), which has the problems of low electrical life and increased loop resistance.

The use of vacuum circuit breakers for frequent switching capacitors has a longer electrical life, but in some cases there may be problems with re-ignition and overvoltage, and high-voltage circuit breakers are used as switching reactive devices more frequently than ordinary use. , so it is more urgent to ensure the reliability of high-voltage circuit breakers for switching reactive equipment in substations

[0004] However, building a data acquisition system directly based on current transformers for relay protection measurement has the following serious shortcomings: 1) Due to the characteristics of traditional current transformers, the measurement range can only be measured at the rated current of the circuit breaker and below, which is not enough to meet the requirements of circuit breakers. 2) Due to the limitation of the insulation level of the traditional current transformer, it can only be used in the line with good insulation; 3) When the SF6 circuit breaker is broken, the operating current is often greater than rated current, while the traditional current transformer will cause serious heating due to magnetic saturation, which will bring safety hazards to the power system; 4) The data sampling frequency of the real-time data acquisition system cannot meet the needs of analysis and early warning of the remaining electrical life of the circuit breaker

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