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This paper presents an online scheme of a wide-area-damping-controller (WADC) for controlling the inter-area oscillatory modes in interconnected power systems using wide-area power system stabilizers and measuring signals. The proposed adaptive controller includes two individual approaches WSSS for evaluating the signal participation factor selection and GPSS as a global power system stabilizer for damping inter-area oscillations. For this purpose, considering the concept of center of inertia over inter-area signals, generators with the highest interactions are determined as oscillating areas while based on evaluating signal damping ratio, proper participation factors are estimated in which GPSS with positive damping performance is developed. In real-time working mode, based on oscillatory signals gathered from WAMS data, different combinations of PSSs are evaluated in which the combinations with the best controllability on damping the oscillations are selected. The effectiveness of the proposed widearea damping controller scheme is evaluated on the IEEE test system and practical Iran national power grid with the potential of unstable inter-area oscillations. Results show the effectiveness of the proposed WADC approach for fast and secure damping of inter-area oscillation. [ABSTRACT FROM AUTHOR]

Background: If somatization is an independent personality trait, it is not clear whether it is specific to the temperament or maladaptive spectrum of personality. We aimed at the head-to-head comparison of temperament and maladaptive systems and spectra of personality to predict both somatization and somatic symptom and related disorders (SSRD). Methods: The samples included 257 cases with SSRD (70.8% female) and 1007 non-SSRD (64.3% female) from Western Iran. The Personality Inventory for DSM-5 (PID-5), Personality Diagnostic Questionnaire-4 (PDQ-4), Temperament and Character Inventory (TCI), Temperament Evaluation of Memphis, Pisa, Paris, and San Diego-Autoquestionnaire (TEMPS-A), Affective and Emotional Composite Temperament Scale (AFECTS), and Positive Affect and Negative Affect Model (PANAS) was used to data collection. A somatization factor plus temperament and maladaptive spectra of personality were extracted using exploratory factor analysis. Several hierarchical linear and logistic regressions were used to test the predictive systems and spectra. Results: All personality systems jointly predict both somatization and SSRD with a slightly higher contribution for temperament systems. When the temperament and maladaptive spectra were compared, both spectra above each other significantly predicted both somatization (R2 =.407 versus.263) and SSRD (R2 =.280 versus.211). The temperament spectrum explained more variance beyond the maladaptive spectrum when predicting both the somatization factor (change in R2 =.156 versus.012) and SSRD (change in R2 =.079 versus.010). Conclusion: All temperament and maladaptive frameworks of personality are complementary to predicting both somatization and SSRD. However, the somatization is more related to the temperament than the maladaptive spectrum of personality. [ABSTRACT FROM AUTHOR]

This paper presents an online protective scheme of estimating critical inter‐area angle for controlling the inter‐area oscillations based on evaluating the rate of changes of rotor angle oscillations as an adaptive tripping index (ATI)‐based protective zone. For this purpose, by using wide area measuring system technology, oscillatory signals Δδ and Δω are measured which based on correlation coefficients criteria, coherent groups are identified which based on evaluating oscillating areas, inter‐area signals ΔδCOI‐AB and ΔωCOI‐AB are provided. In the case of evaluating an inter‐area oscillation, the proposed ATI scheme is activated which the first zero crossing point (ZCP0) of δCOI‐AB is determined as the critical criteria for estimating unstable situation. The proposed ATI approach consists of two adaptive protective zones ATI1 and ATI2 to estimate inter‐area oscillatory and inter‐area transient instabilities, respectively. The proposed ATI is an online and non‐model‐based scheme which evaluates the system dynamic stability through two straight and sinusoidal‐based adaptive zones. The effectiveness of the proposed ATI approach is evaluated on three different test systems IEEE 39‐bus, modified IEEE 39‐bus with converter‐based low inertia sources and a practical Iran nation power grid with presenting positive effects of damping inter‐area oscillations through different operational and topological conditions. [ABSTRACT FROM AUTHOR]

Summary: The purpose of this paper is to present a model for optimal placement of distributed generation units and sectionalizing switches (relocation of the existing switches and installation of new ones) to increase distribution network resilience against the threat of transmission system outage. The proposed model is formulated as a multi‐objective optimization problem with the objectives of minimizing investment costs and maximizing load restoration. In this regard, distribution system operation during normal conditions as well as transmission system outages is considered. In addition, the unique characteristics of the real power grid in Khuzestan province in southwestern of Iran are addressed in the proposed model which makes the model applicable to the real networks with similar characteristics in many parts of the Middle East. This grid has two completely different load patterns (in terms of load curve shape and peak load) corresponding to two hot and temperate periods, which causes completely different concerns for the network's operator. The proposed model is solved using multi‐objective genetic algorithm (NSGA‐II), and it is implemented on the 33‐node test system and the results are analyzed. Moreover, it is applied to the 327‐node real‐world test system in Khuzestan province to demonstrate its applicability to large networks. In both cases, the results confirm the effectiveness of the proposed optimization model. [ABSTRACT FROM AUTHOR]

Background & Objective: Pancreatobiliary system disorders commonly include inflammatory diseases and tumors. Diagnosis of pancreatic cancer is challenging and is mostly achieved when the disease has extensively progressed, and metastasis has occurred. Therefore, this study was performed to evaluate cytopathology in the diagnosis of Pancreatobiliary malignancies, which can improve diagnostic adequacy and accuracy. Methods: A total of 116 cytopathologic results of the Pancreatobiliary system, performed in the Pathology Department of Taleghani Hospital, Tehran, Iran during 2017-2018 were selected and examined in this observational study. The frequency of different results was determined and compared with other variables. Results: The most common location of the lesions was the pancreas (47%). The lesions were categorized as malignant, benign, negative, suspicious for malignancy (SFM), and atypical in 28%, 10%, 24%, 14%, and 9% of the cases, respectively. In other cases, lesions were considered non-diagnostic. Rapid on-site evaluation (ROSE) was conducted in 25% of patients. Compatibility of the initial and final diagnoses was 100%, 50%, and 60% in cases with "malignant", "benign", and "negative" diagnoses, respectively. The sensitivity, specificity, as well as positive and negative predictive values of cytopathology in the diagnosis of Pancreatobiliary lesions were 75.8%, 92.3%, 95.9%, and 61.5%, respectively. Conclusion: Our findings indicated that half of the lesions of the Pancreatobiliary system were positive, SFM, and atypical. Fine-needle aspiration (FNA) and endoscopic ultrasoundguided FNA (EUS-FNA) were effective modalities in diagnosing Pancreatobiliary malignancies. The most important point in our experience is the increase in diagnostic sensitivity in the presence of ROSE. Therefore, the simultaneous use of ROSE and EUSFNA can reduce the need for re-sampling. [ABSTRACT FROM AUTHOR]

Increase of nonlinear loads in industries has resulted in high levels of harmonic currents and consequently harmonic voltages in power networks. Harmonics have several negative effects such as higher energy losses and equipment life reduction. To reduce the levels of harmonics in power networks, different methods of harmonic suppression have been employed. The basic idea in all of these methods is to prevent harmonics from flowing into a power network at customer sides and the point of common coupling (PCC). Due to the costs, none of the existing mitigating methods result in a harmonic-free power system. The remaining harmonic currents, which rotate in a power network according to the system impedances, may not necessarily result in an optimum harmonic power flow in terms of harmonic undesirable results such as harmonic losses or harmonic over voltage/current due to possible resonances. This paper proposes a new method to control the flow of the remaining harmonics at a power system level such that the effects of harmonics such as losses are optimized. This task is achieved by the use of series active power filters controlled in a different manner from their conventional methods. In this new application, the series active power injects a controlled harmonic voltage into a power system (e.g., a line, transformer, or other elements) to control the harmonic current (power) flow such that the overall performance of the power system is improved in terms of harmonic effects. The series active power filter in this new application is named as harmonic power flow controller (HPFC). In this paper, the theory, structure, applications, and the basics of the control method of a HPFC are described. To investigate the effects of the HPFC on the power network harmonics, an HPFC is used in the 14-busbar IEEE test system. To make the proposal more practical, an HPFC is designed for Iran north-west transmission system to alleviate the harmonic problem in this region. Simulations are carried out to show the effectiveness of the HPFC. Simulation results show that the HPFC can control the harmonic currents (power) and voltage consequently. In this paper, several control algorithms for an HPFC are also considered to achieve the desired harmonic voltages levels. [ABSTRACT FROM AUTHOR]

Stalling of residential air conditioners (RACs) following a transient fault can delay the voltage recovery ranging from 3 to 20 seconds. This phenomenon is referred to as fault-induced delayed voltage recovery (FIDVR). Several aggregated RAC models have been presented to replicate the actual FIDVR events. However, they usually have two main drawbacks as: i) considering independent stalling voltage and stalling time for all RACs, ii) resulting in only two ultimate modes; either 100% stalled or 100% normal running. This paper amends the abovementioned shortcomings by proposing a simple and effective performance-based RAC model. The proposed model utilizes a simple explicit relation between the stalling voltage and its required time to stall the RAC, furthermore, it can stall a fraction of RACs based on the voltage dip characteristics. The experimental results support the proposed model and computer simulations employing the IEEE 118-bus test system and Iran's electricity grid reveal the effectiveness of the proposed model. [ABSTRACT FROM AUTHOR]

In this article, technical-economical investigation of heating and cooling loads in faculty of engineering of Arak University, Iran has been investigated. The traditional and modern conditioner systems such as CAV, VAV, fan coil systems (all three systems are tested with direct fired absorption chiller and screw chiller), VRF system, split system and evaporative cooling system (in total 9 different systems) are designed for this faculty and are compared technicallyeconomically. In this article, the costs of water, electricity and gas, purchase of systems and equipment, maintenance and repair of equipment of the examined systems are calculated and are compared with each other and then this work is done in different cooling loads, so that the results are not limited to the technical faculty of Arak university and can be used for all existing systems throughout the country. In the end, it is shown, that the evaporative cooling system has the lowest current and initial cost among the other systems. However, since this systems do not have the ability to determination of the amount of humidity and ideal temperature for the desired space cannot be considered as an ideal and standard system. Also it is shown, that the current and initial costs of compression chiller are less than of absorption chiller and VAV systems have the better performance than CAV and fan coil systems, and the VRF system, after the evaporative cooling system, has the lowest current and initial cost among the examined systems, especially the split system. Due to the intelligent and optimal control of this system, it can be selected as an ideal system. [ABSTRACT FROM AUTHOR]

This paper proposes a new hybrid state estimation (SE) model where the supervisory control and data acquisition (SCADA) and phasor measurement unit (PMU) measurements are decoupled. The proposed hybrid SE can effectively handle different accuracy levels of PMU and SCADA measurements which is a problem for conventional hybrid SEs due to increasing the condition number of SE gain matrix. In addition, the proposed hybrid SE model is fully compatible with PMU measurements, particularly current measurements, which increase the complexity of conventional hybrid SE formulation. The proposed hybrid SE model is tested on the IEEE 118-bus test system as well as on the real-world Iran’s power system. Moreover, the proposed hybrid SE is compared with conventional hybrid SE using a large number of scenarios modeling uncertain telemetry noises. The comparative results illustrate better performance of the proposed hybrid SE than conventional hybrid SE in terms of the gain matrix condition number, SE run time, and SE accuracy. [ABSTRACT FROM AUTHOR]

A multi-objective wind farm integration framework is proposed in this paper which considers the composite generation and reliability assessment and annualized operating and investment cost evaluation. An emission-controlled policy is adopted such that the amount of SOx and NOx decreases in line with renewable resource planning. Since the incorporation of large-scale distant wind farms is a problem of the multi-objective mixed-integer type with nonlinearities and non-convexities, this paper utilizes a fast elicit multi-objective Non-dominated Sorting Genetic Algorithm II (NSGA II) by probabilistic indices. It is noted that the impacts of the unavailability of the transmission system are modeled employing DC Optimal Power Flow (OPF) based on the incidence matrix together with the static security evaluation. Furthermore, in order to assess the performance of the suggested approach, the model is implemented on the Roy Billinton Test System (RBTS). Afterwards, distant wind farms integration into Iran's South-West Regional Grid (ISWRG) is studied. • Proposing a framework for distant wind farm integration. • Implementing an accurate model for risk evaluation based on of HL-II reliability calculation. • Reducing the computational burden by implementing virtual database. • Applying VDS-NSGA-II method to solve the proposed problem in an effective way. [ABSTRACT FROM AUTHOR]

• A new method based on the discrete energy separation algorithm presents to HIF and LIF detection in distribution system. • Simple implementation and low computational burden are main advantages of the method. • The method detects HIF and LIF from other disturbances with high detection accuracy and low detection time even in noisy condition. • The method has proper performance in detection of recorded real HIFs in distribution system. • CT saturation has no impact on the detection accuracy and time of the method in LIF detection. Due to the low fault current of high impedance fault (HIF), it is not recognized by overcurrent relays. Moreover, due to the similar characteristics of HIF and other disturbances like capacitor bank (CB) and non-linear load (NL) switching, detection of HIF is one of the main challenges in protection of distribution system. Furthermore, detection of low impedance fault (LIF) is important for protection system. In this paper, a new statistical method is proposed based on a discrete time separation algorithm of energy for detection of HIF and LIF from other disturbances to improve detection accuracy and time. The method consists of two main parts, the first one detects switching on/off the linear load, switching off the CB and switching off the NL from abnormal conditions, while the second part identifies the HIF and LIF from switching on the CB and switching on the NL. High detection speed, simple implementation, and low computational burden are advantages of the method. The method is tested on IEEE 13-node and IEEE 34-node distribution test systems, and a real feeder in Iran. Obtained results show that the high efficiency of the proposed method in detection of disturbances even in noisy conditions, with low detection time. [ABSTRACT FROM AUTHOR]

• A new stochastic mixed-integer linear programming (SMILP) model is proposed for power distribution system (PDS) resilience enhancement against extreme dust storms (EDSs). • Investment and operating costs under the EDS conditions are minimized considering uncertainties and PDS financial and operational constraints. • The proposed actions for PDS resilience enhancement include pre-and post-EDS actions. • Pre-and post-EDS actions are coordinated to minimize load shedding and system performance loss in the emergency conditions. • The effect of budget constraint on the planning results is evaluated and it is determined which measures will achieve the greatest improvement in PDS resilience at each budget level. Extreme dust storms (EDSs) are rare natural disasters, occurring with a higher rate of incidence and severity in recent years in coastal areas with humid climate. EDSs can hamper the operation of power distribution systems (PDSs) and other related urban infrastructures, and damage PDS insulation equipment. In this paper, a bi-level stochastic mixed-integer linear programming model is proposed for PDS resilience enhancement against EDSs. In the proposed model, the investment cost and total expected operating costs under the EDS conditions are minimized while considering uncertainties and PDS financial and operational constraints. The proposed actions for PDS resilience enhancement include pre-and post-EDS actions. Pre-EDS actions include simultaneous hardening of lines and substations, optimal placement of sectionalizing switches, and installation of emergency generators (EGs) in critical points. Post-EDS actions include damaged lines and substations repair, optimal network reconfiguration, power dispatch of EGs and optimal load shedding. The planning results at different budget levels show that coordinating pre-and post-event actions can reduce investment costs besides reducing operational costs. Implementation of the proposed model on the IEEE 33-bus test system and a large-scale PDS in Khuzestan province, a coastal province in southwestern Iran, confirms the efficiency of the proposed method for PDS resilience enhancement planning. [ABSTRACT FROM AUTHOR]

In Generation Expansion Planning (GEP), the power plants lifetime is one of the most important factors which to the best knowledge of the authors, has not been investigated in the literature. In this article, the power plants lifetime effect on GEP is investigated. In addition, the deep learning-based approaches are widely used for time series forecasting. Therefore, a new version of Long short-term memory (LSTM) networks known as Bi-directional LSTM (BLSTM) networks are used in this paper to forecast annual peak load of the power system. For carbon emissions, the cost of carbon is considered as the penalty of pollution in the objective function. The proposed approach is evaluated by a test network and then applied to Iran power system as a large-scale grid. The simulations by GAMS (General Algebraic Modeling System, Washington, DC, USA) software show that due to consideration of lifetime as a constraint, the total cost of the GEP problem decreases by 5.28% and 7.9% for the test system and Iran power system, respectively. [ABSTRACT FROM AUTHOR]

• Presenting a semi-decentralized framework for joint expansion planning of privately owned regional energy system and sub-transmission grid utilizing multi-agent systems. • Establishing a bi-stage decision-making process based on Stackelberg game to reach the interaction among agents for sub-transmission expansion planning. • Decision-making among players using a fuzzy satisfying and Max-Min method for finding Stackelberg Equilibrium (SE) point. Traditionally, a regional electric company (REC) should supply electricity demand of consumers at sub-transmission level in special geographic areas. As a promising alternative for traditional centralized planning, in this paper, a Stackelberg game approach is employed to solve the investment and operational expansion planning problems in the presence of privately owned Regional Energy Systems (RGESs) and multi-agent systems are used to ease the participation of private ownerships in planning model by preventing agents to disclose their private properties. The RGES's and the REC's agents are the active players of the proposed method and in the form of a semi-decentralized framework, the information exchange among them is fully decentralized. Also, an Independent Coordinating Agent (ICA) is centrally responsible for Stackelberg Nash equilibrium point extraction. Further, a bi-stage Stackelberg game approach is proposed for coupled expansion planning program of Sub-transmission network and privately owned RGESs. To validate the feasibility and efficacy of the suggested model, a modified electric sub-transmission system (located in Guilan Province, Islamic Republic of Iran) is employed as a realistic test case system for simulations. And, the obtained results of simulations by the proposed method are compared with conventional expansion planning of sub-transmission systems. [ABSTRACT FROM AUTHOR]

• Multi-objective framework for increasing the penetration of wind farms to the power grids. • An accurate MIP model for the capacity additions in the expansion planning problem. • Probabilistic model for solving the generation and transmission expansion planning problem. • Long-term planning problem in a centralized decision-making framework. Integrated transmission expansion planning (TEP) and generation expansion planning (GEP) with Wind Farms (WFs) is addressed in this paper. The optimal number of expanded lines, the optimal capacity of WFs installed capacity, and the optimal capacity of wind farms lines (WFLs) are determined through a new TEP optimization model. Furthermore, the optimum capacity additions including conventional generating units is obtained in the proposed model. The Benders decomposition approach is used for solving the optimization problem, including a master problem and two sub-problems with internal scenario analysis. In order to reduce the computational burden of the multi-year and multi-objective expansion planning problem, a multi-stage framework is presented in this paper. The uncertainties of wind speed and system demand along with contingency scenarios lead to a probabilistic optimization problem. Moreover, in the proposed model, the planning time horizon is divided into three predefined stages. This multi-stage approach is used to increase the proposed model accuracy in a power system with a high level of wind power penetration. Hence, in this paper a scenario-based probabilistic multi-stage model for transmission expansion planning is proposed, incorporating optimal WFs integration. It is recognized that high wind penetration increases the transmission expansion investment cost, but based on the reduction of the investment cost of conventional units, the total system cost will be smaller. This result emphasizes the main advantage of wind generating system over the conventional generating system. This planning methodology is applied to the modified IEEE 24-bus test system and simplified Iran 400-kV real system to show the feasibility of the proposed algorithm. [ABSTRACT FROM AUTHOR]

This paper proposes an optimal operational scheduling framework to integrate the distributed generators (DGs) in the distribution network. This framework is used to maximize the benefit of DG owner and distribution network operator (DNO). In this paper, two optimization model has been proposed to optimum emission and economic operation performance of distribution network in the presence of demand response program (DR). DR under time of use (TOU) pricing is utilized to promote both DG owner and DNO benefits from economic operation issue. The mixed-integer programming (MIP) is used to model a multi-objective problem in General Algebraic Modeling System (GAMS). Then, the problem is solved by employing weighted sum and fuzzy decision making methods. The obtained results reveal that due to positive implementation of DR program, dependency of the distribution network to the upstream network is decreased and load curve become smoother. The under study systems are IEEE 33-bus test system and 101-bus Khoy-Iran actual distribution system which compose electric vehicle parking lot (PL), battery storage, hydrogen storage system (HSS), and local dispatchable generators (LDG). • Optimal scheduling of HSS. • Benefit maximization of DG owner and DNO. • Employing TOU based DR program. • Implementing sum weighted method and fuzzy decision making method. [ABSTRACT FROM AUTHOR]

In order to facilitate the transformation of the existing generation and transmission networks' structure into a scalable and competitive grid structure, this paper introduced regional energy systems (RGESs) that have the role of aggregating distributed energy resources (DERs) and flexible loads. The economic justification for the expansion of sub-transmission networks in the presence of regional energy systems was also investigated. To achieve this goal, multi-criteria optimization solutions were employed to find techno-economic solutions. While solving the proposed multi-criteria optimization problem, a Pareto front was determined to show the tradeoff between the criteria examined. In addition, fuzzy satisfying and the max-min method were used for finding equilibrium point. In order to demonstrate the performance and effectiveness of the proposed model, a realistic sub-transmission system in Guilan Province, Iran, was used as a test system and the results were compared to those from a traditional sub-transmission expansion planning model. [ABSTRACT FROM AUTHOR]