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GIS equipment is widely used in electric power production because of its many advantages, and metal particles are the main cause of insulation breakdown of GIS equipment in recent years. Particle traps are an important research value as a suppression measure. In this paper, the shielding average electric field strength and the maximum distortion electric field strength of five traps are compared by electric field simulation with different trap thicknesses, different slot widths and different slot spacings using a fully closed and semi-open coaxial cylindrical simulation platform with a circular hole-shaped trap as the object of study, so as to provide guidance for the subsequent dynamic process of particles and the trap design and layout strategy for final application.

High voltage XLPE cable has become the mainstream of power transmission equipment. At present, the application experience of cable condition diagnosis technology is insufficient, and there is still room for improvement in key issues such as technical limitations, application methods, detection cycle and evaluation criteria. Therefore, it is very important to get more accurate cable condition evaluation criteria by statistical analysis of cable faults. In this paper, the partial discharge fault of cable is analyzed. First of all, the guidelines and regulations of existing cables in China are studied, and the standards related to partial discharge and temperature in current cable condition evaluation are understood. Secondly, the typical cable fault cases are collected, the partial discharge data of the fault cable is recorded, and its distribution form is obtained. Finally, on the basis of the above research work, a calculation method of conditional fault probability of cable under given local discharge amplitude is proposed, which can reflect the severity of partial discharge fault of high voltage cable to a certain extent.

The energy Internet revolution has greatly improved users’ flexibility in using energy. The extensive use of electric heating equipment(EHE), combined cooling heating and power(CCHP) and many other equipment enables the flexible conversion of different types of energy at the user side, which has widened the regulation scope for virtual power plant(VPP) in participating in the demand response of large power grid. In this paper, a flexible operation technology framework of VPP considering the interaction between CCHP and EHE is proposed and the operation characteristics of CCHP and EHE are emphatically introduced. Then an optimal decision model for VPP considering the interaction between CCHP and EHE is proposed which could fully satisfy the user's comprehensive energy demand and aims at maximizing the operation efficiency of VPP. Finally, a case study based on the actual data of an industrial park in China is used to prove the validity of the proposed method.1

Fiber Bragg Grating (FBG) is being studied by more and more researchers in the field of electrical engineering. An integrated detection system for temperature and PD on cables based on FBG is proposed. At the same time, the method of eliminating cross-interference between temperature and PD is put forward, which ensures the accuracy of detecting temperature and the sensitivity of detecting PD. A PD detection experiment shows the detection system can detect the PD with high amplitude. And the calculation of wavelengths corresponding to the peak of reflection spectrums verifies the effectiveness of the integrated detection method.

As cable insulation failure usually started with PD activity, a PD detection system based on pulse current was built to study the PD characteristics of typical defects in XLPE cable. To facilitate the test, the oil cup test terminal was used. Considering the installation procedure, three different kinds of insulation defects in cable accessory samples were made, which were knife incision defect, metal floating potential defect and misplaced stress cone defect. Under long time power frequency voltage of U», 1.7U0, 2.5U0 and 3.5U0 (U0=8.7kV), this paper proposed a variety of methods to characterize partial discharge of these samples by PRPD spectrum, δ t spectrum and PSA spectrum. Results showed the δ t spectrum presented a clear distribution of the peak and the sub-peak. The distribution regularity of partition probability in PSA pattern before the breakdown was found that the probability in the area 1.1 as from 50% to 60%, and the probability in the area 3.1 was from 30% to 40%.

This paper analyzes the high level demand of modern industrial products for package, and the complexity of the best hard packing size design with the gradual popularization of the container logistics: too many design factors need to be considered so that the traditional experience can't afford. Only apply the optimization means can have comprehensive consideration and settlement. According to the practical difficulties encountered in the industry, this article for varies of practical problems, comparing the modern algorithms and the traditional algorithms of the commodity hard packing size container optimization design. By using different algorithms to solve many actual examples later conduct scientific method of Intercomparison results, we summarized the advantages and disadvantages of the modern algorithms and traditional algorithms for solving different scale models. It provides important reference for designers when taking the size optimization design.