Research On The State Detection Method Of Power Grounding Grid Based On Radar Polarization

The standard design and maintenance testing of grounding grid are very important for the safe and stable operation of substation and transmission line.With the construction of more large-scale transmission lines and the transformation of urban power grid,the demand for grounding grid is becoming more and more high.Therefore,the detection of the state of the grounding grid makes it very important for the grounding network to meet the requirements of safe operation.In the actual detection,the method used is primitive.The traditional measurement is mostly used for excavation measurement or indirect measurement,which has certain blindness.In addition,such measurement methods often have the problems of large workload,slow speed and lack of measurement precision.The ground penetrating radar is used to detect the grounding network.Through processing and analyzing the echo with the target information of the grounding network.we get the state information of the grounding network and achieve rapid detection.In this paper,according to the characteristics of grounding grid,the two basic states of ground network dielectric conductivity and embedded depth are detected.According to the difference between the electrical properties of the grounding grid conductor and the surrounding medium,the conductivity of the medium is retrieved by the Maxwell equation.The radar images of different conductivity medium are compared and analyzed.and the conductivity information of medium is obtained.Next.the detection of buried depth of ground network is studied.The characteristics of grounding grid are analyzed and the detection principle of buried depth of ground network is introduced.The depth of buried depth is detected in the testing site,and the depth of the detection is close to the reality,and the detection effect is better.After the ground network basic state detection is realized.In this paper,radar polarization is used to study the detection methods of the conductor direction and the corrosion of the grounding grid.When studying the conductor orientation of grounding grid,the paper uses FDTD to model the scene of grounding network,studys the scattering field of conductor under different polarization receiving and sending modes,compares and analyzes the relationship between the trend and the scattered field,and gets the information of conductor orientation.It is proved that the XY and YX polarization modes are more sensitive to the direction of the conductor.In the analysis of polarization detection of grounding grid corrosion,the polarization scattering characteristics of conductor before and after corrosion are compared.The corrosion information of conductor is obtained by comparing the polarization scattering characteristics of grounding conductor before and after corrosion.Finally,under the support of the related projects,the ground penetrating radar equipment is used to detect the buried depth of the ground network.The random noise emission signal is designed to make the ground penetrating radar signal with good anti-interference and penetration in this paper.The power spectrum and variance of the transmitted signal are studied.It is found that when the power spectrum of the transmit signal is close to the class clock,it has good anti-interference performance,and the penetration is strong when the signal variance is large.