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Once blackouts occur the system operators should re‐energise the affected system in the shortest time. To attain this, restoration plans should be developed beforehand. A deliberate restoration plan considers the supply duration of the cranking power to non‐black‐start units (NBSUs), besides the static and dynamic constraints of the power system. Hence, there should be a method to estimate the restoration duration of NBSUs considering the failure in breakers operating mechanism and the stochastic nature of restoration actions. Accordingly, in this study, generally distributed transition stochastic Petri net is employed to calculate the supply duration of NBSUs, critical loads and the execution time of restoration actions. This is significant because the planners can validate their restoration plans from the NBSUs critical times' point of view or determine energisation time of critical loads. The proposed method has been applied in three test cases, two of these are used for benchmarking, and the other one is a part of Iran bulk power system, which includes a real black‐start test. The results show the effectiveness of the method in estimating the restoration duration. [ABSTRACT FROM AUTHOR]

Summary: Blackouts rarely occur in power systems; nevertheless, in case of occurrence, its impact on the economy, industry, and social life can be noticeable. To minimize the negative financial and social impacts of blackouts, power systems should be restored in the shortest possible time. Therefore, system operators should access a formulated method to estimate the restoration duration. In this paper, a method based on the Petri Net is used to calculate the restoration duration. Therefore, a restoration plan is resolved into its constituent steps, and for each step, a stochastic duration is considered. Applying the Petri Net model of the restoration plan and the duration of each restoration step, the total restoration time can be calculated. The proposed method is applied in two system tests, and the results show consistency with those of the critical path method. [ABSTRACT FROM AUTHOR]

Arresters are widely used in power systems to protect other equipment against overvoltages. However, in some conditions, they can't operate successfully. One of the disturbances leading to the failure of the riser pole arresters is the ferroresonance overvoltages. In this paper, at first the influence of different transformer simulation models of ATP software on the occurrence of ferroresonance is studied and then the effect of ferroresonance on the riser pole arrester has been scrutinized through the thermal and electrical performance of the arrester in an underground distribution system. The results show that the arrester temperature rises due to energy dissipation in a ferroresonance circumstance, which indeed may result into the explosion of the arrester. Also, applying different models of the transformer in the ATP software and comparing the results, it is shown that the available models do not show the same effect on the arrester. [ABSTRACT FROM AUTHOR]

Summary: Despite power system operators' efforts, blackouts occur; therefore, power systems should be restored. To attain this, power system restoration is done applying different strategies after a complete blackout. The most famous one is the bottom‐up strategy. Determining the islands is of extreme importance in this strategy. Hence, this paper proposes a new version of multi‐objective populated simulated annealing considering the cohesiveness and the quality of islands as objective functions. The proposed method takes into account miscellaneous constraints such as black‐start availability in each island, load‐generation balance, power flow establishment equations, and the availability of synchronization devices. Simulation results for the IEEE 39 and 118‐bus test systems confirm the effectiveness of the proposed method in determining the islands. [ABSTRACT FROM AUTHOR]

A total of 500 fecal samples were collected from Equus animals in six different cities (Ardabil, Namin, Nir, Meshginshahr, Germi, and Khalkhal) of Ardabil Province, northwestern Iran, with 200 samples from horses, 200 from donkeys, and 100 from mules. Of the horse samples, 100 were from racing horses under special monitoring and care, while the remaining 100 were from non-racing horses, including those used for herding or in rural areas. All fecal samples were examined for the presence of Blastocystis sp. using PCR amplification of the SSU rRNA gene's barcode region after DNA extraction. The molecular prevalence of Blastocystis infection in Equus animals was 7.6% (38/500). Blastocystis was more common in horses [11.5% (23/200)] than in donkeys [5.5% (11/200)] and mules [4% (4/100)] (P > 0.05). Compared to racing horses [3% (3/100)], non-racing/rural horses [20% (20/100)] exhibited a substantially higher prevalence of Blastocystis (P < 0.05). The prevalence of Blastocystis in diarrheal samples and younger animals was remarkably higher than in formed samples and older animals, respectively (P < 0.05). No significant difference in Blastocystis infection prevalence was found between the genders of examined animals (P > 0.05). In Equus animals, 38 Blastocystis isolates included eight STs: ST10 [31.6% (12/38)], ST1 [21.1% (8/38)], ST2 [15.8% (6/38)], ST3 [10.5% (4/38)], ST4 [7.9% (3/38)], ST7 [5.2% (2/38)], ST14 [5.2% (2/38)], and ST6 [2.6% (1/38)]. These results suggest that Equus animals act as a proper reservoir for numerous Blastocystis STs, consequently playing a crucial part in the spread of this protozoan infection to humans, animals, and water reservoirs. • The present study is the first large-scale research conducted in Iran with the aim of determining the prevalence, STs distribution, and zoonotic importance of Blastocystis in Equus animals (horses, donkeys and mules). • The molecular prevalence of Blastocystis infection in Equus animals was 7.6% (38/500). • Blastocystis was more common in horses [11.5% (23/200)] than in donkeys [5.5% (11/200)] and mules [4% (4/100)]. • Compared to racing horses [3% (3/100)], non-racing/rural horses [20% (20/100)] exhibited a substantially higher prevalence of Blastocystis (P < 0.05). • All STs (ST1-ST4, ST6, ST7, ST10, and ST14) isolated from Equus animals in this study are in the group of zoonotic STs. [ABSTRACT FROM AUTHOR]