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A Multi-Source Inverter for Electric Drive Vehicle Applications

Abstract Energy storage systems in electric drive vehicles can be connected to the high voltage DC link through passive or active configurations. Passive configurations put sources in parallel without any decoupling converter among sources which increases the number of series cells in battery and Ultra-Capacitor (UC). Also, due to lack of control over UC, its stored energy cannot be utilized efficiently. Active configurations exploit DC/DC converters to control the sources separately. However, existence of DC/DC converters with bulk magnetics increases the system volume and weight, and decreases the efficiency due to inductors’ series resistances. Recently, multi-source inverters as a new concept in electric drive vehicle applications is getting attraction in both academia and industry. Reduction in the size of the battery pack and battery cell-balancing electronics, as well as higher efficiency due to single stage conversion and removal of the magnetics are the advantages of such structures. In this paper, a reconfigurable multi-source inverter with the ability of generating different combinations of the input DC sources for electric drive vehicle application is proposed. Introduction The global interest in energy efficient electric drive vehicles due to their superior performance over the traditional Internal Combustion Engine (ICE) cars is increasing daily. Replacing ICE cars with electric drive vehicles can save a reasonable amount of oil products as well as reduction in greenhouse gases since transportation consumes up to 63.7% of petroleum and releases 14% of the greenhouse gases worldwide [1]. Hybrid Energy Storage Systems (HESS) using battery, and Ultra-Capacitor (UC) are getting attraction in Electric Vehicles (EVs), Hybrid Electric Vehicles (HEVs), and Plug-in Hybrid Electric Vehicles (PHEVs). An HESS can be designed in two configurations, i.e. passive parallel (Fig.1 (a)) and active (Fig.1 (b)) [2]. In the primary passive parallel structure, the battery pack and UC cells are placed in parallel, which is simple to implement. However, due to high voltage ratings of the battery pack, a high number of UC cells should be placed in series to match battery pack’s voltage rating. Moreover, due to lack of a decoupling converter between the sources, effective utilization of the stored energy in UC pack is not possible. Active configurations exploit high-power DC/DC converters as the power conditioning units for voltage matching of the sources with high voltage DC bus and current control of the sources. Due to existence of magnetics, electrolytic capacitors and cooling systems in such converters, volume, weight, and the price of the system will increase [3]. (a) (b) Fig.1: HESS configurations, (a) passive parallel, (b) active configuration. A new approach towards utilization of the HESS in energy efficient vehicles, is to use multi-source inverters. A multi-source inverter is a power electronics system that connects several DC sources to the same AC output through a single stage conversion [4], [5]. Using such structure removes magnetics from the circuit and improves the overall system’s volume, weight, and efficiency. In traditional passive or active configurations the voltage at the high voltage DC link (input of the inverter) is fixed; however, in a multi-source structure this voltage is not fixed anymore. In this regards, a multi-source structure is advantageous as the switching losses of the Voltage Source Inverter (VSI) connected to a fixed high voltage DC bus are higher since switching losses of a VSI are proportional to the voltage of the DC bus [6]. The variable DC link voltage also gives the degree of freedom to costume design the voltage ratings of each source. This will decrease the voltage rating of the battery pack which leads to decrease of the cell-balancing requirements and lowers the final price of the battery pack. In [4] a multi-source inverter using T-type inverter structure has been proposed which is able to connect two DC sources to the same AC output. However, adding up the voltage sources is not possible; thus, the voltage of the main DC source should be the same as the high voltage requirements of the electric motor, which does not solve the issue of high-voltage battery packs. In this paper, a three-phase bidirectional multi-source inverter for HESS applications in electric drive vehicles is proposed, which is able to add-up the DC sources. Thus, the voltage ratings of each source can be kept low. This will not only simplify the cell-balancing circuits in the battery pack, but also reduces the final price of the battery, since a governing criteria for battery price is its output voltage and power requirements [7]. Proposed Topology Fig.2 indicates the structure of the proposed multi-source inverter. Two DC sources with different voltage ratings can be used at the DC sides. The DC source labeled with V1 is chosen to be a battery pack, and the second DC source labeled V2 can be either a battery pack or a UC bank. The choice of the second source depends on the system design and environmental criteria. For example in the extreme cold climates where temperature goes down below –15℃ , lithium-ion batteries stop working [8]. In this situation, using UC bank as a second source to warm-up the battery pack is highly recommended as UC can offer performance in wide temperature range (–40℃ to 70℃) . Moreover, UCs can handle high surge currents due to their high specific power characteristics. Thus, during brakes, when a sudden rush of high amplitude current is released, UC bank can be used to capture the regenerated energy, while the battery pack is disconnected from the system. This will increase the life span of the battery pack as it does not have to undergo charging with high current amplitudes during brakes. Moreover, since the second source undergoes repetitive charge/discharge cycles in a driving-cycle, it is better to utilize a source that can handle repetitive charge/discharge events. Since UCs offer higher number of charge/discharge life cycles, they can be of better choice for this source. Once again it is worth mentioning that choosing the second source is a design criterion, and another battery pack instead of UC bank can be used in case longer distance coverage is of more interest. Fig.2: Proposed multi-source inverter. Table 1 indicates the inverter modes of operation, switching states, and VVSI which is the variable DC input of the VSI as the third part of the inverter. Also, the effect of each switching state on the UC bank as the second source can be seen in the table. Considering that at least one of the sources is always connected to the load, the inverter can generate four voltage values at the input of the VSI, where one voltage level can be generated using two different switching commands (Mode 3). Since the VSI has eight switching states for each input voltage, the inverter has 40 switching states. Some of these switching states are redundant, which can be used for controlling purposes. Space vector representation of these switching states in αβ frame using (1) and (2) is shown in Fig.3. VαVβ=2/31–0.5–0.5032–32vAnvBnvCn (1) vAn=13(vAB–vCA)vBn=13(vBC–vAB)vCn=13(vCA–vBC) (2) Table 1: Switching states of the inverter and their effects on the UC pack Mode Switching State S1 S2 S3 S4 S5 S6 VVSI Effect on UC pack if IinVSI≥0 1 1 0 1 0 1 1 0 V2 Discharge 2 2 1 0 1 0 0 1 V1–V2 Charge 3 3 1 0 1 1 0 0 V1 Neutral 4 1 0 0 0 1 1 V1 Neutral 4 5 1 0 0 1 1 0 V1 V2 Discharge Operating modes of the converter are as follows, Mode 1: Only the second DC source is supplying the load. Mode 2: The first DC source is charging the second DC source while supplying the load, as well. Mode 3: Only the first DC source is connected to the load. Mode 4: The input voltage of the VSI is equal to the summation of both voltage sources and both sources are being discharged in the load. Fig.4 indicates the simplified torque-speed characteristics of the electric motors for different input voltage values [9], [10]. As it can be seen, by changing the input voltage of the electric motor, different torque-speed characteristics can be obtained. In this regard, each source can be designed such that it matches the electric motor’s voltage rating while its output voltage is kept as low as possible. This will decrease the cell-balancing requirements of the sources. For instance in mode 4, when the higher toque values or higher speed regions are required, two DC voltage sources are put in series to generate a high voltage amplitude at the input side of the VSI. In this way, the high voltage requirements of the electric motor during peak powers can be met while a battery pack with lower voltage rating is used. Also, the input power of the electric motor comes from the inverter and the input power of the inverter is the product of its input voltage and current as described by (3). During peak power requirements such as hill climbing or acceleration events, this peak power can be provided in two ways, i.e., increase of current while the voltage is constant, or increase of voltage while keeping the current constant. In stiff DC link structures, the increase of current was used to compensate for high power requirements. With variable DC link structures, current increase can be maintained in a certain level during peak power requirements with increment of the DC link voltage. This will increase battery pack’s life span as discharging battery with high current amplitudes degrades its life. Pinvinput=VVSI*IinVSI (3) Simulation and Experimental Results Matlab/Simulink was used to assess the performance of the proposed inverter. The voltage of the battery pack is set to be 300 V and its initial SOC is 80%. The UC bank has a rated voltage of 100V, capacitance of 84 F, and initial SOC of 90%. Space Vector Modulation (SVM) is used to control the switching actions of the inverter. Fig.5 indicates the current, voltage, and SOC of the battery pack, and UC bank, during each mode of operation. In mode 1, only the UC is supplying the load; thus, battery current is zero and its SOC is not changing. In mode 2 UC is being charged by the battery and its SOC is increasing. In mode 4 both of the sources are supplying the load and their SOCs are decreasing. In mode 3, only battery is supplying the load. Consequently, UC current is zero, and its SOC and voltage are constant. Fig.6 is the simulation results of the inverter output voltage and current. Also, load current and line voltage during transition from mode 1 to mode 2 can be seen. Experimental results of a scaled down lab prototype is shown in Fig.7 for line voltage and three phase load currents. As it can be seen, experiments are in agree with simulations and theory. Fig.6: Simulation results of the inverter current and voltage. (a) Load current, (b) Load current during transition from mode 1 to mode 2, (c) Line voltage, (d) Line voltage during transition from mode 1 to mode 2. (a) (b) Fig.7: Experimental Results. (a) Line Voltage, (b) Load Current. Conclusion and Future Work A new structure for Hybrid Energy Storage Systems is proposed in this paper, which removes the need for DC/DC converters. Since there is no magnetics in the circuit, the structure can be compact and light which is of high interest for electric drive vehicles. Operating modes of the proposed multi-source inverter are described, and simulation and experimental results are carried out as a proof of the concept. Control over the stored energy of each source is possible and the sources can exchange energy as well. Space Vector Modulation is used to control the switching actions of the inverter. In the full paper, detailed description of the inverter’s operation, as well as modulating technique with more simulation and experimental results will be provided. REFERENCES [1] Akimoto K., F. Sano, A. Hayashi, T. Homma, J. Oda, K. Wada, M. Nagashima, K. Tokushige, and T. Tomoda, “Consistent assessments of pathways toward sustainable development and climate stabilization”, Natural Resources Forum 36, 2012. [2] S. M. Lukic, S. G. Wirasingha, F. Rodriguez, J. Cao and A. Emadi, “Power Management of an Ultracapacitor/Battery Hybrid Energy Storage System in an HEV,” Proc. of the 2006 IEEE Vehicle Power and Propulsion Conference, Windsor, 2006, pp. 1-6. [3] A. Khaligh and Z. Li, “Battery, ultracapacitor, fuel cell, and hybrid energy storage systems for electric, hybrid electric, fuel cell, and plugin hybrid electric vehicles: State of the art,” IEEE Trans. Veh. Technol., vol. 59, no. 6, pp. 2806–2814, Jul. 2010. [4] L. Dorn-Gomba, P. Magne, B. Danen and A. Emadi, “On the Concept of the Multi-Source Inverter for Hybrid Electric Vehicle Powertrains,” in IEEE Transactions on Power Electronics, available at “ http://ieeexplore.ieee.org/abstract/document/8078206/”. [5] A. Emadi and P. Magne, “Power converter,” Apr. 25 2014, CA Patent App. CA 2,831,252. [6] F. Z. Peng, J.-S. Lai, J. W. McKeever, and J. VanCoevering, “A multilevel voltage-source inverter with separate dc sources for static var generation,” IEEE Transactions on Industry Applications, vol. 32, no. 5, pp. 1130–1138, Sep 1996 [7] E. Chemali and A. Emadi, “On the concept of a novel Reconfigurable Multi-Source Inverter,” 2017 IEEE Transportation Electrification Conference and Expo (ITEC), Chicago, IL, 2017, pp. 707-713. [8] T.B. Reddy, “Linden’s Handbook of Batteries (Fourth Edition),” published by McGraw-Hill, 2011. [9] T. A. Burress, S. L. Campbell, C. L. Coomer, C. W. Ayers, A. A. Wereszczak, J. P. Cunningham, L. D. Marlino, L. E. Seiber, and H. T. Lin, “Evaluation of the 2010 Toyota Prius hybrid synergy drive system,” Oak Ridge National Laboratory, Tech. Rep. ORNL/TM-2010/253, Jan 2008. [10] M. Ehsani, Y. Gao, A. Emadi, “Modern Electric, Hybrid Electric, and Fuel Cell Vehicles Fundamentals, Theory, and Design,” Second Edition, CRC Press, New York, 2010.
DU Marketing Plan for Affordable Solar Company Strategic Focus and Plan Essay.

based on the solar project. I uploaded the template and requirement is only the highlighted sections. I also attached a previous assignment for reference. At the end of Week 4, you will submit a substantial draft to your instructor for grading and feedback. Be sure to read Appendix A in the text and use the marketing plan outline (Links to an external site.) from the Files folder in Canvas. It is recommended that you start working on your draft in Week 2 after your instructor has approved your topic. Complete as much as you are able in order to get an initial draft (approximately 75% of the final paper). Remember, the more you complete on this initial draft, the greater the input that the professor can provide and the less work you will need to do for the final draft.Submit a copy of the marketing plan draft to the Week 4: Course Project Draft Upload module in Canvas for grading by your instructor.A.Cover Page1.Marketing Plan for organization/company name:2.Proposed by:3.Submitted to:4.Date: B.Table of ContentsSuggested number of pages1… Executive Summary……………………………………………………………………………. 1.02… Company Description………………………………………………………………………….. 0.53… Strategic Focus and Plan…………………………………………………………………….. 1.0a.Mission/Vision Statementsb.Goalsc.Core Competency and Sustainable Competitive Advantage4… Situation Analysis……………………………………………………………………………….. 1.0a.SWOT analysisInternal Strengths and Weaknesses: Management, Offerings, Marketing, Personnel, Finance, Manufacturing, and Research and Development (R & D)External Opportunities and Threats: Consumer/Social, Economic, Technological, Competitive, and Legal/Regulatoryb.Industry Analysisc.Competitor Analysisd.Customer Analysis
DU Marketing Plan for Affordable Solar Company Strategic Focus and Plan Essay

VIT Autozone Motor Shop Database and UI Design Programming Project

VIT Autozone Motor Shop Database and UI Design Programming Project.

Deliverables Description Due week (Weightage) Proposal document The proposal is a document to be uploaded on Moodle that contains the B2C company, products with project details of your choice to work on. The group details need to be included in the document and submitted in LMS. Week 4 (10%) Database and UI designUser interface of the project using HTML/CSS/JSP needs to be demonstrated and documented. Database model with the demonstration in MySQL to the lecturer. The database and UI design need to be submitted in LMS. Week 7 (30%) Demonstration, Project Code with report The J2EE project including the required functionalities needs to be demonstrated to the lecturer. The project code with the report needs to be submitted in LMS. Week
VIT Autozone Motor Shop Database and UI Design Programming Project

Brazilian Democratic Transition And Consolidation

essay writing help Brazilian Democratic Transition And Consolidation. Brazil, which is the largest country in South America and fifth largest country in the world, is also a political and economic leader in its continent. However, among the many nascent Latin American democracies, Brazil’s road to democracy was the most challenging (Linz and Stepan, 1996, p 166). Its democratization (1974-89) followed a cyclical pattern which alternated back and forth between quasi-democratic and authoritarian systems (Huntington, 1991, p 41). After a brief period of electoral democracy in the 1930s, military coups took control of the nation. The next three decades witnessed Brazil’s long authoritarian rule that was governed by a series of stable but harsh dictatorial regimes. In the 20th century, Brazil embarked on the path to electoral democracy, which was led by Vargas, the elected President. However, his rule plagued Brazil with several rebellions caused by military officers, the spread of communism across the country, and brutal tortures by government agents. Thus, the short period of democracy ended and Vargas established a populist dictatorship. In 1945, military coup supported by the Brazilian oligarchy finally overthrew the ineffective and harsh leader. Brazil then plunged into a long authoritarian rule from 1964 to 1985, in which the military government held power and democratized Brazil through five major stages (Codato, 2006). It was this period of uncertainty and unrest caused by violent prolonged military dictatorship that created the climate for political compromise and democratic obligation. Causes for the breakdown of authoritarianism such as splits in the military led to the demand for re-democratization in Brazil. Democratization finally occurred in 1974 and coincided with the ‘Third Wave’ of democracy. One will be surprised and wonder how Brazil’s long period of authoritarianism under the reign of three capable leaders, Branco, Silva, and Medici’s leadership sparked a possible shift to a democracy. What factors pressured each successive military leader to concede to democratization? After a long military dictatorship, what caused the next administration, Geisel, to democratize Brazil? Finally, to what extent has democracy been consolidated? This paper will attempt to answer the above questions. I will first give a contextual knowledge about Brazil’s political transition which occurred in five stages, over the span of thirty years. Next, I will explain the reasons that caused the breakdown of authoritarianism in Brazil. Finally, I will evaluate the extent to which democracy in Brazil is consolidated based on its obstacles and threats, and suggest ways in which the democracy can be stabilized. History of Brazil’s Political Transition Establishing military dictatorship The first stage of Brazil’s political transition corresponds to the Castello Branco and Costa e Silva administrations (March, 1964 – December, 1968). The military ceased its leadership in 1961 when vice president João Goulart resigned from presidency. He resigned with hopes of being reinstated again by popular demand, but was denied by the military’s fear of him being a communist. Following his resignation, the regime encountered difficulties in finding a new leader as no civilian politician was suitable for the existing revolutionary factions in governance. After fifteen days, Branco became the new president and managed to reform the political-economic system (Hudson, 1997). Being anti-Goulart and disapproving of his ruling methods, Branco rejected the extension of his presidency beyond Goulart’s term, or the institutionalization of the military’s power. Despite the divides and instability in the military regime, Branco tried to instill a degree of democracy into his governance, but in the process, he had to accept the succession of Minister of Army, Costa as his next president. Under Costa’s reign, the military regime implemented and strengthened new diplomatic restrictions. Foreign relations with the U.S were maintained and highly valued as it was beneficial to Brazil’s development during that period. Thus, the process of constituting military dictatorship during the 1960s resulted in splits in the regime and increasing U.S role which paved the way for the initial democratic transition. Consolidation of the military dictatorship Unfortunately, the hard-liner Costa e Silva died unexpectedly in October 1969. Military officers took a vote among them and chose General Garrastazú Médici as the next president till 1974. Medici also represented the hard-line left side of politics and aimed to exert control to turn Brazil into a great authoritarian power (Hudson, 1997). He worked towards consolidating the dictatorship that was instituted by Branco and Silva. Under the unpopular Medici government, Brazil did not have a political party or a well-established set of institutions and laws. His rule marked the era of terrorist attacks in the cities, rampant kidnapping of diplomats, including the U.S ambassador, and a widespread antiguerrilla north of Brazil. Torture, corruption and denial of political rights were a common sight. As a result, conflicts with the Roman Catholic Church occurred and eroded relations with the U.S. Transformation of the military dictatorship In this atmosphere of the probable decline of long authoritarian rule, retired General Ernesto Geisel took up the next presidency term (1974-79), and announced the politics of regime transformation of the dictatorship (Codato, 2006). Part of his campaign involved the replacement of several military commanders with trusted liberal officers and the commencement of Brazil’s political opening, known as the return to democratic rule. Hard-liners rejected his move away from repression. In 1978, opposition demanded reinstatement of basic civil liberties, especially freedom of speech of the press, an end to torture and the release of political exiles. While the opposition successfully created a discussion of these concerns, the Geisel government took the initiative in tackling them (Mainwaring, 1986, p 155). President Geisel also sought to maintain high economic growth rates, while controlling the income inequality and satisfying the middle income class that Medici failed to achieve (Hudson, 1997). However, his inability to handle the 1973 oil crisis shock made it evident that military rule had to end. Decomposition of the military regime Joao Figueiredo’ office term marked the last few years of military regime. He attributed his acceptance of presidency after Geisel’s term to a sense of duty to complete the disintegration of the military regime, rather than political ambition (Hudson, 1997). He intended to make Brazil democratic, but was faced with resistance from the hard-liners. The latter reacted to the opening of the political system with a series of terrorist bombings causing instability. Authorities discovered that widespread terrorism in the country was directly linked to military involvement after an April 1981 bombing incident. However, Figueiredo was a soft-liner and could not bear to punish these offenders. Hence, the public saw a need to immediately end military rule as the regime’s inaction to terrorism proved its weakness in ensuring national safety. Moreover, Figueiredo’s leadership led Brazil to experience many serious problems such as hyperinflation, declining productivity and an escalating foreign debt, all of which resulted in Brazil’s moribund economy. The government adopted several economic policies to address their mounting foreign debt, such as increasing exports, and developing Brazil’s petroleum exploration by foreign companies. Figueiredo also wanted to build stronger foreign ties with other countries, but his heart condition which required a bypass surgery, removed him from the situation. Consequently, political and economic stability in Brazil went downhill. I believe that one probable reason for the collapse of Brazil’s authoritarian regime was the frequent health problems in soft and hard-liner leaders, or their obsession with power that could not be fulfilled. Furthermore, the lack of a common established institution and party identity weakened the authoritarian governance with each successive regime. Transition to a liberal democratic regime In 1985, Brazil elected a new president, 74 year-old Tancredo Neves, who had been one of the important leaders of the opposition to the military regime which took power in 1964. Unfortunately, Neves died before assuming office, so the elected Vice-president elect, Jose Sarney, took over the Executive Office on March 15, 1985, bringing an end of 21 years of military rule (Mainwaring, 1986, p 149). This final stage of Brazil’s road to democracy is a transition to a liberal-democratic regime under the Sarney administration, from 1985-90 (DreidussBrazilian Democratic Transition And Consolidation

University of Michigan Fab 5​

University of Michigan Fab 5​.

Hi everyone i need help in this and the topic is (University of Michigan Fab 5 ) if you google the topic you will know more about the topic just put it in google its sport issue Ethical Issues in SportsResearch the given scenario. Using complete sentences, answer the questions below.What is your given scenario: What is the nature of the problem? (2 paragraphs)When and where did it occur?What is unethical about the situation?Who all were affected in the situation? How?What could have been done to change the outcome of the situation?Did the person who committed the unethical act receive an appropriate punishment? Why or why not?Did they have an appropriate response?
University of Michigan Fab 5​

Mike Cole: Vygotsky’s ZOPD and Changing the Environment discussion

Mike Cole: Vygotsky’s ZOPD and Changing the Environment discussion.

Watch and comment (required) on one of the following videos. Try to connect your comment to one of the readings from this week.Mike Cole: “Vygotsky’s ZOPD and Changing the Environment Link (Links to an external site.)Links to an external site.Reciprocal Teaching in the Classroom Link (Links to an external site.)Links to an external site.ZOPD as “Wise Pedagogy” with Kris GutierrezLink (Links to an external site.)Links to an external site.
Mike Cole: Vygotsky’s ZOPD and Changing the Environment discussion