Load Flow Analysis and Optimization for Solar PV Integration in Power Systems

The International Institute of Knowledge Innovation and Invention (IIKII) is an institute that promotes the exchange of innovations and inventions, and establishes a communication platform for international innovations and researches. In 2019, IIKII cooperated with the Institute of Electrical and Electronics Engineers (IEEE) Tainan Section Sensors Council to hold IEEE conferences such as IEEE ICIASE 2019, IEEE ECBIOS 2019, IEEE ICKII 2019, ICUSA-GAME 2019, and IEEE ECICE 2019. This Special Issue entitled “Selected Papers from IIKII 2019 conferences” aims to select excellent papers from IIKII 2019 conferences, including symmetry in physics, chemistry, biology, mathematics, and computer science, etc. It selected 21 excellent papers from 750 papers presented in IIKII 2019 conferences on the topic of symmetry. The main goals of this Special Issue are to encourage scientists to publish their experimental and theoretical results in as much detail as possible, and to discover new scientific knowledge relevant to the topic of symmetry.

This paper presents a feature comparison between the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) Release 8 and Institute of Electrical and Electronics Engineers (IEEE) 802.16m and preliminary system performance comparison. As Orthogonal Frequency Division Multiple Access (OFDMA) mobile broadband air interfaces, LTE and IEEE 802.16m are both International Mobile Telecommunications-Advanced (IMT-Advanced) technologies. LTE and IEEE 802.16m, which both make use of Multiple-Input Multiple-Output (MIMO) channels, have their own features and advantages. This paper compares some features between LTE and IEEE 802.16m in terms of frame structure, effective bandwidth, Hybrid Automatic Retransmission Request (HARQ) and Modulation and Coding Scheme (MCS), which is a valuable replenishment to the former work. The system simulation results show that LTE and IEEE 802.16m achieve similar performance although they are different communication evolution systems from different specification work groups.

As part of the Very High Speed Optical Networks (VHSON) Demonstration Program, a simulator has been developed. The Scalable Coherent Interface Network Interface Functional Simulator (SCINIFS) addresses the Institute of Electrical and Electronic Engineers (IEEE) standard 1596-1992 for the Scalable Coherent Interface (SCI). In addition, SCINIFS addresses the evolving work of IEEE project P1596.6, entitled SCI Real-Time (SCI/RT). The SCI/RT project addresses extensions to IEEE Standard 1596 that seek to enhance SCI's utility for real-time fault-tolerant computing applications. SCINIFS addresses the functional behavior and performance of SCI/RT nodes when connected in a ring. The development of the simulator, early results and future work to model SCI switches are described.

This Innovative Practice full paper presents a software system which purpose is to be used to compose online laboratory experiences.Online Laboratories have improved their reliability and interoperability thanks to innovative developments proposed in recent years. New companies in this area have proposed novel interaction mechanisms such as the inclusion of immersive graphic user interfaces as well as the possibilities for access laboratory experiments as a service, having the alternative of just paying for the laboratory services demanded, for an specific class or for individual users. In terms of technology it is now possible to have multiple laboratory instances running from a single laboratory infrastructure or laboratory station. In terms of standardization, big efforts have been made by the Institute of Electrical and Electronics Engineers (IEEE) and the community of Online Laboratories to release in 2019 the first standard 18762019 - IEEE Standard for Networked Smart Learning Objects for Online Laboratories.The software system presented in this work uses a set of available resources including virtual laboratories (simulation based), local laboratory equipment, remote laboratories, laboratory activities, assessment definition and learning content (text, audio, video, etc). The system provides to the users a friendly set of tools to compose their laboratory experiences, following the IEEE 1876-2019 standard definition. The output composed laboratory experiment is saved as a Smart Laboratory Learning Object (SLLO) including mechanisms to be self-adaptable according to variables such as laboratory activities difficulty level, user previous results on the same or similar laboratory activities, and user expertise in the topic (determined based on information retrieved from the Learning Management System LMS).

This study investigates the effects of voltage and reactive power constraints on composite system reliability indices. Four indices have been used to assess the sensitivity of load curtailments to voltage and reactive power constraints. Furthermore, expressions to evaluate the sensitivity of the severity indices with respect to the voltage and reactive power constraints have been developed. Extensive simulations on the Institute of Electrical and Electronics Engineers (IEEE) reliability test system based on the AC power flow model were carried out to correlate the violations of these limits and the loading level of the system. A non‐linear, AC power flow‐based model has been used to accurately represent system redispatch. A state space reduction technique has been utilised to reduce the computation time. A comparison between redispatch models using AC and DC power flow has been provided to illustrate the benefits of the more accurate AC flow model and to investigate the effects of the voltage and reactive power constraints on reliability indices.

The integration of photovoltaic (PV) arrays to the power grid has continued to increase globally. Large PV array installations in the order of 100s of megawatt have already been installed. One of such large PV array installations is the Topaz PV array with an installed capacity of 500MW. With the increasing penetration of PV arrays, it is important to develop an accurate model for PV arrays. Such model will aid in performing state estimation, condition monitoring, load flow analysis, and other analytical studies. Several models for the PV module have been proposed in various publications. However, these models are written in a form that is effective for analyzing the PV module as an individual device. To analyze the PV array in an integrated power system, the form of the PV array model needs to be modified. This modification enables the establishment of connectivity between power system devices, and the definition of the admittance between the buses of the power system network. Consequently, computations such as load flow analysis and state estimation can be performed seamlessly. In this paper, a novel method for modeling a two-diode PV module is proposed. This model applies a scaling factor to the Taylor series expansion of the PV array model exponential terms. Next, the higher order terms of series expansion is reduced to at most second order terms using quadratization technique. This modeling method can also be applied to other PV array models, such as the one-diode and three-diode models. The form of the proposed PV array model enables seamless simulation of the PV array system in an integrated power system network.

In the last decade, there has been a tremendous growth in the field of grid-tied Photovoltaic (PV) generating plants in INDIA. With the recent government subsidies and reduction in the panel prices, the generation capacity has increased from a few kilowatts to hundreds of Mega-Watts. This rapid escalation in the penetration level on the grid has increased the utility companies’ concerns about its impact on the power quality of the system.In the current scenario, the penetration levels of the Photovoltaic generating in INDIA is very low to create any kind of significant power quality issues on the grid, however, power quality issues such as current harmonics and power factor have been identified in some cases. But with the increase in the penetration levels of PV generator on the grid, it may start affecting the overall power quality of the system. Power system stability and security issues, voltage variation (i.e. sag & swell), reverse power flow, power factor, and harmonics are the major power quality issues that may arise due to increased PV penetration. This paper gives an overall review of different power quality issues that may arise due to the increased penetration level of a PV generator on the grid.

John Vig, one of the candidates for president of the IEEE (Institute of Electrical and Electronics Engineers), supports embargoed OA. From his campaign page on OA: The page includes comments from IEEE members and Vig's replies. Vince Rosati asked how Vig would prevent "a serious loss [of revenue] to IEEE".

Now that the market for electrical apparatus has become global, there are efforts underway to compare standards with an intent to harmonize these standards. The Institute of Electrical and Electronics Engineers (IEEE) has made strides in this area. Specifically, the Electric Machinery Committee (EMC) of the IEEE Power Engineering Society is at the forefront of the IEEE harmonization effort. This paper gives some historical background and summarizes the details of this effort.

Purpose The purpose of this paper is to assess the efficacy of the Institute of Electrical and Electronics Engineers (IEEE) Xplore digital library search engine to return relevant materials on information visualization pedagogy literature and to recommend search strategies to assist the digital library academic readership improve the efficacy of their search tasks. Furthermore, the results are of interest to general readers using similar digital repositories. Design/methodology/approach An initial scoping review using EBSCO Discovery services returned the number and accessibility of sources and publications-based various Boolean searches. A revised search strategy focused the search to IEEE publications as the primary source of visualization research. A corpus of keywords were extracted from the 44 relevant articles and analyzed for relevance, keyword trends and contexts of use. Findings Keyword analysis results show visualization education research is confounded by several information retrieval issues: relevancy, incomplete taxonomy, non-standard lexicon, diverse disciplines and under-representation. Recommendations include: search strategies, alternative digital collections, a potential opportunity for research in information visualization pedagogy to address this gap in an emerging field and the need for more effective interactive tools to assist with keyword selection. Research limitations/implications The study focused on the IEEE publications as the primary source of visualization research. Practical implications A repository of visualization education research that is easily findable and relevant benefits both faculty using information visualization in their teaching and academics whose work must be disseminated to the broadest audience. Strategic keyword selection, interactive keyword tools or more robust thesaurus will enable IEEE Xplore digital library users to optimize their interaction with the system. Furthermore, results suggest a need for more research in information visualization pedagogy. Originality/value This is the only study to uniquely assess the efficacy of the IEEE Xplore digital library database system to retrieve relevant visualization education literature based on keyword search.

Over the past several years a growing focus on improved electrical safety has arisen. A better understanding of both electrical shock and arc flash hazards faced by personnel working on or near energized equipment has led to consensus standards such as the NFPA-70E. These standards deal primarily with safe work practices - designed to identify and quantify the hazard, then assure that personnel are clothed with appropriate personal protective equipment (PPE) to reduce the risk. Consensus opinion among safety experts is that the best method to reduce the risk of injury is by designing the hazards out. The next frontier in reducing electrical injuries will arise from improved designs of electrical products which mitigate hazards by design. One primary product area of interest is the low-voltage motor control center used for control of motors rated 1000 volts and below. In process applications such as cement, pulp and paper and petroleum and chemical plants, maintenance personnel often find it necessary to work on, or near, energized motor control centers while performing maintenance and operational activities. This paper will review work in progress by the Institute of Electrical and Electronics Engineers (IEEE) Working Group 1683 ldquoStandard for Motor Control Centers Rated up to 1000 volts with Requirements Intended to Reduce Injuriesrdquo Working Group. This group was initially formed by the IEEE Industry Applications Society Petroleum and Chemical Industry Committee and is working on ideas to improve the functional design and test requirements for motor control centers rated up to 1000 volts ac 50/60 Hz with specified safety and reliability features. The paper will briefly review the emerging standard and advise engineers that are interested in how to get involved to offer inputs for improving the standard. Information on new safety based low-voltage motor control center designs that have been recently introduced by several manufacturers will be reviewed. The review will show how the industry is responding to the product need articulated by the user community and the IEEE 1683 Working Group for product safety by design.

Numerical calculations of exposure to magnetic field of operators of suspended hand-operated resistance welding guns were performed using the own homogeneous, flexible human body models CIOP-MAN of the 95th and 5th percentile of adult men dimensions (185 and 164 cm in height), in 16 exposure situations with various postures of operator - typical for automotive factory. An assessment concerned calculated values of an induced electric field (E in ) in the brain and the heart - according to the ICNIRP (International Commission on Non-Ionizing Radiation Protection, 2010) and the IEEE (Institute of Electrical and Electronics Engineers, 2002). The results show applicability of flexible human body models in exposure evaluation based on E in values, even homogeneous. The values of E in in the brain and the heart are up to 34% higher when calculated following ICNIRP requirements than the values calculated following the IEEE method. The values of a welding current producing a B-field in the heart area of 100 µT/50Hz (i.e. the exposure limit for cardiac pacemakers users provided by ACGIH (American Conference of Governmental Industrial Hygienists, 2016) and CENELEC standard (European Committee for Electrotechnical Standardization)) are in the range of 0.43–1.6 kA, which is significantly lower than the typical current used in the industry (5–15 kA). Cardiac pacemaker users should not operate welding guns, as a result of the individual risk assessment required by the European directive on workers' protection (Directive 2013/35/EU).

Economic development relies on access to electrical energy, which is crucial for society’s growth. However, power shortages are challenging due to non-renewable energy depletion, unregulated use, and a lack of new energy sources. Ethiopia’s Debre Markos distribution network experiences over 800 h of power outages annually, causing financial losses and resource waste on diesel generators (DGs) for backup use. To tackle these concerns, the present study suggests a hybrid power generation system, which combines solar and biogas resources, and integrates Superconducting Magnetic Energy Storage (SMES) and Pumped Hydro Energy Storage (PHES) technologies into the system. The study also thoroughly analyzes the current and anticipated demand connected to the distribution network using a backward/forward sweep load flow analysis method. The results indicate that the total power loss has reached its absolute maximum, and the voltage profiles of the networks have dropped below the minimal numerical values recommended by the Institute of Electrical and Electronics Engineers (IEEE) standards (i.e., 0.95–1.025 p.u.). After reviewing the current distribution network’s operation, additional steps were taken to improve its effectiveness, using metaheuristic optimization techniques to account for various objective functions and constraints. In the results section, it is demonstrated that the whale optimization algorithm (WOA) outperforms other metaheuristic optimization techniques across three important objective functions: financial, reliability, and greenhouse gas (GHG) emissions. This comparison is based on the capability of the natural selection whale optimization algorithm (NSWOA) to achieve the best possible values for four significant metrics: Cost of Energy (COE), Net Present Cost (NPC), Loss of Power Supply Probability (LPSP), and GHG Emissions. The NSWOA achieved optimal values for these metrics, namely 0.0812 €/kWh, 3.0017 × 106 €, 0.00875, and 7.3679 × 106 kg reduced, respectively. This is attributable to their thorough economic, reliability, and environmental evaluation. Finally, the forward/backward sweep load flow analysis employed during the proposed system’s integration significantly reduced the impact of new energy resources on the distribution network. This was evident in the reduction of total power losses from 470.78 to 18.54 kW and voltage deviation from 6.95 to 0.35 p.u., as well as the voltage profile of the distribution system being swung between 1 and 1.0234 p.u., which now comply with the standards set by the IEEE. Besides, a comparison of the cost and GHG emission efficiency of the proposed hybrid system with existing (grid + DGs) and alternative (only DGs) scenarios was done. The findings showed that, among the scenarios examined, the proposed system is the most economical and produces the least amount of GHG emissions.

SUMMARY Wildfires are natural phenomena that play a crucial role in many forest and grassland ecosystems. Under favorable conditions, that is, extreme heat, availability of fuel, and high winds, they may spread beyond control and approach city limits. Power lines are vulnerable to wildfires in their vicinity, mainly because of increased conductor temperatures as a result of ambient temperature rising. This may lead to conductor annealing and/or increased sag. A violation of safety clearances of the lines could in turn lead to possible flashovers and onset of cascading failures. To address the situation, the operator may dynamically alter the ratings of the lines in the affected areas in order to reduce the flow of current through them, thereby assisting with conductor cooling. However, with reduced line capacities, the utility may not be able to supply all the loads from the main substation anymore, which may increase the risk of unserved load and load shedding. A solution is put forth in this paper that enables the system operator to dispatch distributed generators, demand responsive loads, and microgrids in order to supply loads under such emergency conditions. Because of the uncertain spread/severity of wildfires, the problem is stochastic in nature and is therefore modeled as two-stage stochastic optimization. First-stage variables determine the generation capacity to be purchased before the onset of the event, while second stage variables represent generation dispatch commands. The efficiency of the proposed solution is verified on a modified version of the Institute of Electrical and Electronics Engineers (IEEE) 123-bus test system. Copyright © 2014 John Wiley & Sons, Ltd.

Transactive Demand Response Operation at the Grid Edge using the IEEE 2030.5 Standard