Research On Zinc Oxide Lightning Arrester Dist Irbuted Measurement Device

Zinc oxide lightning arrester(earth-sized) for its good protective properties, flow ability, and the advantages of reliable operation and convenient maintenance, be protect ac electrical equipment from lightning over-voltage and important equipment operating overvoltage damage by mistake. However earth-sized long-term weather, temperature, lightning overvoltage and internal be affected with damp be affected with damp, aging, wrong operation under the influence of the factors such as aging, serious when can cause failure protection function, influence the safe operation of power system. Therefore, to prevent accidents, earth-sized real-time measurement is of great significance to its insulation condition.In this paper, based on the analysis of the present situation of earth-sized distributed measurement technique, based on the electrical characteristics of zno valve plates, this article through to the zinc oxide lightning arrester(earth-sized) distributed measurement principle of the research, in analyzing and comparing several earth-sized distributed online measurement method on the basis of the principle and advantages and disadvantages, choose earth-sized access voltage, current and impedance fundamental wave current characteristic parameters as earth-sized running status of the reaction, and USES the digital harmonic analysis, the analysis of feature parameters are extracted. This method is the use of voltage and the current access to separate the fundamental component of the impedance current provides the basis, and judging by the characteristic parameters of increase and decrease of earth-sized real-time running state. Distributed measuring accuracy of judging basis is isolated from the total leakage current resistance capacity symbiosis out faint resistance of the fundamental wave current. In this paper, we design a zinc oxide lightning arrester distributed measuring system, completed the earth-sized distributed measurement device of hardware and software design, production and the actual reliability verification device debugging. Zinc oxide lightning arrester are analyzed in this paper the main interference factors in the distributed measurement, and puts forward the anti-interference methods, combined with the software and hardware, to enhance the anti-interference of the apparatus.Upon completion of the sensor selection, the selection of the microprocessor, the input voltage, current input circuit, the input signal conditioning circuit, lightning counting circuit, A/D circuit, clock circuit, power circuit, RS485 interface circuit and other circuit design, on the basis of all phase FFT method is used to separate out the resistance of fundamental wave current, the method has the advantage of no fixed frequency 50 Hz to improve the accuracy of the extraction ofcharacteristic, this paper also consider data loss problem in practical operations, expand an EPROM, make the data can be stored without losing more than one year, and another store Pointers EPROM, convenient search and analysis of data. Experiment conditions and to use in this paper, the design of the zno arrester distributed measuring device for the test, after debugging and field measured data shows that the zinc oxide lightning arrester distributed measuring device designed in this paper can effectively monitor earth-sized running status, has high accuracy and stability.