Research On Key Technologies Of Wearable Measurement Of Power Frequency Electric Field Under Transmission Lines

Electric power operators often need to climb,patrol and other operations when performing on-site operations.Therefore,it is not convenient to carry large-scale,over-weight,high-power external security warning devices.Then,the development of an electric field measurement system with wearable,adaptive different working conditions and high detection accuracy is of great significance for the safety warning of transmission lines.Safety operation stipulates that workers must wear helmets when performing electrical work,and sensors that can be built into wearable devices such as helmets are important development directions for future safety warnings for power operations.In this paper,the power operation and maintenance personnel measure the power frequency electric field through the wearable intelligent early warning helmet,and estimate the warning distance according to the measured power frequency electric field.The technical key to the safety warning problem under transmission lines is whether the wearable intelligent early warning helmet can accurately measure the space electric field.This paper analyzes the problems existing in the domestic and international research results and the research on the wearable measurement technology of the power frequency electric field under the transmission line based on the research of the laboratory team.It has been found that the introduction of the wearable device will attenuate the original electric field value,and the introduction of the operator will increase the detected electric field value,and different workers will wear the wearable device into the work area.The spatial electric field produces different effects.When the power operator is working dynamically,the angle between the measurement direction of the one-dimensional electric field sensor and the electric field line is changed,which causes uncertainty in the detection of the space electric field.In view of the above technical difficulties,this paper explores the following aspects:(1)Calculate the distribution law of the electric field under the transmission line by the analog charge method.The calculation results show that different voltage levels and the arrangement of three-phase electricity will affect the electric field distribution.Through the distribution trend of the electric field,it can be concluded that the size ofdifferent operators will have different effects on the space electric field.In the second chapter,the measurement principle of the one-dimensional flat-plate electric field sensor is also introduced,which provides a theoretical basis for the design of subsequent sensors.(2)Firstly,for the workers wearing the intelligent early warning helmet,the electric field distortion is simulated under different positions and different voltage levels in the uniform electric field and the non-uniform electric field.Then,the main reason of the electric field distortion caused by the sensor is analyzed.The electric field distortion caused by the sensing unit of different areas is simulated and the optimal structural parameters are selected.Finally,in the study of the occupancy of different voltage levels,it is found that the distortion electric field changes linearly in the "far field",and the distortion electric field changes nonlinearly in the "near field";in the third chapter,the distortion electric field is also introduced.The increase factor is used for the correction of the electric field distortion to solve the distortion effect of the conductor and the insulator under the transmission line.(3)According to the structural characteristics of the intelligent early warning helmet of power operation,the non-orthogonal layout and hardware detection circuit of the sensor are designed.Based on this,a multi-sensor information fusion method based on non-orthogonal layout is proposed to solve the influence of different attitudes on electric field measurement during the movement of workers.(4)Established a laboratory testing platform to calibrate the electric field sensor.The feasibility of the self-made sensor was verified by comparative experiments.By studying the influence of the intelligent early warning helmet and the human body on the electric field distortion,the increasing factor of the distorted electric field is obtained.Under the action of the intelligent warning helmet,the original electric field will be attenuated,and the attenuation coefficient is 0.7.Under the introduction of the human body,the original electric field will increase.Large,where the 110 kV transmission line is 1.5 meters,the increase factor of Narda is 1.35,the increase factor of sensor 1 in the non-orthogonal layout is 2.4,the increase factor of sensor 2 is 11.1,and the increase factor of sensor 3 is 3.3.It is found that the increase factor of electric field at different points in a specific scene is a constant.This parameter can solve theproblem of electric field distortion under static operation.In the dynamic work of the operator,the information fusion through the multi-field sensor is used to solve the electric field measurement problem in a specific scene.In this paper,through the theoretical calculation of different voltage levels and the simulation analysis of the operator's occupancy,the problem of electric field distortion in the wearable measurement of the power frequency electric field under the transmission line is studied.It was discovered that it was caused by the edge effect and dynamic operation of the operator wearing the intelligent warning helmet under the transmission line.In this paper,the increasing factor of the distorted electric field is used to eliminate the distorted electric field of the "far field" of the transmission line.When the operator climbs the tower,the fusion of the electric field information of the non-orthogonal layout sensor is used to solve the angle of the electric field normal vector.The problem of changing with the movement.