Substation cable lightning strike interference detecting device and method

Abstract

The invention discloses a substation cable lightning strike interference detecting device and method and belongs to the field of power system substation electromagnetic compatibility. The substation cable lightning strike interference detecting device and method aim at recognition of interference of lightning impulse to substation cables and interference caused by other interference sources, and utilizes the H-S conversion technology to extract energy and the maximum of various frequency bands of voltage interfering signals and corresponding characteristic frequency. Compared with the prior art in which small wave packages are used for extracting characteristic values, the H-S conversion can effectively filter interference such as noise. The detecting device and method automatically recognize the type of interference sources and interference modes through a support vector machine. Compared with a neural network, the detecting device and method are small in number of needed samples, short in training time, free of overall optimal solution problems, and good in stypticity so as to be high in recognition rate. The detecting device and method provide a basis for taking effective measures to control and remove disturbance signals in secondary cables, and avoid error operation of secondary equipment connected with a cable or equipment damage.

Description

technical field [0001] The invention belongs to the field of electromagnetic compatibility of power system substations, and in particular relates to a detection device and method for lightning strike interference of substation cables. Background technique [0002] At present, my country's power system is developing in the direction of high voltage, large capacity and intelligence. As the assembly point of power transmission and distribution in the power system, the substation gathers many primary equipment such as circuit breakers, transformers, lightning arresters, and secondary equipment such as data acquisition systems, communication systems, and relay protection systems in a limited space. The electromagnetic compatibility of the substation in the power system has become an important factor to ensure the safe and reliable operation of the power system. With the improvement of substation comprehensive automation technology, the miniaturization, digitalization and network...

AI Technical Summary

Problems solved by technology

Especially after the substation adopts a layered distributed protection and control system, some secondary equipment is directly distributed to the high-voltage switchyard of the substation. Since the primary system tends to operate at high voltage and large capacity, it will in turn have a stronger impact on the secondary circuit. Electromagnetic interference causes secondary equipment misoperation or equipment damage, which in turn affects the safe operation of the power system and poses a serious threat to the safety of the power grid

In the National Electric Power Dispatching and Communication Center, there are 215 accident cases in the "Analysis of Typical Faults of Power System Relay Protection" edited by the editor-in-chief, among which there are 92 incorrect protection actions caused by secondary system problems, accounting for 42%. It constitutes the main hidden danger of the safe operation of the substation

Transient electromagnetic fields generated by lightning strikes, switch operations, system short-circuit faults, etc. will generate interference voltage and current at the port of the secondary equipment through the secondary cable, which will affect the normal operation of the secondary equipment and even threaten the safe operation of the entire system.

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