Performance analysis of grid forming converters for a didactic smart grid system

Grid forming control for inverter-dominated power systems of the future is crucial as it enables more renewable penetration and provides enhanced stability. In this paper, a power system that consists of both Synchronous Machines (SM) and Grid Forming Controlled PV system is modeled and simulated in MATLAB ® /Simulink ® . Moreover, the real parameters of laboratory pieces of equipment in Manisa Celal Bayar University Smart Grid Laboratory (MCBU-SGLab) are used throughout the study. In addition, various Grid Forming Converter control methods such as droop control, matching control, and dispatchable virtual oscillator control are compared in terms of frequency stability under different conditions

Enhancing Resiliency of Integrated Space-Air-Ground-Sea Networks with Renewable Energies: A Use Case After the 2023 T\"urkiye Earthquake

Natural disasters can have catastrophic consequences, a poignant example is the series of $7.7$ and $7.6$ magnitude earthquakes that devastated T\"urkiye on February 6, 2023. To limit the damage, it is essential to maintain the communications infrastructure to ensure individuals impacted by the disaster can receive critical information. The disastrous earthquakes in T\"urkiye have revealed the importance of considering communications and energy solutions together to build resilient and sustainable infrastructure. Thus, this paper proposes an integrated space-air-ground-sea network architecture that utilizes various communications and energy-enabling technologies. This study aims to contribute to the development of robust and sustainable disaster-response frameworks. In light of the T\"urkiye earthquakes, two methods for network management are proposed: the first aims to ensure sustainability in the pre-disaster phase and the second aims to maintain communications during the in-disaster phase. In these frameworks, communications technologies such as High Altitude Platform Station(s)(HAPS), which are among the key enablers to unlock the potential of 6G networks, and energy technologies such as Renewable Energy Sources (RES), Battery Energy Storage Systems (BESSs), and Electric Vehicles (EVs) have been used as the prominent technologies. By simulating a case study, we demonstrate the performance of a proposed framework for providing network resiliency. The paper concludes with potential challenges and future directions to achieve a disaster-resilient network architecture solution.Comment: accepted in IEEE COMMA

CHEMICAL COMPOSITION AND ANTIOXIDANT ACTIVITY OF FOXTAIL LILY (Eremurus spectabilis)

Eremurus spectabilis is used as a vegetable in Turkey, especially in Eastern Anatolia region. In this study, eight E. spectabilis from different growing areas have beenanalyzed for its nutrition value and antioxidant properties. The results showed that there were significant differences among samples in terms of all above parameters. The mean values of the parameters investigated were 86.62–91.35% for water content, 4.78–5.15 for pH; 0.42–0.70% for acidity, and 0.61–1.11% for ash content. The antioxidant activity tests evaluated by using 2-diphenyl-1-picryhydrazyl (DPPH) free radical scavenging and β-carotene/linoleic acid assays indicated that the extracts of E. spectabilis samples had high antioxidant capacity. In the DPPH and β-carotene/linoleic acid systems, average values were 73.69 μg extract . ml-1 and 94.56%, respectively. The average amount of total phenolics in samples was 223 mg GAE . 100 g-1 FW. Protein, K, Ca, Mg, Fe and Cu contentsof E. spectabilis species were found higher than in some other commonly used vegetables. The results suggest that E. spectabilis could be a valuable source of antioxidants, phenolics and minerals

Inspection of the Integrity of a Multi-Bolt Robotic Arm Using a Scanning Laser Vibrometer and Implementing the Surface Response to Excitation Method (SuRE)

The integrity of a robotic arm was examined remotely via a scanning laser vibrometer (SLV) in order to detect loose bolts. A piezoelectric element (PZT) was bonded on the robot arm for excitation of surface guided waves. A spectrum analyzer generated surface waves within the 20-100 kHz range. The propagation of the waves was monitored with the SLV at the programmed grid points on the robot arm. The surface response to excitation (SuRE) method was used to calculate the spectrums of the signals, and compare the reference scan with the altered scan. Comparisons of before and after the scan showed that after loosening the bolt on the robot arm, spectrums of all the grid points changed to some extent, however, the largest changes occurred in the vicinity of the loosened bolts. The study shows that the SuRE method was capable of detecting the presence and location of loosening bolts using only one PZT element on a complex structure. There are two most important advantages of the SuRE method over the widely used impedance-based technique. The first advantage is the elimination of an expensive impedance analyzer; the second advantage is remotely monitoring capability as long as the surface is excited properly

Power plants monitoring for reverse power flow evaluation

Power plant generators are important components of an electrical energy system. They should be constantly monitored and protected in order to maintain the quality and reliability of the power supply. Otherwise, generators may occur in case of faults or incorrect operation. One of them is reverse power condition. Reverse power flow can be cause important problems if it is not considered in the protection system design. The objective of this study is to investigate of the reverse power condition of the power plants generators. For this purpose, reverse power data are collected from a cogeneration power plant generators protection relays. The relays are able to detect disturbances and when these occurs, all digital and analogical signals are stored in its memory, including the pre-fault, fault and post-fault intervals. Hence, the reverse power data, which are collected during the transition case from abnormal condition of the generators to motoring mode, present current, voltage, active and reactive power data as well as frequency variations, are analyzed for two generators

Pomological, phytochemical, and biochemical diversification of autochthonous plum genotypes preserving under same ecological conditions using multivariate analysis

Thirty-two plum genotypes preserved at Erzincan Horticultural Research Institute in Eastern Anatolia Region of Türkiye were examined in this study and the phenological, pomological, biochemical and phytochemical differences among them over a two-year period using three replicates were determined. The flowering occurred between early April and the end of April while harvest dates were between the beginning of July and the middle of September. Twenty-nine variables were subjected to multivariate analysis. Results presented a considerable phenotypic diversity of plums. The average fruit weight ranged from 6.74 to 36.05 g with high variability. The fruit color trait was one of the crucial parameters contributing to diversity and varied between white-yellow and dark purple-blackish colors. The average dry matter contents of plum genotypes changed between 13.59 and 30.40%. The dendrogram categorized the genotypes into two major clusters and four well-defined sub-groups. The principal component analysis revealed that the first eight components accounted for 84.09% of the overall variability. Phytochemicals, including total phenolics, antioxidants, flavonoid, and anthocyanin, displayed a great variability. Malic acid was the most abundant organic acid. Vitamin C, malic, oxalic, citric, tartaric, succinic, and fumaric acids showed significant differences among the genotypes. Specific sugars exhibited a considerable degree of variability with glucose being the most abundant sugar. The results represented strong positive and negative correlations between characteristics. All these results represented the variability between plum genotypes and provided knowledge that could be applied to future research. This study, being the first report on plum genotypes, demonstrated the potential of plum genetic resources conserved under the same growing conditions