The strategies of distribution network reconfiguration are applicable for minimizing power loss and saving electrical energy in the distribution system. Network reconfiguration is usually represented by constant load demand so ignoring the variability of load demand causes uncertainty and misleading results in the minimization of power loss. This paper consists of two parts: first, the reconfiguration was accomplished using an optimization framework based on constant load to find sets of optimal switches. The minimization of active power loss was taken as an objective function while bus voltage, branch current and system radiality were taken as system constraints. The study was applied to a 33-bus test distribution network, which is exceedingly used as test examples for solving reconfiguration problems. Second, lists of the configurations set obtained from the first part, as well as other different optimization methods proposed earlier under constant load demand were taken as test switches. Additionally, the network in the presence of distributed generators was taken to analyze the reconfiguration under an active network. Two types of load demands; the variable load and voltage-dependent load, are proposed to represent the practical load demands. This paper presents a new method for good analysis as it defines the effect of loading levels and loading patterns on a distribution system performance for passive and active networks. The proposed approach tries to find the actual power loss under different characteristics of loads. Therefore, the probable benefit of this approach is the contribution to providing more flexibility for electrical utilities in terms of distribution system operation, while also opening new prospects in the automation of smart distribution systems.

Herein, this study presents for the first time third generation perovskite solar cells (PSCs) for enhancing the performance of off-shore oil ships. The off-shore oil ships need a high efficient hybrid solar energy- batteries system for enhancing the ships efficiency and reduce the pollutants resulting from these ships. In this study, an efficient model that consists of hybrid renewable energy system (HRES) suitable for the off-shore oil ships is presented and discussed. The model uses the PSCs as a solar energy source thanks to their high efficiency reaching now almost 26% based on nanotechnology in fabrication process. For determining the optimum quantities of the HRES model the HOMER software was used. The model succeeded in reducing the pollutants and the greenhouse gases (GHGs). The direction of the ship under study is from Dalian in China to Hurghada in Egypt where the data of electric load was chosen based on this journey which is real data. The full components of the model used are PSCs, Batteries and Diesel engine. Two PSCs arrays with 600 kW and 900 kW were used in the study beside 600 kW silicon based solar cells array for comparison between technologies of solar cells. The PSCs array were formed based on a laboratory fabricated PSCs that have 23.5 mA.Cm ^-2 as a short circuit current density, 1.085 V as open circuit voltage, 0.79 as a fill factor and 20.05% as a power conversion efficiency. The results revealed that the suggested model can help in reducing the total fuel consumption and the GHGs by 5,765,575 L and 15,592,017 kg for 600 kW silicon, 15,177,375 L and 15,662,875 kg for 600kW PSCs case, 17,634,350 L and 22,307,325 kg for 900kW PSCs case respectively related to using only diesel generator during the ship journey under the same conditions. Based on the obtained results, using the solar cells especially the recent technology base ones is attractive and highly recommended on the off-shore oil ships. This leading to both the fuel consumptions and cost reduction.

Currently, island grids are being rapidly constructed in various regions, and the stochastic nature of renewable energy generation output provides a great challenge for the economic dispatch of island grids. In terms of demand-side management, the models used in existing studies in considering time-of-use pricing as well as interruptible loads are still relatively simple, which makes it difficult to fully utilize their potentials in scenarios where the number and types of controllable loads in the distribution network are increasing. For this reason, this paper firstly analyzes the time response characteristics of users participating in interruptible load protocols. Moreover, this paper proposes corresponding time-domain compensation means, and establishes a multi-type active load model based on time-of-use pricing. Secondly, the time-of-use pricing setting and the optimal scheduling of the active distribution network are integrated into a unified optimization problem in order to strengthen the guiding effect of the time-of-use pricing mechanism on the users and to achieve the overall economic optimization. Finally, a mixed integer nonlinear programming model for day-ahead and intraday integrated scheduling is developed to consider the source-storage-load characteristics within the distribution grid. Compared with the constant tariff model and the traditional TOU model, the co-optimization method of time-of-use pricing formulation and active distribution grid dispatch are improved in terms of economic efficiency of the island grid.

This work proposes the techno-economic analysis of a three-phase, three wire grid integrated third-generation perovskite solar cells-wind energy conversion system (PSC-WECS) controlled by a two-level voltage source converter (VSC) which is driven by the application of polynomial zero-attracting least mean square (PZA-LMS) algorithm. The proposed algorithm enhances the dynamic performance of the system by introducing sinusoidal grid currents with low total harmonic distortion (THD) which enhances system performance by providing acceptable outcomes under dynamic loading, fluctuating wind velocity, and solar insolation by compensating for load reactive power and balancing load and power demands at the point of coupling. This work replaces the conventional silicon PVs with PSCs to improve the economics of power generation thanks to their higher efficiency. For relative comparisons, the performance of the proposed 36kWPSC-WECS is compared with the conventional silicon PV-WECS. The results reveal that the proposed system has a low net present cost (NPC) of $68843 compared to the conventional system which costs $160917, translating to a reduction of 58% in total cost. Sensitivity Analysis (SA) is performed to analyse the dependence of optimal solutions on the uncertainty of key variables namely NPC, cost of energy (COE), windspeed & insolation. The results show that the total NPC is more sensitive to the COE and the average wind speed as compared to the other variables. Moreover, the area covered by the proposed system is reduced by 50% while as the cost of power generation is reduced by 72% due to the high efficiency of PSCs. The results obtained in MATLAB/Simulink and HOMER to determine the optimum quantity of the renewable energy sources (RES) model demonstrate the effectiveness of the recommended system.