9 resultados para Remote area power supply systems

em AMS Tesi di Laurea - Alm@DL - Università di Bologna


Relevância:

100.00% 100.00%

Publicador:

Resumo:

One of the major issues for power converters that are connected to the electric grid are the measurement of three phase Conduced Emissions (CE), which are regulated by international and regional standards. CE are composed of two components which are Common Mode (CM) noise and Differential Mode (DM) noise. To achieve compliance with these regulations the Equipment Under Test (EUT) includes filtering and other electromagnetic emission control strategies. The separation of differential mode and common mode noise in Electromagnetic Interference (EMI) analysis is a well-known procedure which is useful especially for the optimization of the EMI filter, to improve the CM or DM attenuation depending on which component of the conducted emissions is predominant, and for the analysis and the understanding of interference phenomena of switched mode power converters. However, separating both components is rarely done during measurements. Therefore, in this thesis an active device for the separation of the CM and DM EMI noise in three phase power electronic systems has been designed and experimentally analysed.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In recent years, energy modernization has focused on smart engineering advancements. This entails designing complicated software and hardware for variable-voltage digital substations. A digital substation consists of electrical and auxiliary devices, control and monitoring devices, computers, and control software. Intelligent measurement systems use digital instrument transformers and IEC 61850-compliant information exchange protocols in digital substations. Digital instrument transformers used for real-time high-voltage measurements should combine advanced digital, measuring, information, and communication technologies. Digital instrument transformers should be cheap, small, light, and fire- and explosion-safe. These smaller and lighter transformers allow long-distance transmission of an optical signal that gauges direct or alternating current. Cost-prohibitive optical converters are a problem. To improve the tool's accuracy, amorphous alloys are used in the magnetic circuits and compensating feedback. Large-scale voltage converters can be made cheaper by using resistive, capacitive, or hybrid voltage dividers. In known electronic voltage transformers, the voltage divider output is generally on the low-voltage side, facilitating power supply organization. Combining current and voltage transformers reduces equipment size, installation, and maintenance costs. These two gadgets cost less together than individually. To increase commercial power metering accuracy, current and voltage converters should be included into digital instrument transformers so that simultaneous analogue-to-digital samples are obtained. Multichannel ADC microcircuits with synchronous conversion start allow natural parallel sample drawing. Digital instrument transformers are created adaptable to substation operating circumstances and environmental variables, especially ambient temperature. An embedded microprocessor auto-diagnoses and auto-calibrates the proposed digital instrument transformer.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In recent years Electric Vehicles (EVs) are getting more importance as future transport systems, due to the increase of the concerns relevant to the greenhouse gases emission and the use fossil fuel. The management of the charging and discharging process of EVs could provide new business model for participating in the electricity markets. Moreover, vehicle to grid systems have the potential of increasing utility system flexibility. This thesis develops some models for the optimal integration of the EVs in the electricity market. In particular, the thesis focuses on the optimal bidding strategy of an EV aggregator participating to both the day ahead market and the secondary reserve market. The aggregator profit is maximized taking into account the energy balance equation, as well as the technical constraints of energy settlement, power supply and state of charge of the EVs. The results obtained by using the GAMS (General Algebraic Modelling System) environment are presented and discussed.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In the field of Power Electronics, several types of motor control systems have been developed using STM microcontroller and power boards. In both industrial power applications and domestic appliances, power electronic inverters are widely used. Inverters are used to control the torque, speed, and position of the rotor in AC motor drives. An inverter delivers constant-voltage and constant-frequency power in uninterruptible power sources. Because inverter power supplies have a high-power consumption and low transfer efficiency rate, a three-phase sine wave AC power supply was created using the embedded system STM32, which has low power consumption and efficient speed. It has the capacity of output frequency of 50 Hz and the RMS of line voltage. STM32 embedded based Inverter is a power supply that integrates, reduced, and optimized the power electronics application that require hardware system, software, and application solution, including power architecture, techniques, and tools, approaches capable of performance on devices and equipment. Power inverters are currently used and implemented in green energy power system with low energy system such as sensors or microcontroller to perform the operating function of motors and pumps. STM based power inverter is efficient, less cost and reliable. My thesis work was based on STM motor drives and control system which can be implemented in a gas analyser for operating the pumps and motors. It has been widely applied in various engineering sectors due to its ability to respond to adverse structural changes and improved structural reliability. The present research was designed to use STM Inverter board on low power MCU such as NUCLEO with some practical examples such as Blinking LED, and PWM. Then we have implemented a three phase Inverter model with Steval-IPM08B board, which converter single phase 230V AC input to three phase 380 V AC output, the output will be useful for operating the induction motor.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This thesis deals with the sizing and analysis of the electrical power system of a petrochemical plant. The activity was carried out in the framework of an electrical engineering internship. The sizing and electrical calculations, as well as the study of the dynamic behavior of network quantities, are accomplished by using the ETAP (Electrical Transient Analyzer Program) software. After determining the type and size of the loads, the calculation of power flows is carried out for all possible network layout and different power supply configurations. The network is normally operated in a double radial configuration. However, the sizing must be carried out taking into account the most critical configuration, i.e., the temporary one of single radial operation, and also considering the most unfavorable power supply conditions. The calculation of shortcircuit currents is then carried out and the appropriate circuit breakers are selected. Where necessary, capacitor banks are sized in order to keep power factor at the point of common coupling within the preset limits. The grounding system is sized by using the finite element method. For loads with the highest level of criticality, UPS are sized in order to ensure their operation even in the absence of the main power supply. The main faults that can occur in the plant are examined, determining the intervention times of the protections to ensure that, in case of failure on one component, the others can still properly operate. The report concludes with the dynamic and stability analysis of the power system during island operation, in order to ensure that the two gas turbines are able to support the load even during transient conditions.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The aim of this research is to analyze the transport system and its subcomponents in order to highlight which are the design tools for physical and/or organizational projects related to transport supply systems. A characteristic of the transport systems is that the change of their structures can recoil on several entities, groups of entities, which constitute the community. The construction of a new infrastructure can modify both the transport service characteristic for all the user of the entire network; for example, the construction of a transportation infrastructure can change not only the transport service characteristics for the users of the entire network in which it is part of, but also it produces economical, social, and environmental effects. Therefore, the interventions or the improvements choices must be performed using a rational decision making approach. This approach requires that these choices are taken through the quantitative evaluation of the different effects caused by the different intervention plans. This approach becomes even more necessary when the decisions are taken in behalf of the community. Then, in order to understand how to develop a planning process in Transportation I will firstly analyze the transport system and the mathematical models used to describe it: these models provide us significant indicators which can be used to evaluate the effects of possible interventions. In conclusion, I will move on the topics related to the transport planning, analyzing the planning process, and the variables that have to be considered to perform a feasibility analysis or to compare different alternatives. In conclusion I will perform a preliminary analysis of a new transit system which is planned to be developed in New York City.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

La tesi tratta del progetto e della realizzazione di un riferimento in tensione simmetrico e stabile in temperatura, realizzato in tecnologia CMOS. Nella progettazione analogica ad alta precisione ha assunto sempre più importanza il problema della realizzazione di riferimenti in tensione stabili in temperatura. Nella maggior parte dei casi vengono presentati Bandgap, ovvero riferimenti in tensione che sfruttano l'andamento in temperatura dell'energy gap del silicio al fine di ottenere una tensione costante in un ampio range di temperatura. Tale architettura risulta utile nei sistemi ad alimentazione singola compresa fra 0 e Vdd essendo in grado di generare una singola tensione di riferimento del valore tipico di 1.2V. Nella tesi viene presentato un riferimento in tensione in grado di offrire le stesse prestazioni di un Bandgap per quanto riguarda la variazione in temperatura ma in grado di lavorare sia in sistemi ad alimentazione singola che ad alimentazione duale. Il circuito proposto e' in grado di generare due tensioni, simmetriche rispetto a un riferimento dato, del valore nominale di ±450mV. All'interno della tesi viene descritto il progetto di due diverse architetture, entrambe in grado di generare le tensioni con le specifiche richieste. Le due architetture sono poi state confrontate analizzando in particolare la stabilità in temperatura, la potenza dissipata, il PSRR (Power Supply Rejection Ratio) e la simmetria delle tensioni generate. Al termine dell'analisi è stato poi implementato su silicio il circuito che garantiva le prestazioni migliori. In sede di disegno del layout su silicio sono stati affrontati i problemi derivanti dall'adattamento dei componenti al fine di ottenere una maggiore insensibilità del circuito stesso alle incertezze legate al processo di realizzazione. Infine sono state effettuate le misurazioni attraverso una probe station a 4 sonde per verificare il corretto funzionamento del circuito e le sue prestazioni.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Nowadays, there is a boom in the use of electrification. Electric vehicles are gaining interest worldwide due to various factors, including climate and environmental awareness. In this thesis, a step-down isolated power supply for electric tractors is investigated, specifically the phase-shifted full-bridge (PSFB) DC-DC with synchronous rectification and zero-voltage switching (ZVS). This converter was selected for its high-power capacity with high efficiency. A 3500 W PSFB converter with peak current control (PCCM) is designed and modeled in MATLAB. The input voltage range is from 550 V to 820 V and the output voltage range is limited to 9 V to 16 V with a maximum output current of 250 A. All components were commercially designed and selected, including magnetics for the high-frequency transformer and inductors, taking into account loss calculations. Zero voltage switching for the lagging leg is achieved at 13% to 100% load. The proven efficiency of the converter is around 90

Relevância:

100.00% 100.00%

Publicador:

Resumo:

This master's thesis investigates different aspects of Dual-Active-Bridge (DAB) Converter and extends aspects further to Multi-Active-Bridges (MAB). The thesis starts with an overview of the applications of the DAB and MAB and their importance. The analytical part of the thesis includes the derivation of the peak and RMS currents, which is required for finding the losses present in the system. The power converters, considered in this thesis are DAB, Triple-Active Bridge (TAB) and Quad-Active Bridge (QAB). All the theoretical calculations are compared with the simulation results from PLECS software for identifying the correctness of the reviewed and developed theory. The Hardware-in-the-Loop (HIL) simulation is conducted for checking the control operation in real-time with the help of the RT box from the Plexim. Additionally, as in real systems digital signal processor (DSP), system-on-chip or field programmable gate array is employed for the control of the power electronic systems, and the execution of the control in the real-time simulation (RTS) conducted is performed by DSP.