...Stability of Power Systems Student’s Name The Name of the Class (Course) Professor (Tutor) The Name of the School (University) The City and State where it is located The Date Date of Submission Stability of Power Systems Power systems are studied under the branch of engineering known as power (systems) engineering. The subfield is concerned with the study of how electric power is generated, transmitted, distributed, and utilized. It also analyzes the electrical and electronics devices and gadgets that are connected to the power systems to assist in their functioning. Such devices include motors, transformers, and generators. Such devices offer optimal functionality when they are used under the right conditions and when they are stable. Stability is of critical importance to power systems. As such, this essay describes some of the fundamental concepts of the stability of power systems. It also highlights how balance is achieved in a synchronous generator. A system is said to be stable if it can regain its normal equilibrium state after an imposed disturbance is removed. Power system stability is referenced from a particular initial operating condition. As such, a system is said to be stable if the opposing forces within it are balanced and at a perfect equilibrium. Instability is caused by imbalance sustained when the opposing forces are not equal. The resulting disturbance causes instability within the power system (Grigsby 2012, p. 10). ...
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...alarming rate but the running demand of power is ahead of its supply. More the demand more generation. Due to increase generation, synchronism between different parts of power system has become difficult. In this research paper firstly the behavioral study of synchronous machine with PID controller and discrete filter is carried out of transfer by aid transfer function and In the second step point-by-point method using simulink show the transient behavior of the synchronous machine. The...
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...term use for the operation and objective of the organisation that have interest in other countries. For example Tesco, Ford, General Motor, McDonald, Disney, so many other companies. These companies have key interest to standardise their product for general acceptance. The international business becomes more complex. Tie between the different societies and organisations. (Meldrum, D.H) as businesses inter into new market it chances of 50% losses increases. Due to different in economic, political, cultural structure, policies, geography and currencies. These factor decreases profit ratio of international investment. There are no specific criteria to measure such in-stability. Every investor used their own method and measure. Uncertain condition of country make easy for international business to design their own stability criteria. (Considering risk in international business) Business has no idea about the local risk. It's difficult to operate and manage in such condition where the Culture, Social, Economic, Political, and legal structure are not stable. In such cause the international business need to take all the measurement either it`s Commercial, Culture, Social. Political or legal instability before enter into new market or country. 2. International business (McCulloch, C.1999)International business is started as with the formation of first national borders. Greek started such activity before the Christ follow by the British in 1600 when they establish the East India Company...
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...First Solar, Inc. Key Messages • PV power plant is a cost-effective energy resource • Well designed “Grid Friendly” PV plant actively stabilizes grid and enhances its reliability • PV variability can be managed with existing grid infrastructure through forecasting and site diversity with minimum impact © Copyright 2013, First Solar, Inc. 2 First Solar — Utility Scale PV Plant Leader Over 3GW Completed or In Development (10MW AC – 550MW AC Plants) © Copyright 2013, First Solar, Inc. 3 Utility Scale PV Power Plant Overview PV Module Arrays Combiner Boxes 300 to 690V (AC) 1000V (DC) Inverters Transformers Photovoltaic Combining Switchgear Substation 34.5kV (AC) Typical 69 to 525kV (AC) Gen Tie-line Power Grid © Copyright 2013, First Solar, Inc. 4 PV Module PV Module Arrays 1000V (DC) © Copyright 2013, First Solar, Inc. 5 Combiner Box Combiner Boxes • Aggregates DC wiring from multiple strings (80KW-160KW) • Provides single dc output to inverter 1000V (DC) © Copyright 2013, First Solar, Inc. 6 Utility Scale Solar Plant Inverters Inverters • Converts DC power to AC (low voltage) • Grid Management Functions (LVRT, Reactive Power, etc.) 300 to 690V (AC) 1000V (DC) • UL1741 and IEEE1547 compliant © Copyright 2013, First Solar, Inc. 7 Transformer • Increases low AC voltage to medium Transformers 300 to 690V (AC) AC voltage for Collection System 34.5kV (AC) Typical © Copyright...
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...TABLE OF CONTENT 1.0 Introduction 1 2.0 Elements of Breakdown 2 3.0 The Process of Breakdown 4 4.0 The End of Democracy 5 5.0 The Process of Re-equilibration 5 6.0 Conclusion 6 LIST OF MODELS Model 1: Relationship of Legitimacy, Efficacy and Effectiveness towards Stability and Performance 3 THE BREAKDOWN OF DEMOCRATIC REGIMES: CRISIS, BREAKDOWN & REEQUILIBRATION Introduction Many existing literature on the collapse of the democracy concentrated on rises of nondemocratic political powers or the fundamental structural tension that lead to the breakdown of democratic institution. In this publication, author, Juan J. Linz is giving attention to dynamic of the political process of breakdown by referring to tragic consequences of democratic collapse in German, Spain and Chile. This attention has begun during the author childhood where he was concerned with the fate of Spanish democracy, the fate his as citizen. This concern later had shared with Alfred Stepan who writes a dissertation on the breakdown of democracy in Brazil. Both of them get support and attention from many people and agencies. The focus firstly gets attention at the Seventh World Congress of Sociology at Varna, Bulgaria in 1970. In year 1973, with the support from the Concilium of International and Area Studies of Yale University, and the Joint Committee on Latin America of Social Science Research Council and the American Council of Learned Societies, Linz and Stepan chaired the conference...
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............................... 3 GROUND EFFECT AERODYNAMICS.............................................................. 4 CHORD DOMINATED GROUND EFFECT ................................................... 4 SPAN DOMINATED GROUND EFFECT....................................................... 5 AERODYNAMIC CENTERS IN GROUND EFFECT..................................... 6 AERODYNAMIC EFFICIENCY IN GROUND EFFECT ............................... 7 EKRANOPLANS.................................................................................................. 9 CONFIGURATION LAYOUT ......................................................................... 9 POWER AUGMENTATION RAM (PAR)..................................................... 12 LONGITUDINAL STABILITY...................................................................... 14 LATERAL STABILITY ................................................................................. 15 1. INTRODUCTION Wing-in-ground effect applies to vehicles design to fly at very low altitudes to take the advantage of increased in aerodynamic lift and reduced drag which occurs when a wing is in ground effect. The phenomenon of ground effect was observed as early as the Wright Brothers’ Wright Flyer I which flew in the presence of ground effect. During World War II, war planes which are low on fuel flew in ground effect in order to fly back to base in order to make use of the increase in efficiency when operating in ground effect. Despite this phenomenon...
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...term use for the operation and objective of the organisation that have interest in other countries. For example Tesco, Ford, General Motor, McDonald, Disney, so many other companies. These companies have key interest to standardise their product for general acceptance. The international business becomes more complex. Tie between the different societies and organisations. (Meldrum, D.H) as businesses inter into new market it chances of 50% losses increases. Due to different in economic, political, cultural structure, policies, geography and currencies. These factor decreases profit ratio of international investment. There are no specific criteria to measure such in-stability. Every investor used their own method and measure. Uncertain condition of country make easy for international business to design their own stability criteria. (Considering risk in international business) Business has no idea about the local risk. It's difficult to operate and manage in such condition where the Culture, Social, Economic, Political, and legal structure are not stable. In such cause the international business need to take all the measurement either it`s Commercial, Culture, Social. Political or legal instability before enter into new market or country. 2. International business (McCulloch, C.1999)International business is started as with the formation of first national borders. Greek started such activity before the Christ follow by the British in 1600 when they establish the East India Company...
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...Lesson 1, Writing Assessment Essay Topic: Sharing Power? Prospects for a U.S. Concert-Balance Strategy Date: 12 January 2015 Name: Angela Butts, LTC, USAR Dr. Patrick Porter is an Australian academic at the University of Reading in the United Kingdom. Dr. Porter published a monograph entailing a well reasoned argument on a power-sharing grand strategy based upon concert of power and balance of power systems. According Dr. Porter, these are the strategies that will cause the U.S. to no longer be hegemonic and maintain its powerful influence and status in the global system. I agree with Dr. Porter that the United States (U.S.) should employ these strategies in the future decades. However, I disagree that this is due to losing America’s global hegemony. The lost of hegemony would cause instability within the global system. In the future, I think the U.S. will move towards these strategies in order to produce stability while trying to maintain global leadership. Contrary, the focus could shift for the U.S. to build a “multi-partner” system for governments and nongovernment groups to work together on global issues. This is the goal of the Obama Administration in an effort to reduce competition and have closer ties to the major global powers. There are limited options for other countries to take over as a global hegemon. Unlike other countries, India may be the closest to becoming the next hegemon of the global system; however, it is not ready based on its structural...
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...motor and generator. They are used primarily as electrical power generators. They are usually large machines generating electrical power at hydro, nuclear or thermal power stations. Synchronous generators with power rating of several hundred MVAs are quite common in generating stations. Synchronous generators are the primary energy conversion devices of the world’s electrical power systems today. Because the rotor speed is proportional to the frequency of excitation, synchronous motors can be used in situations where constant speed drive is required. In industry, synchronous motors are used mainly where constant speed is desired. In industrial drivers, therefore synchronous motors are not as widely used as induction or dc motors a linear version of the synchronous motor (LSM) is being considered for high speed transportation systems of the future. An important feature of the synchronous motor is that it can drop either lagging or leading reactive current from the ac supply systems. A synchronous machine is a doubly excited machine. Its rotor poles are excited by a dc current and its starter buildings are connected to the ac supply. The air gap flux is therefore the resultant of the fluxes due to both rotor current and stator current. In a synchronous motor if the rotor field winding provides just the necessary excitation , the stator will draw no reactive current; that is the motor will operate at a unity power factor. If the rotor excitation current is decreased, lagging...
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...international policy, the condition and development of the country’s economy compared to the world situation and dominating countries, purchasing power of the currency, and other internal and external factors. The history of world exchange rate systems shows us that the world community (in its majority) has in fact shifted from the system of fixed exchange rates to floating exchange rate system. Currently there exist different combinations of floating and fixed exchange rate systems, together with specific economical instruments, created for exchange rate regulating. Since the development of production and a number of divisions of labor there existed such a phenomenon as commodity money. There was no other monetary system until 17th century when there appeared coins having an intrinsic value, not linked with commodity. Usually the value of the coin was associated with the content of gold in the coin. The exchange rate between different coins and different currencies depended on the content of gold in the coin as well, and equaled to the relative content of gold in the coins. In 17th century banks started issuing own banknotes which had the same purchasing power as coins and were backed by precious metals in the banks. People could convert these banknotes into precious metals if they wished so. With the development of this system (the so-called fractional reserve banking) and with the development of international relations the idea of the gold standard appeared. In 1870...
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...The Globalization of Democracy Building: A Polyarchic Dilemma When we look at the Middle East and democratization, we must realize that democracy in its current form is largely a Western concept. Democracy building on the part of the US outwards is a classic example of globalization. This paper will examine two theories of globalization: the interdependency theory of Waltz and Robinson?s view of globalization as one of power politics. It will then move on to examine globalization theory in regards to democracy building. Finally, this paper will seek to examine democracy building initiatives in two countries, Iraq and Lebanon. Theories of Globalization Waltz contends that we view globalization at interdependence, and that ?interdependence [is] again associated with peace and peace increasingly with democracy.? ? People, firms, markets matter more; states matter less,? because it is the economy that drives states to make decisions. As the world becomes more interdependent on one another, decisions are made as a collective whole in the economic field, not the independent political state. In many ways, Waltz suggests that Globalism is really Americanism spread around the globe. As the Cold War ended, it become clearer that the ideology that won out, a capitalist democracy, was the winner and dominant ideology. The theology behind it was that if a country is not transparent, with a flexible free market, then it will crumble. What if a country is looking to open its...
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...Assess the view that the main function of religion is to promote social stability (33 marks) Social stability refers to harmony and integration within society, the main function of religion has long been argued between sociologists depending on their perspective. Among those that agree are functionalists, for example Durkheim and his study on totem worship, on the other hand Marxists argue religion oppresses the proletariat in order to maintain a capitalist society. The main sociologists that support the view that the main functions of religious beliefs is to promote social stability are functionalists. They believe that religion performs functions and helps society, this is because society’s most basic need is the need for social order and solidarity so that its members can cooperate and to do this there needs to be value consensus, which without this individuals in society would pursue their own selfish desires and society would disintegrate. One functionalist that supports this argument is Durkheim which he states that religion and its institutions play a central part in creating and maintaining value consensus, order and solidarity. He distinguishes the difference between the sacred and the profane. He says that the sacred are the things set apart and forbidden that inspire feelings of awe, fear and wonder and are surrounded by taboos and prohibitions. By contrast, the profane are things that have no special significance. Therefore a religion is never simply a set of beliefs...
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...When people try to make the link between the behavior of states as well as people situation in the international system this require a deep study of what the international system itself is. In fact, international relation can be identifying as the neighborly relations between states in the global world. And these relations are mainly base on the need of state to security, and wealth for the states as well as for the people living in these states. At the beginning of the relations, the main goal was to reduce the cost causes by the distance being between two states. For the international relation to well work, peace has been centralized into the international system. Because without peace no relation can happened and be efficient. However,...
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...20 Unified Power Flow Controllers Ali Feliachi West Virginia University Azra Hasanovic West Virginia University 20.1 20.2 20.3 20.4 20.5 20.6 20.7 Introduction Power Flow on a Transmission Line UPFC Description and Operation Series Converter: Four Modes of Operation • Automatic Power Control Karl Schoder West Virginia University UPFC Modeling UPFC Steady-State or Load Flow Model • UPFC Dynamic Model • Interfacing the UPFC with the Power Network Control Design UPFC Basic Control Design • Power System Damping Control through UPFC Using Fuzzy Control Case Study Test System • Tracking Real and Reactive Power Flows • Operation under Fault Conditions Conclusion 20.1 Introduction An electric power system is an interconnection of generating units to load centers through high-voltage electric transmission lines. It consists of generation, transmission, and distribution subsystems, which used to belong to the same electric utility in a given geographical area. But, currently, the electric power industry is in transition from large, vertically integrated utilities providing power at regulated rates to an industry that will incorporate competitive companies selling unbundled power at possibly lower rates. With this new structure, which will include separate generation, distribution, and transmission companies with an open-access policy, comes the need for tighter control strategies. The strategies must maintain the level of reliability that consumers not...
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...Essay Power and stability in the Middle Ages were maintained through the hierarchical feudal social system, but it changed over time due to various factors. Birth of feudalism began in Europe from Charlemagne and William the Conqueror to England after the victory over King Harold Godwinson. This system was characterised into three large categories – the powerful, the spiritual and the powerless. The upper class were very powerful and had many privileges. A king controlled large areas of land and were able to give away the land for loyalty and protection. He “offered protection to the peasants…but he also exerted his power over them (Source D)”. William’s reign was long and stable, as he spread out his Norman lords so they could not rebel against him. The king also needed an army for protection and control over his land. As a result, he would pay nobles to provide knights for his legion. Nobles and knights required...
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