Lightning arrestor online monitoring device with shielding function

Abstract

The invention discloses a lightning arrestor online monitoring device with a shielding function. A signal acquisition device adopts a straight-through current transformer to measure a total current signal which flows through a grounding wire of a zinc oxide lightning arrestor, and uses a voltage acquisition module to obtain system operating voltage at the position of a secondary terminal of a voltage transformer which is connected in parallel with the zinc oxide lightning arrestor. The lightning arrestor online monitoring device with the shielding function is characterized in that a lightning arrestor surface leakage current shielding coil is arranged, the lightning arrestor surface leakage current shielding coil is wound and fixed on the upper surface of a cluster parachute at the bottommost layer of the zinc oxide lightning arrestor, the lower end of the lightning arrestor surface leakage current shielding coil and the grounding wire of the zinc oxide lightning arrestor at the lower part of the straight-through current transformer are jointly grounded. The lightning arrestor online monitoring device with the shielding function can guarantee that the leakage current and the resistive current of the lightning arrestor can be accurately measured under various weather conditions.

Description

technical field [0001] The invention relates to an on-line monitoring device, more specifically to an on-line monitoring device for a lightning arrester. Background technique [0002] Zinc oxide arresters are widely used in power grids. Zinc oxide arresters have good nonlinear volt-ampere characteristics. Under normal operating voltage, the resistance value of zinc oxide arresters is very large, which is equivalent to the insulation state. At this time, the current flowing through the zinc oxide arresters is only At the microampere uA or milliampere mA level; when the overvoltage acts, such as lightning strike, the resistance value of the zinc oxide arrester drops sharply, and the zinc oxide arrester is broken down, which is equivalent to a short circuit state, thereby releasing the overvoltage energy to protect the main The effect of the equipment; when the overvoltage disappears, the zinc oxide arrester returns to the previous high resistance state. [0003] The structura...

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Problems solved by technology

The surface resistance of the arrester is greatly affected by the weather. When it rains or the air humidity is high, the leakage current on the surface of the arrester will increase significantly. Since the leakage current on the surface of the arrester is resistive, the resistive current value measured by the online monitoring device of the arrester will inevitably be different. Accurate, it is easy to cause misjudgment of defects in normal zinc oxide arresters, which affects the judgment of the arrester status

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