Design And Implementation Of 10kV Combined Electroscope

The electroscope is a commonly used safety equipment in the power maintenance industry,It is used to check the electrification status of the equipment.When the equipment is energized,it give the maintenance personnel a signal to ensure the safety of the maintenance personnel.At present,The most widely used electroscope in the power maintenance industry is the contact electroscope.The technology of traditional contact electroscope is relatively mature,but there are still some defects,such as the existence of power inspection blind zone,electric shock hazard of contact power inspection,and limited detection distance of inspection.Therefore,the research of a combination of contact type electroscope and non-contact type electroscope can not only solve the problem of power inspection blind zone,reduce the risk of electric shock,but also increase the detection distance,and better protect the personal safety of the maintenance personnel.It has practical research value.In this paper,the principle of contact electroscope is analyzed firstly.The principle of stray capacitance partial pressure of contact electroscope is obtained.The stray capacitance is calculated by theoretical analysis and Maxwell simulation.Then the principle of non-contact electroscope is analyzed.The electric field simulation is carried out on the transmission line model and the electric field distribution law is analyzed.According to the principle of contact electroscope,a contact probe is designed.According to the electric field distribution law,a flat-plate capacitive electric field sensor is designed.Through theoretical analysis of the electric field sensor,it is proved that the field strength to be measured has a certain proportional relationship with the induced voltage of the electric field sensor.Maxwell simulations verify the feasibility of electric field sensors in a variety of electrical environments.The hardware circuit and software flow were designed to complete the hardware production and system debugging.In the signal conditioning circuit,the contact probe output signal is subjected to a series of conditioning such as voltage and current limiting,current scaling,filtering processing,and the output signal of the electric field sensor is subjected to voltage division,voltage following,filtering and precision rectification conditioning,and the conditioned signal is sent to the single chip processing;The MCU makes a logical judgment on the two-way signal through the software program,and finally outputs an alarm signal,prompting the inspection and maintenance personnel.In addition,the MCU sends the processing result to the mobile phone App through the Bluetooth module,and the guardian promptly reminds the maintenance personnel through the display result of the mobile phone App to further protect the personal safety of the maintenance personnel.In order to verify the actual working effect of the designed electroscope,three sets of experiments were carried out,including simulation experiment,high voltage experiment and electromagnetic compatibility experiment.The simulation experiment shows that the linearity of the non-contact signal conditioning circuit is good,the output ratio of the conditioning circuit is constant at 6.2,the error between the measured value and the actual value of the signal source is less than 0.9%,and the contact experiment is performed in 20 groups with a success rate of100%.The high-voltage experiment shows that the non-contact type inspection can alarm in time when the safety distance is 0.7m,and the alarm frequency can be improved when it is closer to the charged equipment.The starting voltage of contact type electroscope is between3~4kV,which satisfies the requirements of starting voltage between 0.15U_N~0.4U_N in"DL/740-2000 Capacitor Type Electroscope".The results of the electromagnetic compatibility experiment indicate that the electroscope meets the relevant"electrostatic discharge immunity"standard and passed relevant experiment experiments.