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Aiming at the travel model of electric vehicle, a travel chain method is proposed to describe the daily travel rule of electric vehicle users. The characteristics of the time chain are fitted by the mixture Gaussian distribution and the normal distribution, and the parameters are estimated by the maximum expectation algorithm and the maximum likelihood estimation. The regional transfer probability model of the electric vehicle is established on the space chain to analyze the driving path and the remaining electricity of the electric vehicle under the conditions of charging and not charging. In this paper, Freud algorithm is used to find the shortest path between the starting point and the end point of EV in the network. The actual case is selected for analysis and calculation. The calculation results show the effectiveness and practicability of the established model and algorithm.

Due to new energy, such as photovoltaics, character with intermittent and volatility, when connected to the grid, it seriously affects the voltage fluctuation of the distribution network system. Which brings new challenges to traditional voltage regulation technology. In order to solve these challenges, the energy storage technology is proposed. Firstly, from the positional relationships between the energy storage access points and the research nodes, the factors that cause the node voltage changes are studied. According to the voltage change difference caused by different energy storage access locations, the priority siting areas of energy storage are deduced. Then, the heuristic optimization method is used to find out the minimum power value of energy storage. This power value is the minimum value of energy storage to make each node’s voltage within a safety domain when voltage distorts for the grid-connected photovoltaic. Afterwards, the effective location areas for energy storage are found by comparing the minimum power value in different situations. Finally, the correctness of the conclusion is verified by the IEEE33 node system. The simulation results show that the closer the energy storage location is to the end of the line, the more obvious improvement effects of system voltage will be, as well as the smaller energy storage capacity.

Aiming at the traditional forward-backward method not processing PV nodes of active distribution network power flow calculation, a correction algorithm based on a fixed change-rate matrix is proposed. The change-rate matrix is used to solve the reactive power compensations of PV nodes, thereby indirectly transforming PV nodes into PQ nodes. The derivation and solution of the fixed change-rate matrix are studied. Theory proves that there are linear relationships between the voltage corrections and the reactive compensations of PV nodes. The elements of the change-rate matrix are constant and are not related to values of the reactive compensation. The muliple power flow calculation method is used to solve the fixed change-rate matrix, which overcomes the error caused by the direct calculation of transfer reactance, thus improving the convergence of the algorithm. The proposed algorithm is validated by the IEEE 33-node system with PV-type DGs. The simulation results show that the proposed algorithm has good convergence, and the convergence of the algorithm is weakly sensitive to the number and the initial reactive power values of PV-type DGs.

In past investigations on the interaction of laser and optical films, research was not widely performed on the process after the burst of the films’ material. Based on a centrosymmetric burst model of a plasma droplet, combined with ionization and absorption, the conditions that the ejected droplet’s thermodynamic parameters change with time have been investigated. When the burst starting time is appropriate, research has shown that the droplets’ parameters, such as expansion velocity and acceleration, cracking velocity and acceleration, temperature, and radius will reach their maximums. An earlier or later time does not increase the intensity of the droplet’s burst. This conclusion has great significance in investigations of laser-induced films damage.

The conditions that the droplet's thermodynamic parameters change with time have been calculated, and the contrast between them when different laser pulse patterns are selected have been analyzed accordingly. The results show that: Two atomization processes are formed, and the second one is not evident for the case of gaussian distribution laser pulse. The change trend of the time-related expansion velocity is first increased, then decreased for the case of flat top distribution laser pulse, and is first increased, then maintained for the case of gaussian distribution laser pulse. The expansion process displays a stable stage in which the expansion velocity fluctuates slightly after atomization for the case of gaussian distribution laser pulse. In the terminal phase of the laser pulse, negative expansion acceleration appears for the case of flat top distribution laser pulse. The time-related temperature variations are more complicated for the case of flat top distribution laser pulse.