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Electric field measurement is widely used in electric power, aerospace, medical and other industries. In recent years, with the gradual expansion of the coverage of ultra-high voltage power grids nationwide, the debate about electromagnetic environment brought about by high-voltage power equipment is increasing. The electromagnetic environment pollution problem of UHV transmission and transformation lines has aroused widespread public concern. The research on the electromagnetic environment of high-voltage transmission systems is rapidly emerging in China.

The charged haze particles will affect the electric field of a high-voltage direct current (HVDC) transmission line and insulator contamination, and even result in pollution flashover. Based on the meshless local Petrov–Galerkin method, the influence of ionized electric field on haze particles’ motion is investigated using numerical calculation and experiments. Example of a coaxial electrode model is studied to verify the validation of the proposed method at first. It is proven that the proposed method agrees well with the measurements. Then, the motion principle of haze particles around an actual HVDC insulator is calculated under different ionized field levels. The result shows that the path of the charged haze particles will deflect along the electric field line driven by the electric field force, accelerating the precipitation of the haze particles on the dc insulators. Also, the contamination accumulation gets worse under severe pollution weather and high-voltage side of insulator.

Derivative method, which avoids pathological solution of the magnetic field inverse problem, was proposed to solve the problem of drawing loss or unknown of grounding grids. First, a shape function was introduced to describe the distribution of magnetic field which is perpendicular to the surface of grounding grids. Since its odd-order derivatives contain main peaks, the 1st-, 3rd- and 5th-order derivatives were chosen to solve the topology of substation grounding grids and measure the branch current of the grid by determining the position and value of main peak, respectively. Numerical example and experimental result show that the 1st- and 3rd-order derivative method works well with low error and less computation.

Suspension insulators are widely used in power systems to provide electrical insulation and mechanical support for high-voltage (HV) transmission lines. To detect and replace the faulty insulators on power transmission lines is of great importance for the safe operation of the power system. A nontouch electric-field measurement method to detect faulty ceramic insulators is presented, which involves measuring the electric-field of measuring points in the vicinity of insulator strings and calculating the potential distribution along HV outdoor insulator strings. It also suggests a way to process the influence from the tower. The salient feature of this method is the significantly smaller number of measuring points and the greater distance between measuring points and insulator strings. Ceramic suspension insulators of 110-kV voltage ratings have been modeled under clean and dry surface conditions. Good agreement is obtained between the present calculations and the actual value, which demonstrates the practical viability of the technique

With the development of power system and the constant attention to the security of equipment and personnel, fault diagnosis of grounding grid gets more and more attention. In this paper, a new fault diagnosis method for grounding grid based on damped least square QR-factorization algorithm is presented. Firstly, a magnetic field reconstruction method based on the magnetic field method is presented and then a calculation method for magnetic field above grounding grid is proposed. Afterwards, in order to solve the ill-posed reconstruction equations, a damped least squares QR-factorization algorithm is used. Finally, a simulation example is used to verify the feasibility and accuracy of the algorithm. The simulation results show that the reconstructed magnetic field and actual magnetic field are very close; the reconstruction method can also be used when the original data have some errors. So the magnetic field reconstruction method in this paper can be applied to fault diagnosis of grounding grid.

In order to analyze electromagnetic environment in present high voltage converter station, measurements in SMX converter station were carried out. Results indicate that power frequency electric field and magnetic field at many measuring points are beyond the basic national standards, and necessary shielding measures should be taken, in addition, exposure time in the converter station should be minimized. Noise interference and wireless interference in the converter station is below the limit.

Insulators for overhead lines are considered to be of basic importance to the transmission system. This paper describes a new method to check defective ceramic insulators by finding the solution of the inverse problem in the system containing insulators strings. Measure the electric field of given points in the vicinity of high voltage insulators string, calculate the voltage distribution of the insulators by charge simulation method (CSM) and Newton method. Compare it with normal voltage distribution to check whether there are defective insulators in the string and the position of them