Investigation of domestic level EV chargers in the Distribution Network: An Assessment and mitigation solution

This research focuses on the electrification of the transport sector. Such electrification could potentially pose challenges to the distribution system operator (DSO) in terms of reliability, power quality and cost-effective implementation. This thesis contributes to both, an Electrical Vehicle (EV) load demand profiling and advanced use of reactive power compensation (D-STATCOM) to facilitate flexible and secure network operation. The main aim of this research is to investigate the planning and operation of low voltage distribution networks (LVDN) with increasing electrical vehicles (EVs) proliferation and the effects of higher demand charging systems. This work is based on two different independent strands of research. Firstly, the thesis illustrates how the flexibility and composition of aggregated EVs demand can be obtained with very limited information available. Once the composition of demand is available, future energy scenarios are analysed in respect to the impact of higher EVs charging rates on single phase connections at LV distribution network level. A novel planning model based on energy scenario simulations suitable for the utilization of existing assets is developed. The proposed framework can provide probabilistic risk assessment of power quality (PQ) variations that may arise due to the proliferation of significant numbers of EVs chargers. Monte Carlo (MC) based simulation is applied in this regard. This probabilistic approach is used to estimate the likely impact of EVs chargers against the extreme-case scenarios. Secondly, in relation to increased EVs penetration, dynamic reactive power reserve management through network voltage control is considered. In this regard, a generic distribution static synchronous compensator (D-STATCOM) model is adapted to achieve network voltage stability. The main emphasis is on a generic D-STATCOM modelling technique, where each individual EV charging is considered through a probability density function that is inclusive of dynamic D-STATCOM support. It demonstrates how optimal techniques can consider the demand flexibility at each bus to meet the requirement of network operator while maintaining the relevant steady state and/or dynamic performance indicators (voltage level) of the network. The results show that reactive power compensation through D-STATCOM, in the context of EVs integration, can provide continuous voltage support and thereby facilitate 90% penetration of network customers with EV connections at a normal EV charging rate (3.68 kW). The results are improved by using optimal power flow. The results suggest, if fast charging (up to 11 kW) is employed, up to 50% of network EV customers can be accommodated by utilising the optimal planning approach. During the case study, it is observed that the transformer loading is increased significantly in the presence of D-STATCOM. The transformer loading reaches approximately up to 300%, in one of the contingencies at 11 kW EV charging, so transformer upgrading is still required. Three-phase connected DSTATCOM is normally used by the DSO to control power quality issues in the network. Although, to maintain voltage level at each individual phase with three-phase connected device is not possible. So, single-phase connected D-STATCOM is used to control the voltage at each individual phase. Single-phase connected D-STATCOM is able maintain the voltage level at each individual phase at 1 p.u. This research will be of interest to the DSO, as it will provide an insight to the issues associated with higher penetration of EV chargers, present in the realization of a sustainable transport electrification agenda

The Potential for Power Quality Problem Mitigation Through STATCOM

Consideration of spatial and temporal diversity of EV charging demand has been demonstrated to reduce the estimating impacts on the distribution networks. The data formulation is based on impact studies of Electrical vehicles (EV s) on distribution networks. It is suggested that Distribution System Operator (DSO) could benefit for new innovation/advancement in the market (BESS-STATCOM) in a way that makes networks more reliable/robust, In this regard such innovation creates more opportunities for demand side management, reduces planning uncertainties associated with stochastic nature of EV charging and makes space for demand side management. This work considers probabilistic load flow in a representative unbalanced distribution network and through Monte Carlo simulation increased the hosting capacity for DG/EV is considered in an Irish/UK context. Furthermore, this paper considers the potential for a distribution network deployed STATCOM in supporting EV penetration, while maintaining appropriate power quality (voltage) standards. To reduce the computation burden of Monte Carlo simulation an alternative (novel but simple) method is applied. In terms of the Irish/UK DSO perspective, this work will help to increase the hosting capacity of DG/EV without breaching power quality limits

Impact Assessment of High-Power Domestic EV Charging Proliferation of a Distribution Network

Transport electrification is becoming the mainstream as a means to improve efficiency, performance, andsustainability of transportation systems. Electrical vehicles (EVs) can help to de-carbonise the environment, but a downside isthe technical issues presented to the low-voltage distribution network. To quantify the stochastic nature of transport-affectedelectrification, probabilistic load flow is employed. Monte Carlo-based simulation is applied to accommodate the probabilisticuncertainties associated with variable EV charging patterns. This study considers high-power charging (up to 11 kW) at thedomestic level while monitoring power quality variations (voltage drop, voltage unbalance factor, voltage sag) standards. Thiswork focuses on the Irish and UK, distribution system operator\u27s–transmission system operator\u27s perspectives, as it will help toidentify the likely impacts due to high-EV charger proliferation at household locations. The results indicate that if a 3.68 kWcharger is used at the domestic level, it is possible for 40% of total household consumers to connect EVs directly to thedistribution network without any power quality breaches. Furthermore, the proliferation of EV can be increased up to 100% ifconstrained to the start, and middle portions of the network (relative to the feeder substation transformer). For higher chargercapacities (up to 11 kW), a bottleneck is presented regarding a resultant voltage unbalance factor

Ethical Considerations Surrounding Vaccine Development During A Public Health Crisis

Epidemics and Pandemics have been plaguing mankind since many centuries, and are a cause of major healthcare expense in modern times. The novel coronavirus pandemic of 2019-2020 spread worldwide faster than many previous pandemics, including EBOLA in 2017. Although personal protective equipment, and social distancing slowed the outbreak, a vaccine is needed to ensure global immunization and to stop this deadly outbreak. Developing a vaccine in times of a public health crisis comes with a lot of ethical considerations, including overlooking proper informed consent, the issue of using placebo in control arm of trials, extended timelines of development of vaccines, randomized placebo control trial of secondary vaccine once the first vaccine is approved, and utilizing vulnerable population for trials. These issues are often overlooked due to the urgency of the situation, and the need of developing a cure/vaccine can lead to potential oversight of many regulations. We discuss some of these issues related to vaccine development in a pandemic situation in this commentary paper. We also discuss some of the arguments supporting a secondary vaccine development such as logistical/economic issue, better efficacy, and the conditions of Equipoise

Mechanism of the antidiabetic action of Nigella sativa and Thymoquinone: a review

IntroductionLong used in traditional medicine, Nigella sativa (NS; Ranunculaceae) has shown significant efficacy as an adjuvant therapy for diabetes mellitus (DM) management by improving glucose tolerance, decreasing hepatic gluconeogenesis, normalizing blood sugar and lipid imbalance, and stimulating insulin secretion from pancreatic cells. In this review, the pharmacological and pharmacokinetic properties of NS as a herbal diabetes medication are examined in depth, demonstrating how it counteracts oxidative stress and the onset and progression of DM.MethodsThis literature review drew on databases such as Google Scholar and PubMed and various gray literature sources using search terms like the etiology of diabetes, conventional versus herbal therapy, subclinical pharmacology, pharmacokinetics, physiology, behavior, and clinical outcomes.ResultsThe efficiency and safety of NS in diabetes, notably its thymoquinone (TQ) rich volatile oil, have drawn great attention from researchers in recent years; the specific therapeutic dose has eluded determination so far. TQ has anti-diabetic, anti-inflammatory, antioxidant, and immunomodulatory properties but has not proved druggable. DM’s intimate link with oxidative stress, makes NS therapy relevant since it is a potent antioxidant that energizes the cell’s endogenous arsenal of antioxidant enzymes. NS attenuates insulin resistance, enhances insulin signaling, suppresses cyclooxygenase-2, upregulates insulin-like growth factor-1, and prevents endothelial dysfunction in DM.ConclusionThe interaction of NS with mainstream drugs, gut microbiota, and probiotics opens new possibilities for innovative therapies. Despite its strong potential to treat DM, NS and TQ must be examined in more inclusive clinical studies targeting underrepresented patient populations

Role of reactive power (STATCOM) in the planning of distribution network with higher EV charging level

In recent years, new trends in electrification of the transport sector have been a major concern for distribution grid operators. New types of flexible, uncontrollable loads, such as EV, influence the reliability of distribution networks. This work is related to the distribution system planning framework, with a particular focus on uncoordinated flexible EV loads. The main focus is the enhancement of the hosting capacity of EVs on distribution networks, while maintaining power quality (especially voltage magnitude and voltage unbalance), which is ultimately a pre-requisite for increasing prosumer engagement. Several EV charging scenarios, in the context of UK/Irish distribution networks with increased penetration of EV prosumers are considered. The results show that reactive power compensation through STATCOM, in the context of EV integration, can provide continuous voltage support and thereby facilitate 90% penetration of network customer EV connections at a normal EV charging rate (3.68 kW). If fast charging (up to 11 kW) is employed, \u3c30% of network EV customers can be accommodated due to bottlenecks presented by the substation transformer loading

Reactive Power Control for Smarter (Urban) Distribution Network Management With Increasing Integration of Renewable Prosumers

Smart cities need to deliver reliable electric energy while utilizing every renewable energy source available in a sustainable manner. Increasing renewable electricity capacity, through Distributed Generation (DG) such as small wind and PV generation, causes difficulties for the distribution network operator (DNO) in sustaining adequate and appropriate power quality across the network. The positive impacts provided by such energy sources can be undermined by voltage increases and voltage balance issues. To overcome these problems, urban distribution networks need to transform ideally into smarter energy networks that can deliver renewable electricity locally, predictably and in a controllable and optimized manner. The research presented here is based on electricity network simulation in an urban context. The main focus is the hosting capacity enhancement of distribution networks, while maintaining power quality, which is ultimately a pre-requisite for increasing prosumer engagement. In this regard, a test-bed representation of a 4-wire low-voltage section of distribution network in Dublin, Ireland is developed in DIgSILENT Power Factory. Several scenarios that consider increasing penetration of renewable prosumers in a smart electricity network context are presented. The results show that STATCOM, in the context of increasing DG integration, can provide continuous voltage support, by supplying or absorbing reactive power and thereby facilitating increased renewable DG contributions for a smarter, greener network

Evaluation of the probiotic and postbiotic potential of lactic acid bacteria from artisanal dairy products against pathogens

Introduction: Probiotic and postbiotic potential of thirty-two strains of lactic acid bacteria (LAB), obtained earlier from artisanal dairy sources in Pakistan, have been investigated against major multi-drug resistant (MDR) and food borne pathogenic bacteria. Methodology: LAB strains were identified by 16S rRNA gene sequencing and their antibacterial activity was assessed by the microdilution method. Four LAB isolates, Weissella confusa PL6, Enterococcus faecium PL7, and Lactobacillus delbrueckii PL11 and PL13 were shortlisted. Their ability to degrade lactose and safety for human consumption in terms of hemolysis and antibiotic susceptibility were assessed in vitro. The antibacterial components in the cell-free supernatants (CFSs) of isolate cultures were characterized biochemically by HPLC. Results: Acid neutralization but not protease treatment abolished the antibacterial activity of CFSs. Lactic, acetic and propionic acids were the main acids in the CFSs, and acid production peaked in the stationary phase of growth. The antibacterial activity of the LAB cultures resulted from secretion of organic acids that lowered the pH. The strains exhibited variable ability to degrade lactose and were non-hemolytic and susceptible to the most common antibiotics. Conclusions: These LAB strains are probiotic candidates for further investigation of their postbiotic role in naturally preserving processed foods and for attenuation of lactose intolerance.Peer reviewe

Generation of lactose and protease positive probiotic Lacticaseibacillus rhamnosus GG by conjugation with Lactococcus lactis NCDO 712

Lacticaseibacillus rhamnosus GG (LGG) is the most studied probiotic bacterium in the world. It is used as a probiotic supplement in many foods, including various dairy products. However, LGG grows poorly in milk, as it neither metabolizes the main milk carbohydrate lactose nor degrades the major milk protein casein effectively. In this study, we made L rhamnosus GG lactose and protease positive by conjugation with the dairy Lactococcus lactis strain NCDO 712 carrying the lactose-protease plasmid pLP712. A lactose-hydrolyzing transconjugant colony was obtained on agar containing lactose as the sole source of carbohydrates. By microscopic analysis and PCR with LGG- and pLP712-specific primers, the transconjugant was confirmed to have originated from LGG and to carry the plasmid pLP712. The transconjugant was named L. rhamnosus LAB49. The isolation of plasmids revealed that not only pLP712 but also other plasmids had been transferred from L lactis into LGG during conjugation. With plasmid-specific PCR primers, four additional lactococcal plasmids were detected in LAB49. Proteolytic activity assay and SDS-PAGE analysis verified that L rhamnosus LAB49 effectively degraded beta-casein. In contrast to its parental strain, LGG, the ability of LAB49 to metabolize lactose and degrade casein enabled strong and fast growth in milk. As strains with new properties made by conjugation are not regarded as genetically modified organisms (GM05), L. rhamnosus LAB49 could be beneficial in dairy fermentations as a probiotic starter culture. IMPORTANCE Probiotic strain Lacticaseibacillus rhamnosus GG (LGG) is widely sold on the market as a probiotic or added as a supplement in dairy foods because of its benefits in human health. However, due to the deficiency of lactose and casein utilization, LGG does not grow well in milk. On the other hand, lactose intolerance and cow's milk protein allergy are the two major problems related to milk consumption. One option to help with these two conditions is the use of probiotic or lactose- and casein-hydrolyzing bacteria in dairy products. The purpose of this study was to equip LGG with lactose/casein-hydrolyzing ability by bacterial conjugation. As a result, we generated a non-GMO LGG derivative with improved properties and better growth in milk.Peer reviewe