Online monitoring system for lightning arrester of power system

Abstract

The invention discloses an online monitoring system for a lightning arrester of a power system. The ground (low voltage side) converts electric energy into optical energy through an optical power transmission module, transmits the optical energy to a power conversion module located in an elevated position (high voltage side) through an optical fiber and converts the optical energy into DC voltage(electric energy), thereby achieving power supply for an online monitoring device for the lightning arrester. Compared with an existing energy supply mode, the online monitoring system has the advantage that the energy is transmitted by adopting the optical fiber, so that power supply equipment (an optical power transmission module of the ground) is completely electrically isolated from electric equipment (the online monitoring device for the lightning arrester). Meanwhile, the transmitted laser (optical energy) is not affected by electromagnetic interference, so that transmission in the optical fiber is not disturbed by external factors. Finally, by adopting a ground energy supply mode, the online monitoring system is safe and reliable for a long period of time.

Description

technical field [0001] The invention belongs to the technical field of lightning protection, and more specifically relates to an online monitoring system for lightning arresters in electric power systems. Background technique [0002] The lightning arrester is an important device to ensure the safe operation of the power system, and its own operation status will directly affect the safety of the power system. Under the rated operating voltage, a normal surge arrester is equivalent to an insulator, and there will be no action. However, in the case of high voltage generated by lightning, the arrester will work to guide large current into the ground, effectively protecting various equipment in the power system. If the arrester fails or fails, once the lightning overvoltage invades, it will cause immeasurable loss of life and property. Under the development trend of the energy Internet, with the expansion of the grid scale, it is more and more important to study the online mon...

AI Technical Summary

Problems solved by technology

[0004] There is a current blind zone in the traditional coil acquisition (CT power acquisition) energy supply method, and it will not be able to provide sufficient power when the bus current of the high-voltage transmission line is extremely small

However, the principle of high-voltage capacitor voltage divider energy supply is similar to that of coil harvesting energy supply, so there are theoretical defects; in addition, there are many difficulties in adopting this method: first, how to ensure the electrical isolation between the energy harvesting circuit and the subsequent working circuit , which requires more stringent overvoltage protection and electromagnetic compatibility design. Secondly, this method has more error sources. Various factors such as temperature and stray capacitance will affect the performance of this method. Therefore, the stability of the power supply The power and reliability are worse than CT, and the second is that the power obtained by this method is limited. Although the power output can be adjusted by changing the size of the capacitor C, an excessively large capacitor will cause more problems.

Battery power supplies power to the high-potential side electronic circuits. Although it is simple and does not require the design of special electronic circuits, the battery life is short, the working environment requirements are too high, and it is relatively easy to damage. It does not meet industrial requirements and is generally used as an auxiliary power supply.

The output of solar energy is easily affected by factors such as light intensity, external ambient temperature, and seasonal changes, and it is difficult to obtain a stable power output

This is due to the inherent defects of solar cells, and the conversion efficiency of solar cells. This is because the energy provided by this method is limited, which limits its application.

However, new energy supply methods such as ultrasonic and microwave are too demanding. The main problem lies in equipment cost and conversion efficiency. Therefore, these new functional methods have not yet reached the level of real practicality, and further research is still needed.

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