The concept of interconnected multi-microgrids (MMGs) is presented as a promising solution for the improvement in the operation, control, and economic performance of the distribution networks. The energy management of the MMGs is a strenuous and challenging task, especially with the integration of renewable energy resources (RERs) and variation in the loading due to the intermittency of these resources and the stochastic nature of the load demand. In this regard, the energy management of the MMGs is optimized with optimal inclusion of a hybrid system consisting of a photovoltaic (PV) and a wind turbine (WT)-based distributed generation (DGs) under uncertainties of the generated powers and the load variation. A modified Capuchin Search Algorithm (MCapSA) is presented and applied for the energy management of the MMGs. The MCapSA is based on enhancing the searching abilities of the standard Capuchin Search Algorithm (CapSA) using three improvement strategies including the quasi-oppositional-based learning (QOBL), the random movement-based Levy flight distribution, and the exploitation mechanism of the prairie dogs in the prairie dog optimization (PDO). The optimized function is a multi-objective function that comprises of the cost and the voltage deviation reduction along with stability enhancement. The effectiveness of the proposed technique is verified on standard benchmark functions and the obtained results. Then, the proposed method is used for energy management of IEEE 33-bus and 69-bus MMGs at uncertainties conation. The results depict that the energy management with inclusion of WTs and PVs using the proposed technique can reduce the cost and summation of the VD by 46.41% and 62.54%, and the VSI is enhanced by 15.1406% for the first MMG. Likewise, for the second MMG, the cost and summation of the VD are reduced by 44.19% and 39.70%, and the VSI is enhanced by 4.49%.

In this paper, a novel optimization method called Slime Mould Algorithm (SMA) for solving the ELD and CEED problem is presented. To investigate the effectiveness of the proposed algorithm, the 10 and 40 units considering the valve point loading effect test has been executed. The solving the Economic Load Dispatch (ELD) and Combined Economic and Emission Dispatch (CEED) are crucial task in modern power systems. The aim of ELD is assigning the best generation scheduling for minimum cost generation with satisfying the load demands while the CEED means assigning the best generation scheduling for cost and emission reduction simultaneously. The effectiveness of the proposed algorithm is compared with other algorithms.

The aim of this paper to assess the optimal site and size of photovoltaic (PV) generation-based DG along with Distribution Static Synchronous Compensator (DSTATCOM) in the real distribution network East Delta Network (EDN). In this paper, a new optimization method called Slime Mold Algorithm (SMA) simulates the oscillation mode of a slime mold in nature. DSTATCOMs and PV modules are applied to reduce losses, voltage profile and enhance stability while meeting the limitations of equality and inequality in the system. Evaluation is provided with only PV modules installed, DSTATCOMs installed only and PV modules installed with DSTATCOM. The simulations verified that the optimization of PV modules combined with DSTATCOMs can significantly enhance system performance compared to PV only modules or DSTATCOMs and the effectiveness of the proposed algorithm for allocating PVs and DSTATCOMs in terms of objective functions.

Aim. to compare between manifest, cycloplegic and wavefront refraction in different grades of myopia. Methods. 100 myopic eyes were included. The data collected included: age, sex, manifest refraction, cycloplegic refraction, wavefront refraction and pupil diameter. Manifest refraction was acquired by autorefractometer (NideK). Cycloplegic refraction was acquired after applying cyclopentolate eye drops 1% for an hour. Wavefront refraction was acquired by the iDesign aberrometer (Hartmann Shack Aberrometer) (Visx, USA) using a 32 × 32 lenslet array and near infra-red light with a wavelength of 780 nm. Results. The study showed that the wavefront refraction using the iDesign aberrometer (Hartmann-Shack aberrometer) gives higher values for each of sphere, cylinder and spherical equivalent followed by the manifest autorefraction using the Nidek autorefractometer and lastly cycloplegic refraction in all grades of myopia. Conclusions. Regarding the three methods of refraction (manifest, cycloplegic and wavefront), our results showed that the wavefront refraction acquired by the iDesign aberrometer (Hartmann Shack Aberrometer) shows higher values for each of sphere, cylinder and spherical equivalent, followed by manifest refraction acquired by autorefractometer (NideK) and lastly cycloplegic refraction in all grades of myopia.

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