The thesis reports the results of comprehensive studies carried out to explore the impact of midpoint FACTS Controllers (STATCOM and SVC) on the generator distance phase backup protection in order to identify important issues that protection engineers need to consider when designing and setting a generator protection system. In addition, practical, feasible and simple solutions to mitigate the adverse impact of midpoint FACTS Controllers on the generator distance phase backup protection are explored. The results of these studies show that midpoint FACTS Controllers have an adverse effect on the generator distance phase backup protection. This adverse effect, which can be in the form of underreach, overreach or a time delay, varies according to the fault type, fault location and generator loading. Moreover, it has been found that the adverse effect of the midpoint FACTS Controllers extends to affect the coordination between the generator distance phase backup protection and the generator steady-state overexcited capability limit. The Support Vector Machines classification technique is proposed as a replacement for the existing generator distance phase backup protection relay in order to alleviate potential problems. It has been demonstrated that this technique is a very promising solution, as it is fast, reliable and has a high performance efficiency. This will result in enhancing the coordination between the generator phase backup protection and the generator steady-state overexcited capability limit in the presence of midpoint FACTS Controllers. The thesis also presents the results of investigations carried out to explore the impact of the generator distance phase backup protection relay on the generator overexcitation thermal capability. The results of these investigations reveal that with the relay settings according to the current standards, the generator is over-protected and the generator distance phase backup protection relay restricts the generator overexcitation thermal capability during system disturbances. This restriction does not allow the supply of the maximum reactive power of the generating unit during such events. The restriction on the generator overexcitation thermal capability caused by the generator distance phase backup protection relay highlights the necessity to revise the relay settings. The proposed solution in this thesis is to reduce the generator distance phase backup protection relay reach in order to provide secure performance during system disturbances.

Many different Flexible AC Transmission System (FACTS) devices have been studied in recent years in order to control the flow of power through transmission lines and reduce the overall burden on the power grid. The net results of these devices are decreased utility costs, increased system stability, and improved system flexibility. The main issues with most currently available FACTS controllers are the high costs of installation, and operation. The Sen Transformer (ST) is a new FACTS device that decreases these costs by using relatively inexpensive and industry familiar transformer technology to independently control the active and reactive power in a transmission line.<p> This thesis introduces the first full transient model for the ST developed in an ElectroMagnetic Transients Program (EMTP) using a hybrid transformer modeling approach. This technique handles all the non-linearities of the core, including losses and saturation effects, as well as inter-phase coupling, and zero sequence effect with an attached topographically correct core model. This new model can be used in a variety of power system studies such as transient and dynamic simulations, and protection analysis. The flexibility of the hybid ST model allows for different core and winding configurations as well as response to very fast transients with little modification. Fault analysis studies are presented to showcase the capabilities of the transient ST model developed.<p> The first ST transient model using the Finite Element Analysis (FEA) technique is also created for comparison with the hybrid ST model. This method uses Maxwells equations, material non-linearities and coupled electric circuits to obtain a precise transient solution for the ST. There is good agreement between the two models in a test system for multiple types of fault scenarios. The hybrid ST model is therefore the preferred model to use for fault analysis since it reduces simulation time drastically when compared to the FEA ST model.<p> The hybrid ST model is then used to develop and test differential, and ground protection schemes that ensure device safety during faulted scenarios. The protection schemes are analyzed and compared with analogous Phase Angle Regulator (PAR) schemes that have been implemented for many years.

El ejercicio profesional del periodismo vive entre dos tensiones que parecen incompatibles: el deseo de una objetividad que parecería de otro mundo en su luminosidad sin mácula y la acusación de imposibilidad para mantener esa objetividad. Esta investigación traza, en primer lugar, la lógica que funciona en el interior del ejercicio de la información periodística (una filosofía de la información), y en segundo lugar, revisa algunas teorías de la información, especialmente las críticas con el ejercicio profesional, las que subrayan su supuesta perversidad congénita. Tras ese trabajo propedeutico la investigación desmonta, a la vez, tanto ese constructo lógico -imaginario ideal de la profesión- como las criticas injustas. La investigación propone entonces la hipótesis de la capacidad del períodismo de describir con veracidad aspectos parciales de la realidad, es decir, su capacidad de decir verdad. Y llega a la tesis de que, bajo determinadas condiciones epistémicas y deontológicas, el periodismo es un medio tan valioso como otros -en última instancia su método es, o debería ser, similar al de la ciencia- para plasmar hechos y realidades, es un método de conocimiento, una manera de la verdad, siempre que ésta no sea entendida como verdad absoluta, esencial o metafísica. / Tbe professional practice of journalism líes in between two tensions that seem incompatible: 1) wanting an objectivity that would seem from another world in its faultless luminosity, and 2) accusing on som ething to be impossible to keep tbat objectivity. Tbis research, firstly, draws the logic that works in the inside of the practice of journalist information (a philosophy of information), and secondly, it revises some theories of information,and secondly, it revises some theories of information, especially the reviews with the professional exercise, tbe ones which underline its supposed congenital depravity. After that preparatory work, the research falls into despair, at the same time, both that logical construct (imaginary ideal of the job) and the unfair criticism. The research proposes then the hypothesis of the ability of journalism to describe truthfully the partial aspects of reality, that is, its ability to tell the truth. And it gets to the conclusion that, under certain epistemic and deontological conditions, journalism is a means as worthy as others - in the last analysis, its method is, or should be, similar to the one of a science to reflect facts and realities. It is a means of knowledge, a way of truth as long as this is not understood as an absolute, essential or metaphysical truth.

Electricity systems are very complex systems and are composed of numerous transmission lines, generators and loads. The generating stations are generally far away from load centres and that may cause transmission line congestion and overloading. Series capacitive compensation is the most economical way to increase transmission capacity and improve transient stability of transmission grids. However, one of the impeding factors for the widespread use of series capacitive compensation is the potential risk of Subsynchronous Resonance (SSR). Subsynchronous Resonance is a phenomenon in which electrical power is exchanged with the generator shaft system in an increasing manner which may result in damage to the turbine generator shaft system. Therefore, mitigating SSR continues to be a subject of research and development aiming at developing effective SSR countermeasures.<p>This research work presents new methods of alleviating the SSR problem using a Static Synchronous Series Compensator (SSSC) and a Static Synchronous Compensator (STATCOM). These methods are based on using the SSSC and STATCOM to inject unbalanced series quadrature voltages and unbalanced shunt reactive currents in transmission line just after clearing faults. When the subsynchronous oscillations drive unsymmetrical phase currents, the developed electromagnetic torque will be lower than the condition when the three-phase currents are symmetrical. The unsymmetrical currents result in a lower coupling strength between the mechanical and the electrical system at asynchronous oscillations. Therefore, the energy exchange between the electrical and the mechanical systems at subsynchronous oscillations will be suppressed, thus, avoiding the build-up of torsional stresses on the generator shaft systems under subsynchronous resonance condition. The validity of proposed methods are demonstrated by time simulation results using the electromagnetic transient program EMTP-RV.

The thesis reports the results of comprehensive studies carried out to explore the impact of midpoint FACTS Controllers (STATCOM and SVC) on the generator distance phase backup protection in order to identify important issues that protection engineers need to consider when designing and setting a generator protection system. In addition, practical, feasible and simple solutions to mitigate the adverse impact of midpoint FACTS Controllers on the generator distance phase backup protection are explored. The results of these studies show that midpoint FACTS Controllers have an adverse effect on the generator distance phase backup protection. This adverse effect, which can be in the form of underreach, overreach or a time delay, varies according to the fault type, fault location and generator loading. Moreover, it has been found that the adverse effect of the midpoint FACTS Controllers extends to affect the coordination between the generator distance phase backup protection and the generator steady-state overexcited capability limit. The Support Vector Machines classification technique is proposed as a replacement for the existing generator distance phase backup protection relay in order to alleviate potential problems. It has been demonstrated that this technique is a very promising solution, as it is fast, reliable and has a high performance efficiency. This will result in enhancing the coordination between the generator phase backup protection and the generator steady-state overexcited capability limit in the presence of midpoint FACTS Controllers. The thesis also presents the results of investigations carried out to explore the impact of the generator distance phase backup protection relay on the generator overexcitation thermal capability. The results of these investigations reveal that with the relay settings according to the current standards, the generator is over-protected and the generator distance phase backup protection relay restricts the generator overexcitation thermal capability during system disturbances. This restriction does not allow the supply of the maximum reactive power of the generating unit during such events. The restriction on the generator overexcitation thermal capability caused by the generator distance phase backup protection relay highlights the necessity to revise the relay settings. The proposed solution in this thesis is to reduce the generator distance phase backup protection relay reach in order to provide secure performance during system disturbances.

Following by the signing of ECFA recently, the industrial environment is changed rapidly forcing many small and medium enterprises to face various kinds of internal and external challenges. They encounter the obstacles to advance their technical and producing system which is their weakness as well. In the earlier year, these enterprises was founded basing on the trusting relationship between the owner and the employees, and the working regulations, salary, and bounces were created according to their cooperating consensus. However, when their original mode of production could not catch up in time along with the growth of capacity, advance of the industry and expansion of market, the relationship has started to change. Hence, they tried to change the original structure by looking for transforming or through the organizational improvement in response to the upcoming crisis and challenges. Among these changes, the establishment and import of systematization has become the major pattern in present. This research is focused on a traditional machinery factory which produces non-standard products internationally hoping to create new experience inspired by the success in the past including introducing the new management mode and new strategy from the stage of contract signing, design to post service making the company on the invincible position. During the process of transforming, many relationship-oriented enterprises including the one discussed in this research are facing several different factors among clients vs. company, agency vs. company, company vs. suppliers, and company vs. employees and what influence will be caused due to the establishment of the new system is the main discussion in this research. Furthermore, whether the customized production is suitable for the new system? What kind of obsolete will the company encounter? Will there be any problem caused? Also, the research will discuss how to locate the most suitable method within all kinds of possible limiting factors through hard facts, dangerous half-truths & total nonsense and convert these knowhow into power to decrease all the impacts brought by the changes.

The objective of the research is to develop a cost-effective, dynamic grid controller called the controllable network transformer (CNT) that can be implemented by augmenting existing load tap changing (LTC) transformers with an AC-AC converter. The concept is based on using a fractionally rated direct AC-AC converter to control the power through an existing passive LTC. By using a modulation strategy based on virtual quadrature sources (VQS), it is possible to control both the magnitude and the phase angle of the output voltage of the CNT without having any inter-phase connections. The CNT architecture has many advantages over existing power flow controllers, like absence of low frequency storage, fractional converter rating, retro-fitting existing assets and independent per-phase operation making it potentially attractive for utility applications. The independent control of the magnitude and the phase angle of the output voltage allow independent real and reactive power flow control through the CNT-controlled line. In a meshed network with asymmetric network stresses this functionality can be used to redirect power from critically loaded assets to other relatively under-utilized parallel paths. The power flow controllability of CNT can thus be used to lower the overall cost of generation of power. The solid state switches in the CNT with fast response capability enable incorporation of various additional critical functionalities like grid fault ride through, bypassing internal faults and dynamic damping. This bouquet of features makes the CNT useful under both steady state and transient conditions without compromising the grid reliability.

This thesis has been performed in collaboration with Volvo Cars Engine in Skövde, Sweden and Zhangjia-kou, China in order to receive a bachelor degree in automation engineering from the University of Skövde. The project focuses on analyzing the capacity of a future production line by using discrete event simulation. The production line is built in two different discrete event simulation software, FACTS analyzer and Plant Simulation. The focus of the study will be to compare the output results from the two software in order to give recommendations for which software to use in similar cases. This is done in order for Volvo Cars Corporation to have as a basis for further work in similar cases. The aim of the work is to verify the planned capacity of the new production line and to perform a leadership study with Chinese engineers in order to find out how they view the Swedish leadership and how this can be adapted to China and the Chinese culture and give recommendations for future work. The results of the capacity analysis show that the goals of parts produced can be reached for both planned capacities but also that there are potential constraints that have been identified in the system. The results of the leadership study also show that the overall approach should be slightly adapted to be better suited for the Chinese culture. The comparison of the two simulation software suggests that FACTS Analyzer is suit-able to use when less complex logic or systems are represented, however when building more complex models consisting of more complex logic Plant Simulation is more suitable.

Sudarydami sandorius asmenys siekia tam tikro teisinio rezultato: sukurti naujas, pakeisti ar panaikinti turimas civilines teises ir pareigas. Laisva asmenų valia ir sutikimas su visomis konkretaus sandorio sąlygomis yra esminė kiekvieno sandorio galiojimo prielaida. Tačiau tai yra tik siekiamybė, kadangi praktikoje ne visuomet ir ne visi sandoriai sudaromi esant teisingai išreikštai šalių valiai dėl sandorio objekto, terminų, atlygintinumo, sandorio įvykdymo pobūdžio ar kitų būtinųjų sąlygų. Nors kiekviena demokratinė teisinė valstybė įstatymais ir kitais teisės aktais stengiasi užtikrinti sandorių bei tarp sandorio šalių susiklosčiusių civilinių teisinių santykių stabilumą, ji taip pat privalo nustatyti sąlygas, kuriomis šalis, sandoriu neišreiškusi tikrosios savo valios ar išreiškusi ją klaidingai, įgyja teisę visiškai ar iš dalies atsisakyti ir paties sandorio, ir iš jo kylančių teisių bei pareigų. Tiek civilinės teisės tradicijos valstybėse, tiek ir bendrosios teisės tradicijos valstybėse tarp tokių sandorio pripažinimo negaliojančiu pagrindų kaip apgaulė, prievarta, asmens neveiksnumas, įgaliojimų viršijimas bei kitų yra ir vienos ar abiejų sandorio šalių suklydimas. Kaip ir kitų sandorio pripažinimo negaliojančiu pagrindų atveju, taip ir esant suklydimui, teismo sprendimas priklauso ne tik nuo teisingo faktinių aplinkybių nustatymo ir įvertinimo, bet ir nuo tinkamo aktualių teisės normų išaiškinimo bei pritaikymo. Suklydimo doktriną ir jos sąsają su sandorių... [toliau žr. visą tekstą] / When entering into contracts persons expect some kind of legal result: either to create new civil rights and duties, or to change or withdraw those they already have. Free will of the persons and consent towards all provisions set out in a particular contract is the essence of the validity of that contract. However, it can only be considered to be an aim, whereas in practice not each and every contract is concluded having as a pre-condition correctly expressed will with regard to the object, terms, nature of execution or other material provisions of the contract. Even though each democratic judicial state is aiming at securing the stability of contracts, civil rights and duties of persons, it also has to determine rules when and under what conditions persons having mistakenly expressed their will are entitled to fully or partially rescind the contract as well as rights and duties arising out of it. Both, civil law countries and common law countries among such grounds as fraud, duress, incapability, entitling one to make the contract voidable, also have a ground called mistake, whether it be unilateral or mutual. Law with regard to doctrine of mistake is very complex and not always clear. Courts not just have to interpret and apply those unclear laws correctly, they also have to find the balance between two conflicting basic statutory principles: principle stating that “contract is valuable, therefore if there is a possibility not to declare it invalid, it should be left as... [to full text]

Teisė į saviraiškos laisvę suteikia žmogui galimybę reikšti savo turimus įsitikinimus ir idėjas. Nors šiai teisei suteikiama ypatinga teisinė apsauga tiek Lietuvos, tiek tarptautiniuose teisiniuose dokumentuose, ji nėra absoliuti ir gali būti ribojama, siekiant apsaugoti kitų žmonių teises ir laisves bei kitus svarbius interesus. Pusiausvyros suradimas tarp kitų įstatymų saugomų vertybių ir nuomonės reiškimos laisvės yra svarbus kiekvienos valstybės teisinės sistemos uždavinys. Šio uždavinio įgyvendinime yra svarbu nustatyti tam tikrų nuomonės reiškimo laisvės sąlygų ribojimo būtinumą demokratinėje visuomenėje. Dažnai žmonės viešai reikšdami savo nuomonę pateikia tam tikrų faktų ir dalykų vertinimą, bet savo vertinimui nepateikia įrodymų, faktų, kad kiti žmonės galėtų įsitikinti jų vertinimų teisingumu. Jeigu tokia nuomonė nepažeidžia kitų įstatymuose saugomų vertybių, ji yra leidžiama. Nuomonių ir idėjų pliuralizmo egzistavimas visuomenėje yra ypač svarbus išreiškiant politinę kritiką, todėl nuomonių ribojimas, reikalaujant jas pagrįsti faktais, kliudytų išlaikyti demokratijos tęstinumą, nes žmonės vengtų reikšti savo nuomonę svarbiais visuomeninio gyvenimo klausimais. Nuomonės yra subjektyvūs vertinimai ir kurioms, skirtingai nei žiniai, nėra taikomas tiesos kriterijus. Kadangi nuomonės yra nepatikrinamos ir nuomonių įrodinėti nėra privaloma, negalima reikalauti ir jų paneigimo. Reikalavimas nuomonę pagrįsti faktais ar kitais įrodymais būtų saviraiškos laisvės suvaržymas... [toliau žr. visą tekstą] / Freedom of expression is one of the fundamental human rights. People can express themselves not only in private, but also in public and social life. This right is guaranteed in the constitutions of many states, international human rights and other legal documents. Exceptional legal protection for freedom of expression is justified because of it’s importance for maintaining stability of democracy. One of the main element of freedom of expression is the right to hold opinions without interference. The right to hold opinions allows people to express their views, beliefs and ideas verbally or in writing. Journalists, politicians and other society members can realize this right especially in the media, where their opinions reach many people. It is important that person who realizes his/her right in public to hold opinions, would not violate the rights of other people. When people express their opinions in public, they mostly express value – judgements about some facts. Often they don’t explain, why do they think so, don’t give some facts that could prove truth of their statements. Can always be allowed the opinion that is not grounded on facts? The main goal of this work is to establish, weather the human right to freedom of expression allows in public to express opinion that is not grounded on facts. Freedom of expression, as the right to hold opinions, is not absolute. Because of the conflict between the right to hold opinions and other rights, the right to hold opinions can be... [to full text]