An intelligent decentralized energy management strategy for the optimal electric vehicles' charging in low‐voltage islanded microgrids

SF6 is a kind of greenhouse gas used in electrical equipment,metal melting,electronic and atmosphere tracer,which was mentioned in Kyoto Protocol.The application situation of SF6 in electrical equipment was discussed in this paper;the research direction and development trend were proposed,and several suggestions were made for decreasing the SF6 content in power system.

The Application Situation of SF_6 in Electrical Equipment and Some Problem

The recent researches on the arc quenching characteristics of SF6 substitute gases are reviewed,including the researches by ABB and RWTH Aachen University of Germany,Toshiba,Nagoya University,Tokyo Denki University of Japan,Hyosung of South Korea,and Xi'an Jiaotong University of China.It is found that the research works in this field are very active,which continually provides theoretical and technical supports for the development of new-type high voltage electric apparatuses.

Survey of Recent Researches on the Arc Quenching Characteristics of SF_6 Substitute Gases

Switched capacitor based single DC source boost multilevel inverter (S2-MLI) featuring isolation based soft charging with minimum device count

In recent years, the research on seeking the substitute of SF6 has become an imperative case that should be resolved for scientists and the electricity sectors. From the perspective of partial discharge insulation properties, this paper measured the PDIV-(negative partial discharge inception voltage) and PDIV+(positive partial discharge inception voltage) of CF3I/CO2 and CF3I/N2 gas mixtures in different gas pressures, mixing ratios and electrodes distances, and calculated their synergistic effect, meanwhile, the PDIV-, PDIV+ and synergistic effect of CF3I/CO2 gas mixtures were compared with that of CF3I/N2 gas mixtures. The results show that the PDIV- and PDIV+ of CF3I/CO2 gas mixtures were respectively 1.2 times and 1.0~1.4 times of CF3I/N2 gas mixtures under the same testing condition, and its synergistic effect was much better than CF3I/N2 gas mixtures. Therefore, compared with CF3I/N2 gas mixtures, CF3I/CO2 gas mixtures with mixing ratio of 25~30% is more suitable for being used in low medium voltage gas insulated equipment as the insulation substituting of SF6 gas after the comprehensive consideration of liquefaction temperature, effects on environment and PD insulation characteristics.

Experimental Research on the Partial Discharge Insulation Properties of CF_3I/CO_2 and CF_3I/N_2 Gas Mixtures

Aiming at the economic benefits, load fluctuations, and carbon emissions of the microgrid (MG) group control, a method for controlling the MG group of power distribution Internet of Things (IoT) based on deep learning is proposed. Firstly, based on the cloud edge collaborative power distribution IoT architecture, combined with distributed generation, electric vehicles (EV), and load characteristics, the MG system model in the power distribution IoT is established. Then, a deep learning algorithm is used to train the features of the data model on the edge side. Finally, the group control strategy is adopted in the power distribution cloud platform to reasonably regulate the coordinated output of multiple energy sources, adjust the load state, and realize the economic operation of the power grid. Based on the MATLAB platform, a group model of MG is built and simulated. The results show the effectiveness of the proposed control method. Compared with other methods, the proposed control method has higher income and minimum carbon emission and realizes the economic and environmental protection system operation.

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Microgrid Group Control Method Based on Deep Learning under Cloud Edge Collaboration

Abstract SF6 gas is a kind of gas medium widely used in the insulation of power equipment. However, due to the greenhouse effect of SF6, new environmentally friendly gas that can instead of SF6 has been the goal for researchers. CF3I gas is one of the most promising alternative gases for SF6. In this paper, two-term Boltzmann equations of CF3I/N2/CO2 ternary gas mixture at 0.1 MPa and 300 K are calculated to obtain an electron energy distribution function (EEDF), an electron drift velocity Ve, a critical fold breakdown field strength (E/N)cr of the ternary mixed gas, and the synergy effect coefficient is used to analyze the synergy effect between the mixed gases. The calculation results show that the CF3I/N2/CO2 ternary mixture has a synergistic effect, and the 50% CF3I/40% N2/10% CO2 ratio scheme makes the mixed gas most likely to replace SF6 from the physicochemical properties. Comparing the calculated data of this paper with the data of other works of literature, the validity of the calculation method and calculation data in this paper is verified, which provides theoretical support for the research of SF6 alternative gas.

Study on the insulation characteristics of environmentally friendly CF3I/N2/CO2 mixed gas

Station Service Voltage Transformers (SSVT) combines the operating characteristics of power transformers and the design characteristics of measuring voltage transformers. Due to its lower initial cost and higher power supply reliability, its applications have been extended beyond that of auxiliary power. During transient events in the network caused by the operation of switching equipment or short circuits, the transformers are affected by the oscillating voltage, which, under certain conditions, can cause resonance overvoltage inside their windings. Based on the ATP-EMTP platform, the ferromagnetic resonance of SSVT is simulated and its simulation model, simulation algorithm, and waveform are analyzed. Based on the simulation analysis results, this paper puts forward the preventive measures of transformer ferromagnetic resonance from the perspective of voltage harmonics and insulation coordination.

Jingru Zhang

Papers

Microgrid Group Control Method Based on Deep Learning under Cloud Edge Collaboration

Study on the insulation characteristics of environmentally friendly CF3I/N2/CO2 mixed gas

Research On Ferromagnetic Resonance Overvoltage Based On Station Service Voltage Transformers

Research on fault clearing scheme for half-bridge modular multilevel converters high voltage DC based on overhead transmission lines

Fast recovery strategy for MMC-HVDC based on coordination of fault current suppression and adaptive restart