Новинка

4839 руб.

Space vector pulse width modulation (SVPWM) is an optimum pulse width modulation technique for an inverter used in a variable frequency drive applications. It is computationally rigorous and hence limits the inverter switching frequency. This book discusses a time equivalent SVPWM and neural Network based SVPWM technique for a five-phase voltage source inverter in under modulation region. A neural network has the advantage of very fast implementation of an SVPWM algorithm that can increase the inverter switching frequency. The scheme has been simulated and comparative study is given with the existing PWM schemes. The simulation results are given to validate the concept of proposed schemes.
Новинка

6690 руб.

In this book a phase-difference angle (PDA) controlled pulse width-modulated (PWM) inverter instead of phase voltage modulation and/or frequency changing is proposed to control the speed, and position of a two-phase induction motor. Several characteristics of a two–phase induction motor driven by the PDA inverter are studied to verify the improvement of the motor performances. Also, speed, and position tracking are achieved using the proposed control technique. The book covers in more details the main principles characteristics of the two-phase induction motor especially at voltage, frequency, PDA changing. The difference among them is studied carefully to conclude the best control method. For unbalanced operation of the two-phase induction motor when used either as a servomotor or single-phase applications. The method of symmetrical components transformation is used to simplify the steady state analysis of the machine.. An experimental prototype, which consists of a PC computer based controller, a PDA inverter, and two phase induction motor is used to verify the validity of the proposed control technique .
Новинка

4839 руб.

The three phase inverter (using MOSFETs) is designed successfully.The PWM pulses are generated using VHDL.The Field Programmable Gate Array is used.The four modes 00 to 11 are used to change the frequencies, four different frequencies are used.The readmode index 0000 to 1010 are used to change the intensity or amplitude of the frequencies. Maximum intensity will be achieved at 1010 readmode index.This is the design of Three Phase Inverter and provide the flexibility to change the frequency as well as amplitude or intensity of the circuit.These PWM pulses are used to the inverter by using IGBT also.The three inverter is very important for Agriculture field. Because most of the Agriculture pumps are run on Three-Phases.If the battery sources run on renewable energy then the Three- phase inverter is very useful.As four different frequencies are generated then this system becomes universal system because Every country they have different Mains supply frequency.
Новинка

9716 руб.

This book presents a new inverter phase-leg configuration that is inherently immune to shoot- through failures, eliminating one of the most serious failure modes in the conventional phase-leg configuration. The augmented phase-leg configuration (APLC) requires a single command signal and a simplified gate drive configuration to control the phase leg operation. The APLC also provides a significant advantage of eliminating the need for introducing dead-time intervals in the control of standard inverter phase legs. Very low levels of both harmonic distortion and nonlinearity are demonstrated using this new phase-leg configuration, making it attractive for many motor drive applications including low-frequency sensorless vector control, flux estimation, and open- loop voltage control. An alternative APLC topology is presented using a synchronous rectifier MOSFET that offers reduced losses by decreasing the forward conduction drop of the series diode. The results of this book provide valuable techniques and tools for developing new integrated power electronic modules that are highly integrated, intelligent, and robust.
Новинка

5790 руб.

The design and analysis of an experimental study on single-phase Pulse Width Modulation inverter are presented in this work. The study also aims to enhance knowledge on experimental studies in the lab. In this work, Implementation and analysis of PWM switching pulses with digital technique for single phase full bridge inverter is presented. A switching strategy will be proposed to be used for full bridge single phase inverter. The main advantage of these strategies is that it does not requir additional circuit to generated inverter’s dead time. In this book, the PWM equations are studied and the switching pulses are calculated. This research investigates several control techniques applied to the Single Phase Inverter in order to ensure an efficient voltage utilization and better harmonic spectrum. A modeling and control strategy of a single phase Inverter is also investigated. Computer simulation results using Simulink/Matlab program are reported and discussed together with a comparative study of the different control techniques.The single phase full bridge inverter implemented using IGBT has been developed to test the switching pulses generated by micro-controller (AT89S52).
Новинка

5790 руб.

This work focuses on the performance analysis of a reduced switch three phase Z-source inverter fed cost effective induction motor drive system. In the proposed approach, instead of a conventional six switch three phase inverter a four switch three phase Z-source inverter is utilized. This reduces the cost of the inverter, the switching losses, and the complexity of the control algorithms. The new Z-source inverter system provides ride-through capability during voltage sags, reduces line harmonics, improves power factor, reliability and extends output voltage range. Validations of the theory and reduction methods are performed experimentally. This proposed method is able to reduce conduction noise in contrast with the existing conventional inverters. Analysis, simulation and experimental results are presented to demonstrate these new features.
Новинка

4839 руб.

Online Optimal Pulsewidth Modulation (OPWM) for a Multilevel Inverter explains a control scheme in controlling a 5-level Cascaded H-bridge Multilevel Inverter (CHMI) output voltage based on the OPWM switching strategies. For better CHMI output voltage magnitude control resolution, a curve fitting technique (CFT) for online computation of the OPWM switching angles is presented. Focus is given on the CFT and the multilevel control design aspect of the control scheme for the CHMI. This control scheme is generally suitable for AC power supply applications that do not involve variations in the multilevel inverter operating frequency. In addition, its suitability is also identified for applications that require high quality output voltage but at the same time do not allow increase in the multilevel inverter power devices switching frequency. This may be due to the technological limits of the power devices employed for high voltage applications or certain environmental condition. To show the feasibility of the control scheme, results of a simulation study and experimental work on a 5-level CHMI operation are presented.
Новинка

8755.8 руб.

How to acquire the input frequency from an unlocked state A phase locked loop (PLL) by itself cannot become useful until it has acquired the applied signal's frequency. Often, a PLL will never reach frequency acquisition (capture) without explicit assistive circuits. Curiously, few books on PLLs treat the topic of frequency acquisition in any depth or detail. Frequency Acquisition Techniques for Phase Locked Loops offers a no-nonsense treatment that is equally useful for engineers, technicians, and managers. Since mathematical rigor for its own sake can degenerate into intellectual «rigor mortis,» the author introduces readers to the basics and delivers useful information with clear language and minimal mathematics. With most of the approaches having been developed through years of experience, this completely practical guide explores methods for achieving the locked state in a variety of conditions as it examines: Performance limitations of phase/frequency detector–based phase locked loops The quadricorrelator method for both continuous and sampled modes Sawtooth ramp-and-sample phase detector and how its waveform contains frequency error information that can be extracted The benefits of a self-sweeping, self-extinguishing topology Sweep methods using quadrature mixer-based lock detection The use of digital implementations versus analog Frequency Acquisition Techniques for Phase Locked Loops is an important resource for RF/microwave engineers, in particular, circuit designers; practicing electronics engineers involved in frequency synthesis, phase locked loops, carrier or clock recovery loops, radio-frequency integrated circuit design, and aerospace electronics; and managers wanting to understand the technology of phase locked loops and frequency acquisition assistance techniques or jitter attenuating loops. Errata can be found by visiting the Book Support Site at: http://booksupport.wiley.com
Новинка

6690 руб.

The phase-locked loop (PLL) is a feedback control system, used to lock the output frequency and phase according to the frequency and phase of input signal. It can also be used as a frequency synthesizer for modulation and demodulation circuits. In general, PLL is used in both transmitting and receiving terminals of wireless communication systems. A nearly description of PLL appeared in the paper by Appleton in 1923. It was conceived by H. De Bellecize in 1932. Since then, it is widely used in applications involving automatic control of phase or frequency, such as applications in communications, control systems, measurements and instrumentation and in many other applications. The synchronization of horizontal and vertical scan in televisions produced the first widespread use of PLL. One of the first large-scale industrial applications of the PLL (back in the yearly 1950s) was the color sub-carrier recovery in color TV receivers. This work illustrates the modeling of high speed PLL applicable for very high frequency (VHF) communication systems. Details of theoretical estimation of the model and its simulation on MatLab Platform in behavioral level is also presented in the book.
Новинка

3549 руб.

The wind power is a popular form of energy generation, the construction of wind farms and small wind electric generators are not universally welcomed because of the power quality issues due to which the converted energy could not be used more effectively. The frequency mismatch is one of the major crisis under the power quality issues when the renewable energy system is connected to the grid. Therefore the main objective of this project is to equalize the number of cycles per second in the grid as well as number of cycles per second in the inverter under different load conditions at various time periods. Hence the proposed project regarding frequency control scheme using grid integrated inverter for wind mill applications effectively compromises the drawbacks. Mainly the frequencies mismatch in the existing systems by equalizing the frequencies difference between the grid as well as the inverter.
Новинка

6026 руб.

Nowadays, vector control of induction motor drives are increasingly employed in industrial drive systems, motor works on best performance at certain voltage and frequency for certain loads. This project describes a generalized model of the three-phase induction motor by using vector control method and its computer simulation using MATLAB/SIMULINK, it presents the advances made in vector control as applied to high performance AC motor drives. By using this application, it can achieve speed control by controlling the reference speed value and torque value to keep the electromagnetic torque at a constant value. Machine models in d-q representation, implementation issues with AC induction motor, inverters and converters, parameter effects for induction motor vector control are dealt with and simulation results from the project are presented and discussed by computational calculation and graphs to support this theory. The large scope in this model can lead the algorithm designers to direct their efforts to the promising areas and avoid impossible tasks. From this project, the readers can approximately understand the principle of vector control in three-phase AC induction motor drive.
Новинка

4839 руб.

Voltage Source Inverters(VSI) are widely used in Variable frequency drives, power conditioning equipment, Flexible AC transmission systems(FACTS), custom power devices and uninterruptible power supplies(UPS). The conventional two-level inverter synthesize voltage waveforms with high harmonics current, high dv/dt stress on connected equipment. To improve output wave form quality, the switching frequency has to be raised which causes additional switching losses. For high voltage induction motors, there are several approaches for realizing high voltage and high power inverters. Multi level voltage source pwm inverters are recently showing growing popularity because of easy sharing of large voltage between the series devices and lower THD in output voltage compared to two-level inverter.
Новинка

3549 руб.

In this book an attempt has been to circuit modeling and simulation of dynamic voltage restorer (DVR) using cascaded five level inverter. However, under input disturbances noise is present in the response characteristics. Multilevel cascade inverter with separate dc sources has been proposed for sensitive load. Simulation results have shown that with control strategy that operate the switches at fundamental frequency. These inverters have low total harmonic distortion (THD) and high efficiency. The main advantages of using multilevel inverters for sensitive load is given as follows: It is suitable for high-voltage and high –current applications It has higher efficiency because the devices can be switched at a low frequency. NO EMI problem exists. No charge unbalance problem results when the converters are in either charge mode (rectification) or drive mode (inversion). This book is to improve the output voltage response in dynamics and steady state operation inverter. In this work leads to modeling and simulation of dynamic voltage restorer using cascade five level inverter to improve the voltage quality due to disturbances in supply system and to reduced hamonics.
Новинка

4839 руб.

All Digital Phase Locked Loops (ADPLLs) have become more attractive because they yield better testability, programmability, stability, and portability over different processes and the ADPLLs can reduce the system turn around time. Phase-locked loop mechanisms may be implemented as either analog or digital circuits. Both implementations use the same basic structure. The implemented ADPLL has two operation modes which are frequency acquisition mode and phase acquisition mode. In frequency acquisition mode, the ADPLL achieves a fast frequency locking via the proposed feed-forward compensation algorithm. In phase acquisition mode, the ADPLL achieves a finer phase locking.
Новинка

4839 руб.

This work illustrates use of different Pulse Width Techniques for a three phase voltage source inverter using Matlab Simulink software. These techniques help in reducing harmonic content in power supply as well as in controlling output voltage and frequency. The techniques which we have demonstrated are Multiple PWM, Sinusoidal PWM (SPWM), Trapezoidal PWM, Staircase PWM, 60° PWM and Third Harmonic PWM. Though these techniques are very good at reducing lower order harmonics, efficiency of an inverter can’t be effectively increased due to the presence of higher order harmonics. To eliminate these harmonics, a filter is designed.
Новинка

3549 руб.

In This book use for Uninterruptible power supplies (UPSs) are widely used to supply critical loads, such as airline computers and life-support systems in hospitals, providing protection against power failure or anomalies of power-line voltage.In general, there are two types of traditional single phase UPSs. The first one couples a battery bank to a half or full-bridge inverter with a low-frequency transformer. In this type of UPSs, the ac output voltage is higher than that of the battery bank; thus, a step-up transformer is required to boost voltage. Due to the presence of the step-up transformer, the inverter current is much higher than the load current, causing high current stress on the switches of the inverter. The transformer also increases the weight, volume, and cost of the systemIn this type of UPSs, the additional booster is needed, leading to high cost and low efficiency. The controlling of the switches in the booster also complicates the system. The dead time in the pulse width-modulation (PWM). The proposed method is also implemented on hardware by using power electronic devices such as MOSFET and PIC controller for production of control signals.
Новинка

4839 руб.

Phase angle measurement between two AC waveform having same frequency is needed in various applications like 3-phase transformer connection,CT and PT installation,Power factor determination. Conventional phase angle meters are bulky and costly.A new method for measuring phase angle using a digital PLL is proposed with operating frequency range of 20Hz to 1kHz. This design also has lag/lead identification feature and is cost effective.The phase angle meter involves phase detection using PLL, frequency to voltage conversion, calibration and display.A regulated power supply and a phase shifter circuit are also designed to test the phase angle meter.A 3 1/2 digit LED display panel meter is used to display the final measured phase difference between two AC waveforms fed as input.
Новинка

9087.46 руб.

Introducing a new, pioneering approach to integrated circuit design Nanometer Frequency Synthesis Beyond Phase-Locked Loop introduces an innovative new way of looking at frequency that promises to open new frontiers in modern integrated circuit (IC) design. While most books on frequency synthesis deal with the phase-locked loop (PLL), this book focuses on the clock signal. It revisits the concept of frequency, solves longstanding problems in on-chip clock generation, and presents a new time-based information processing approach for future chip design. Beginning with the basics, the book explains how clock signal is used in electronic applications and outlines the shortcomings of conventional frequency synthesis techniques for dealing with clock generation problems. It introduces the breakthrough concept of Time-Average-Frequency, presents the Flying-Adder circuit architecture for the implementation of this approach, and reveals a new circuit device, the Digital-to-Frequency Converter (DFC). Lastly, it builds upon these three key components to explain the use of time rather than level to represent information in signal processing. Provocative, inspiring, and chock-full of ideas for future innovations, the book features: A new way of thinking about the fundamental concept of clock frequency A new circuit architecture for frequency synthesis: the Flying-Adder direct period synthesis A new electronic component: the Digital-to-Frequency Converter A new information processing approach: time-based vs. level-based Examples demonstrating the power of this technology to build better, cheaper, and faster systems Written with the intent of showing readers how to think outside the box, Nanometer Frequency Synthesis Beyond the Phase-Locked Loop is a must-have resource for IC design engineers and researchers as well as anyone who would like to be at the forefront of modern circuit design.
Новинка

4839 руб.

Solid state power frequency changers are used for various purposes.The usual practice to get variable frequency power source is to use rectifier-inverter combination.Unfortunately the conventional diode/thyristor bridge rectifiers at the input side cause several problems such as:low input power factor,considerable harmonic distortion of ac currents and harmonic pollution on grid. The PWM rectifier is a preferred choice for providing ac to d.c conversion,due to its capability of input p.f regulation,line harmonic current mitigation,d.c voltage control and bidirectional power flow.In this thesis work,the theory behind a three phase PWM rectifier has been studied.a controller is designed to regulate the output voltage and input power factor.The entire system with its controller is modeled and simulated in MATLAB-simulink to verify the effectiveness of the proposed control strategy,to set the controller gains exactly to ascertain certain ratings of few hardware implementation.In this thesis work,real time simulation of a three phase PWM rectifier system with the proposed control strategy has been done using FPGA.
Новинка

9618.11 руб.

This book presents a unified frequency-domain method for the analysis of distributed control systems. The following important topics are discussed by using the proposed frequency-domain method: (1) Scalable stability criteria of networks of distributed control systems; (2) Effect of heterogeneous delays on the stability of a network of distributed control system; (3) Stability of Internet congestion control algorithms; and (4) Consensus in multi-agent systems. This book is ideal for graduate students in control, networking and robotics, as well as researchers in the fields of control theory and networking who are interested in learning and applying distributed control algorithms or frequency-domain analysis methods.
Новинка

4839 руб.

In this project, Verilog HDL is used for the implementation due to its compatibility with pure digital hardware like FPGA’s. The Digital PLL is simulated and verified on FPGA to experience its advantages. The circuit comprises of a phase detector, loop filter, Numerically Controlled Oscillator (NCO), and two clock dividers. The circuit was stabilized to produce the frequency in the audio frequency range of 9.7 KHz. This agreed with the classical phase-locked loop model for the system. The stable long-term frequency clock was verified on the FPGA to generate the required locking frequency. The DC logic synthesis and a new synopsis low power flow was experimented for back annotation and to obtain the maximum possible operating frequency and area, timing and power estimation.
Новинка

5890 руб.

Direct implementation of Constant Flux Control of Induction Motor is difficult due to the lumped nature of winding parameters. Engineers have tried to solve this problem by using Volts/Hertz control which permits the indirect control of flux. To make full use of the motor torque capability at start and low speed, a modified Volt/Hertz control strategy which utilises low frequency boost-voltage is developed in this book. This, unlike the basic Volts/Hertz control, provides a boost-voltage at low frequencies thereby compensating for the stator impedance drops, offering constant flux operation and maximum motoring torque from zero to rated speed. This modified strategy is applied in the closed loop control of Induction Motor using Six Step Inverter. The results obtained show that variable voltage and frequency control allows simultaneous realization of good running and transient performances from squirrel cage induction motor which, inherently, is not capable of variable speed operation. All MATLAB/SIMULINK files used in realizing these results are included as appendix. The book is highly recommended for graduate level teaching and research in the area of Electric Machines and Drives
Новинка

5790 руб.

With rapid development in the area of RF and wireless communication, the interest in frequency synthesizers has grown rapidly in the last few years. Frequency synthesizer is used for local oscillator (LO) generation. In this thesis, our aim is to explore high-frequency low-power LO generation in CMOS technology. We focus on three most power-hungry blocks in a frequency synthesizer, which dominate the total power consumption due to their high-frequency operation, namely voltage-controlled oscillator (VCO), frequency divider and frequency multiplier, as these circuits are the bottleneck to achieve the above mentioned aim. Through reducing their power consumption, the total power consumption of the frequency synthesizer can be reduced significantly. Moreover, the phase noise of the frequency synthesizer is significantly dependent on the VCO and the frequency multiplier. These novel ideas are implemented in a 24-GHz frequency synthesizer. These designs should help those IC designers, who may be considering improving the performance of transceiver.
Новинка

6026 руб.

The demand for sophisticated frequency converters in the industry has recently increased. Hence, the tools for simulation and performance verification of such converters or control systems which embedded them are also needed to save both money and time. The book describes the implementation of fully operating simulink model of the high voltage frequency converter PowerFlex7000. The model is thoroughly tested in several speed and torque regulations with induction (asynchronous) machines of various power and load characteristics. The comparison between scalar frequency converters is also made. The designed model focuses on the overall behavior; therefore; it offers a unique and flexible tool for interfacing the model of the converter with mechanical, electrical or any other model and hence allowing simulation of complex control systems. The book could help anyone who deals with design, simulation and performance verification of control systems where either PowerFlex7000 or any other vector control based frequency converter is used.
Новинка

5790 руб.

In this study, we define phase derivatives of analytic signals through non-tangential boundary limits, and consequently raise a new type of derivatives called Hardy-Sobolev derivatives for signals in the related Sobolev spaces. We prove that signals in the Sobolev spaces have well-defined phase derivatives that reduce to the classical ones when the latter exist. Based on the study of several types of phase derivatives and their properties, we mainly work on the following three subjects: (1)We extend the existing relations between the instantaneous frequency and the Fourier frequency and the related ones for smooth signals to those in the Sobolev spaces. (2) Based on the phase derivative theory and the recent result of positivity of phase derivatives of boundary limits of inner functions the theoretical foundation of all-pass filters and signals of minimum phase is established. Both the discrete and continuous signals cases are rigorously treated. (3) We study a particular type of time-frequency distribution exclusively suitable for mono-components, called transient time-frequency distribution(TTFD). For multi-components we carry on a corresponding study.
Новинка

6690 руб.

Modern cellular phones and base stations have to serve a multitude of wireless communication standards with each standard using different frequency bands. For such applications, a universal programmable hardware is desirable which is often referred to as software-defined radio (SDR). This book describes agile frequency synthesizers representing key building blocks for an SDR transceiver. In this work, an innovative frequency generation scheme is derived to provide a multi-octave tuning range with very low phase noise and low spurs. A PLL phase noise model including a nonlinear phase detector is thoroughly discussed. Design techniques for low phase noise VCOs with mixed analog/digital tuning are presented. Further, the book investigates both single-loop and dual-loop PLL architectures in fractional-N synthesizers. An unconventional two-transistor based charge pump in a dual-loop PLL improves phase detector linearity and reduces charge pump noise. This results in a low in-band phase noise similar to an integer-N synthesizer. Finally, the book presents the design of fully integrated integer-N and fractional-N frequency synthesizers with detailed measurement results.
Новинка

3549 руб.

Cooperative communication is a novel technique which is effective to alleviate the effects of channel fading exploiting diversity gain achieved by cooperation nodes and relays. Orthogonal frequency division multiplexing (OFDM) converts a frequency selective fading channel into a collection of parallel flat fading sub channels, but sensitive to frequency offset and phase noise. The carrier frequency offset and phase noise cause loss of orthogonality among subcarriers resulting to inter carrier interference. The integrating of OFDM and cooperative communication exploit relay for high data rate transmission of signals over wireless channel. Our motivation behind this book is to present the performance of OFDM based cooperative communication system incorporating frequency offset and phase noise for the Amplify and Forward (AF) and Decode and Forward (DF) over Nakagami-m fading channel. Detailed mathematical derivation is carried out for signal to noise plus interference ratio and average bit error rate for proposed scheme. Numerical results are provided to show the significant improvement of DF in OFDM based cooperative communication due to same frequency offset and phase noise.
Новинка

4929 руб.

Most of researchers studied a Shunt Active Power Filters (SAPF) based on conventional two-level inverters with conventional controllers that requires a complex and a complicated mathematical model. In order to overcome this problem a Hysteresis band controller based diode clamped multilevel inverter is implemented and extended to a five level shunt active power filter. This research investigates the design of Hysteresis band controller biasing multilevel inverter to works as Shunt Active Power Filter (SAPF). Making use of the multilevel inverter advantages of less total harmonic distortion and reduced semiconductor ratings compare with conventional inverter. A three phase 5- level diode clamped Multi-Level Inverter (5-LDCMLI) uses as a voltage source inverter (VSI). The Hysteresis band controller determines the optimum switching pattern needed for the inverter to compensate the current harmonics and the reactive power of the load. The inverter is investigated by this study using MATLAB Simulink.
Новинка

7890 руб.

The Turkish power system suffers from frequency oscillations with 20 – 30 seconds period. This thesis focuses on solving the frequency control problem within the Turkish power system. Design criteria and requirements related to primary and secondary control are elaborated in order to establish the frequency stability of the isolated Turkish power system and to fulfil the requirements of the extended system after the interconnection of Turkey with the European system. On 18 September 2010 the Turkish power system was synchronized with the interconnected power systems of Continental Europe.
Новинка

7359.51 руб.

An in-depth look at the theory and applications of frequency stability An understanding of the acquisition of stable frequency is essential for anyone who needs to solve noise problems in wireless communications. This book offers a thorough introduction to the principles and applications of frequency stability, arming practicing engineers with the tools they need to minimize noise in systems and devices that affect everyday communications for millions of people. With an emphasis on both practical and scientific points of view, Frequency Stability: Introduction and Applications examines frequency and time fluctuations in resonators, as well as the stability of both standard and practical microwave oscillators. It explains noise properties of building circuit blocks, introducing time domain properties and how they relate to noise spectral densities. Including a special chapter devoted to the design and properties of phase locked loops—a crucial topic for frequency synthesizers—the book also: Examines in detail L/F noise, showing how power losses in the propagation material extend over a long period of time Covers sapphire, optoelectronics, MW, and ring oscillators with the discussion of noise in delay-line oscillators with lasers Offers an extended treatment of phase noise in semiconductors and amplifiers based on Van der Ziel investigations Emphasizes the modified Allan variance in the time domain, including exact computations Outlines the relationship between resonator frequency and output phase noises via the feedback theory Featuring numerous tables with actual data, Frequency Stability: Introduction and Applications is an invaluable guide for engineers wishing to rein in acoustic and electromagnetic interference in modern communications.
Новинка

4839 руб.

This book contents an elaborate analysis on the SPWM (Sine Pulse Width Modulation) Boost Inverter especially for the grid connected PV power system. Reactive power control strategy of Boost Inverter at the inverter side has also been studied. By changing the modulation index of the Boost Inverter the output parameters have been varied. A range of modulation index has also been prescribed within which the percentage of THD (Total Harmonic Distortion)is in a tolerable range according to the IEEE standard 519. Moreover, a rigorous analysis on a set of different parameters along with the simulation results has been made and compared to investigate the proper characteristics of this device.
Новинка

5870 руб.

Neurological diseases in newborns are usually first revealed by seizures, which are characterised by a synchronous discharge of a large number of neurons. Failure to control seizures may lead to brain damage or even death. Neonatal EEG seizures can have signatures in both low frequency (lower than 10 Hz) and high frequency (higher than 70 Hz) areas. The seizures detection techniques proposed in the literature concentrated on using either low frequency or high frequency signatures but not both simultaneously. These methods tend to miss the seizures that reveal themselves only in one of the two frequency areas. The author proposed a detection method that uses seizure features in both low and high frequency areas.
Новинка

4839 руб.

This thesis is dedicated to measurement of optical frequencies with applications in metrology. The frequency/time interval is the best measurable quantity. The invention of the femtosecond frequency comb technique greatly simplified linking the radio-frequency and the optical-frequency standards. A primary wavelength standard for optical communications was developed in the first part of this work: the distributed feedback (DFB) laser diode was frequency stabilized to sub-Doppler spectral line of acetylene at ~1540 nm and its research, investigation of properties and absolute frequency measurements are described. The implementation and testing of commercial femtosecond comb makes second part of this work. Software for online frequency evaluation, tests of counting quality and frequency stabilization of the comb to optical frequency standard - iodine stabilized Nd:YAG laser - are described.
Новинка

5490 руб.

Communication is the key for controlling solar photo-voltaic systems. Nowadays, wireless is the technology used to control solar systems. For cost and reliability purposes, a wired communication technology is to be used. The existing power wires will be exploited to transmit data. The aim of this book is to investigate the integration of power line communications and low-voltage solar photo-voltaic systems. Binary frequency shift keying techniques and the Zero-Crossing methods are studied and implemented to achieve a transmission at low data rate over the H-bridge inverter.
Новинка

4929 руб.

In this book, a study of Metamaterials for RF and microwave applications is presented. Several novel designs of planar Metamaterials are proposed and their electromagnetic properties are investigated with the help of FEM based software package.The proposed structure possesses artificial magnetic conductor like response at a particular frequency which is lower than UCPBG and mushroom like structure. The novel structure also possesses very wide band gap, approximately equal to 4.5 GHz, for surface waves in X- band of frequency. The effect of various structure parameters such as substrate permittivity, substrate thickness, patch size and gap between adjacent unit cells of Metamaterial slab, on reflection phase characteristic, is investigated. These investigations provide information about how to control the band width and resonant frequency of Metamaterial by varying these parameters. The proposed structure is modified to exhibit negative refractive index in some frequency region matched to free space.The Metamaterial slab behaves like DNG medium in a specified frequency region.
Новинка

1259 руб.

Global frequency
Новинка

5490 руб.

Increasing energy demand with rapid depletion of limited fossil fuel reserves has led to increase in global demand for clean energy sources and its harnessing technologies with higher efficiency and reliability. Solar energy has proved to be very promising in its usefulness as an effective, inexhaustible and environmental friendly source of energy. Building Integrated Photovoltaic (BIPV) technology amongs various methods of solar energy harvesting is a good solution to ensure better utilization of solar energy in rural and/or urban areas having many residential and commercial buildings. Each BIPV panel is connected to grid through an individual micro-inverter eliminating the problems of partial shading, dc arcs and space requirements etc. which is associated with conventional inverter technologies. The book deals with design and development of dual stage micro-inverter, where in dc-dc boost conversion is achieved using phase modulation topology. Selected topology and developed control schemes are validated in PSIM® simulation environment. An experimental setup is developed with TMS320F28335 Digital Signal Controller (DSC) as embedded platform to validate the control strategies.
Новинка

4178.9 руб.

An ideal resource for students, industrial engineers, and researchers, Signal Processing with Free Software Practical Experiments presents practical experiments in signal processing using free software. The text introduces elementary signals through elementary waveform, signal storage files and elementary operations on signals and then presents the first tools to signal analysis such as temporal and frequency characteristics leading to Time-frequency analysis. Non-parametric spectral analysis is also discussed as well as signal processing through sampling, resampling, quantification, and analog and digital filtering. Table of Contents: 1. Generation of Elementary Signals. Generation of Elementary Waveform. – Elementary Operations on the Signals. – Format of Signal Storage Files. 2. First tools of Signal Analysis. Measurement of Temporal and Frequency Characteristics of a Signal. Time-Frequency Analysis of a Signal. 3. Non-parametric Spectral Analysis. 4. Signal Processing. Sampling. – Resampling. – Quantification. – “Analog” Filtering. Digital Filtering
Новинка

12934.7 руб.

Presents simulation techniques that substantially increase designers' control over the oscillationin autonomous circuits This book facilitates a sound understanding of the free-running oscillation mechanism, the start-up from the noise level, and the establishment of the steady-state oscillation. It deals with the operation principles and main characteristics of free-running and injection-locked oscillators, coupled oscillators, and parametric frequency dividers. Analysis and Design of Autonomous Microwave Circuits provides: An exploration of the main nonlinear-analysis methods, with emphasis on harmonic balance and envelope transient methods Techniques for the efficient simulation of the most common autonomous regimes A presentation and comparison of the main stability-analysis methods in the frequency domain A detailed examination of the instabilization mechanisms that delimit the operation bands of autonomous circuits Coverage of techniques used to eliminate common types of undesired behavior, such as spurious oscillations, hysteresis, and chaos A thorough presentation of the oscillator phase noise A comparison of the main methodologies of phase-noise analysis Techniques for autonomous circuit optimization, based on harmonic balance A consideration of different design objectives: presetting the oscillation frequency and output power, increasing efficiency, modifying the transient duration, and imposing operation bands Analysis and Design of Autonomous Microwave Circuits is a valuable resource for microwave designers, oscillator designers, and graduate students in RF microwave design.
Новинка

4839 руб.

The project suggests the development of a low cost fuel cell inverter system. The approach consists of a three-terminal push-pull inverter to boost the fuel cell voltage. High-frequency ac link conversion offers a possible way to reduce the number of power stages, in the form of a cycloconverter. The design minimizes overall system cost including energy storage and management. The design provides low-ripple current-controlled interfacing to the fuel-cell stack, an intermediate-voltage battery energy storage buffer, and an ac-link output inverter. The circuit is based on square-wave cycloconverter technology, combined with a simple approach that produces a patent-pending “PWM cycloconverter” modulation process. Modulation technique includes multiple carrier PWM which is a direct extension of conventional PWM. The approach keeps the number of stages and magnetic elements low while providing galvanic isolation. The design provides excellent performance with a minimum filter components and a simple control.
Новинка

4839 руб.

It is necessary for the Power load operators and regulators to manage distribution services efficiently to maintain reliability of the power system. Frequency regulation is one of the distribution services to be supplied by the electricity market participants. The only way to regulate frequency is to maintain the balance between demand and supply in real time. In India, it is achieved through a regulatory approach. In this Paper, an investigation is made on Free Governor Mode of Operation to demonstrate Frequency Regulation by adopting Free Governor Mode of Operation. Simulation is a powerful technique used to predict the performance or analyze the behaviour of any closed loop control system. It is also used to tune the controller gains or to design a control system. Development of mathematical model is the first step in the simulation study. Matlab and Simulink of Mathworks Inc. are widely used in the academic and industrial world. A simple model of a speed governing system of the steam turbine is taken for illustrating the dynamic simulation.
Новинка

7256 руб.

This book consists of six publications and an overview of the research topic. The research described in this book concentrates on the design of phase-locked loop radio frequency synthesizers for wireless applications. In particular, the focus is on the implementation of the prescaler, the phase detector and the chargepump. This work reviews the requirements set for the frequency synthesizer by the wireless standards, and how these requirements are derived from the system specifications. These requirements apply to both integer-N and fractional-N synthesizers. The work also introduces the special considerations related to the design of fractional-N phase-locked loops. Implementation alternatives for the different building blocks of the synthesizer are reviewed, and new topologies for the phase detector and the chargepump as well as improved topologies for high speed CMOS prescalers are introduced. The experimental results show that the presented topologies can be successfully used in both integer-N and fractional-N synthesizers with state-of-the-art performance. Finally, additional considerations of integrating a frequency synthesizer into a full transceiver chip are discussed
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8363 руб.

This thesis deals with the design and analysis of control system structures for electric drives equipped with permanent-magnet synchronous machines (PMSMs) in automotive applications. Sensorless control is considered and a speed and position estimator of phase-locked loop type is analyzed thoroughly. The theory of loss minimization by means of control is applied to a PMSM drive intended for propulsion in a hybrid electric vehicle. The study shows that the additional inverter losses reduce the potential to minimize the total losses considerably. A review of fault-tolerant PMSM drives is presented and control algorithms are proposed for achieving sensorless control, closed-loop field-weakening control, and maximum utilization of the inverter voltage for a drive that, for redundancy, adopts an additional inverter leg connected to the machine neutral point. The impact of various electrical faults in a vehicle equipped with in-wheel motors and individual steering actuators is also investigated. Here, it is shown that vehicle stability can be maintained with only minor displacements using a closed-loop path controller and an optimal approach to allocate tire forces.
Новинка

4839 руб.

High-performance digital systems use clocks to sequence operations and synchronize between functional units and between ICs. Clock frequencies and data rates have been increasing with each generation of processing technology and processor architecture. Phase locked-loops (PLLs) are widely used to generate well-timed on-chip clocks in high-performance digital systems. A PLL is a closed loop frequency system that locks the phase of an output signal to an input reference signal. PLL‘s are widely used in computer, radio, and telecommunications systems where it is necessary to stabilize a generated signal or to detect signals. The term lock refers to a constant or zero phase difference between two signals. The signal from the feedback path is compared to the input reference signal,until the two signals are locked. If the phase is unmatched, this is called the unlocked state, and the signal is sent to each component in the loop to correct the phase difference. These components consist of the Phase Frequency Detector (PFD), the charge pump (CP), the low pass filter (LPF), the voltage controlled oscillator (VCO) and divide by counter.
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Новинка

Новинка

23910 руб.

Новинка

35870 руб.

Новинка

4839 руб.

The performance of a fractional-N frequency synthesizer is degraded due to the presence of unwanted spurious tones (spurs) in the output spectrum. The Digital Delta-Sigma Modulator can be directly responsible for the generation of spurs because of its inherent nonlinearity and periodicity. In this booklet we have predicted that specific nonlinearities in a fractional-N frequency synthesizer produce spurs at well-defined frequencies even if the output of the DDSM is spur free. Different spur free DDSM architectures have been investigated for the analysis of spurious tones in the output spectrum of fractional-N frequency synthesizers.
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Новинка

6390 руб.

This book does the following: 1- Study different UPS systems, and related subjects such as power electronics, and microcontroller unit. 2- Design and implementation of hardware circuits using microcontroller to get UPS inverter system meets the required performance and do the specified control. 3- Apply classical controllers such as PD, PID, and SMC using microcontroller and simulate these systems on simulation program, after that apply these controllers on the real system, and get experimental results. 4- Apply fuzzy logic control, and nonlinear PID-fuzzy control on UPS inverter system and simulate on simulation program, after that apply these controllers on the real system, and get experimental results.
Новинка

4839 руб.

Well-being in our modern society depends on the availability of electrical power. However, the observed climate change and increasing prices of fossil fuels make the annually growing need for energy challenging to be satisfied. Photovoltaic (PV) power generation seems to be one of the most promising alternatives for fossil fuels, because it has been estimated that utilizing 1 % of global sunlight with a conversion efficiency of 1 % would be enough to cover our energy needs. The PV power systems are interfaced to the utility grid by single or three-phase inverters. Robust and safe operation of these inverters can be guaranteed by proper power-stage and control system design. In control engineering, the control system is usually tuned by using the small-signal model of the system. This book presents a small-signal model that can be used to design a robust and stable control system for a three-phase PV inverter. This book can be used as a self-study material or as an additional source of information by researchers and design engineers dealing with power electronics and control issues in PV applications.
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6026 руб.

The Enhanced Adaptive Frequency Hopping (EAFH) mechanism improves the performance of frequency hopping-based wireless personal area networks (WPANs) under frequency-static and frequency-dynamic interference. The proposed mechanism monitors the overall packet error rate (PER) of the system to determine the right number of channels to be excluded from the hopset. Then based on the PER of individual channel, it decides whether to exclude a certain channel or not. EAFH could provide much higher throughput while still maintaining reasonably good channel occupancy.
Новинка

4839 руб.

The usual method for time-frequency representation using Short Time Fourier Transform or Spectrogram does not give precise time frequency information; hence the analysis of signal using them is not much easy. The Wigner Ville Distribution (WVD) can be used for a time-frequency representation of signals with a very good resolution in time and frequency domain. WVD has many features which make them suitable for applications in transient signal detection. This book talks about different time frequency signal representations including Wigner Ville Distribution and presents some methods to reduce the cross terms in WVD. The book also describes some important applications of the variants of WVD in the world of signal processing. This book will help a student or a researcher to learn about time frequency representations and to understand how to use them in a variety of applications.
Новинка

3549 руб.

In sensorineural hearing loss due to poor frequency resolution, the high frequency amplification leads to distortion thereby resulting in poorer speech discrimination and understandability. The present study explains about the nonlinear frequency translation hearing aid show better speech performance compared to conventional hearing aids. There was a significant difference between speech recognition performances in the two hearing aid settings. A slight overall improvement can be noted for nonlinear frequency translation hearing aid than for conventional one.
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4929 руб.

In the tremendous growth of wireless handheld devices, low power consumption becomes a major consideration in radio frequency integrated circuit (RFIC) designs. This book introduces a multistage voltage controlled ring oscillator. The proposed structure uses 45 nm CMOS Technology in cadence. PSS analyses are performed in order to determine the frequency of oscillation and the influence of parameters such as supply voltage, temperature or load capacitance over the oscillation frequency. A transient analysis is performed to illustrate the effects of the parasitic parameters over the oscillation frequency. Ring oscillators with different number of stages like 7, 9 and 11 were designed successfully and their performance parameters are discussed in great detail and compared to reach to solutions to the challenges faced by the current Ring Oscillator technology. The challenges are phase noise, frequency jitter, period jitter, delay, jitter, total harmonic distortion (THD), transfer function etc. and are dealt appropriately in the system designs proposed for different number of stages. For example, a certain signal may have a phase noise of -80 dBc/Hz at an offset of 10 KHz.
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7790 руб.

A repetitive control method for output voltage control of a three phase uninterruptible power supply (UPS) with isolation transformer is investigated. In the method voltage control loop is employed in the stationary dq frame. The controller eliminates the periodic errors on the output voltages due to inverter voltage nonlinearity and load disturbances. The controller design and implementation details are given. The controller is implemented on a 5-kVA UPS prototype which is constructed in laboratory. Linear and nonlinear loads for balanced and unbalanced load operating conditions are considered. The steady-state and dynamic performance of the control method are investigated in detail. The theory of the control strategy is verified by means of simulations and experiments.
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3549 руб.

An FPGA controlled solar inverter proto-type for home applications has been presented in this paper. It is considered as an appropriate design for the developing countries. Even though the grid cut-off happens very frequently here, they don’t provide the houses with any sufficient backup power supply. The operation stages and characteristics of the proposed converter are presented. The proposed digital control scheme for solar inverter has been implemented.
Новинка

4839 руб.

Hi this is Kranthi Sale, Completed my Bachelors(2004-2008) & Masters(2008-2010) from "ALI YAVAR JUNG NATIONAL INSTITUTE FOR THE HEARING HANDICAPPED". I Worked as a Audiologist and Clinical Specialist in Shravya Speech and Hearing center,Hyderabad and at present I am working in AYJNIHH,SRC as a Speech Pathologist.This book is based on the original work done by me in my Masters. It explores the utility of GAP detection test in Cochlear Implant Recipients.The work shows that there is frequency specific difference in responses of individuals with Cochlear Implants.This marked difference at low frequency is observed because the auditory filter seems to play a role in determining the form of the results for the standard-and reversed phase conditions, Gap thresholds estimated from the preserved-phase condition do not show a strong effect of center frequency, except at very low frequency (200 Hz below). I acknowledge Dr.S.G.R.Prakash and Mr.B.Shiva Prasad for their immense support.
Новинка

9286.45 руб.

This book is an all-in-one resource on the development and application of variable frequency transformers to power systems and smart grids. It introduces the main technical issues of variable frequency transformers (VFT) systematically, including its basic construction, theory equations, and simulation models. Readers will then gain an in-depth discussion of its control system, operation performance, low frequency power oscillation, and technical economics, before proceeding to practical implementation and future developments. The related concepts of energy revolution, third generation grids, and power system interconnection are discussed as well. The first, comprehensive introduction to variable frequency transformers (VFT) An in-depth look at the construction of VFT, with simulations and applications Demonstrates how to assess the control system and overall system performance Analyses future developments, energy revolution and power system interconnections Variable Frequency Transformers for Large Scale Power Systems is a timely overview of the state of the art for VFT as it is increasingly adopted in smart grids. It is intended for engineers and researchers specializing in power system planning and operation, as well as advanced students and industry professionals of power engineering. How to acquire the input frequency from an unlocked state A phase locked loop (PLL) by itself cannot become useful until it has acquired the applied signal's frequency. Often, a PLL will never reach frequency acquisition (capture) without explicit assistive circuits. Curiously, few books on PLLs treat the topic of frequency acquisition in any depth or detail. Frequency Acquisition Techniques for Phase Locked Loops offers a no-nonsense treatment that is equally useful for engineers, technicians, and managers. Since mathematical rigor for its own sake can degenerate into intellectual «rigor mortis,» the author introduces readers to the basics and delivers useful information with clear language and minimal mathematics. With most of the approaches having been developed through years of experience, this completely practical guide explores methods for achieving the locked state in a variety of conditions as it examines: Performance limitations of phase/frequency detector–based phase locked loops The quadricorrelator method for both continuous and sampled modes Sawtooth ramp-and-sample phase detector and how its waveform contains frequency error information that can be extracted The benefits of a self-sweeping, self-extinguishing topology Sweep methods using quadrature mixer-based lock detection The use of digital implementations versus analog Frequency Acquisition Techniques for Phase Locked Loops is an important resource for RF/microwave engineers, in particular, circuit designers; practicing electronics engineers involved in frequency synthesis, phase locked loops, carrier or clock recovery loops, radio-frequency integrated circuit design, and aerospace electronics; and managers wanting to understand the technology of phase locked loops and frequency acquisition assistance techniques or jitter attenuating loops. Errata can be found by visiting the Book Support Site at: http://booksupport.wiley.com