PWM

Active filtering of electric power has now become a mature technology for harmonic and reactive power compensation in two-wire (single phase), three-wire (three phase without neutral), and four-wire (three phase with neutral) ac power networks with nonlinear loads. This paper presents the simulations of Field programmable gate array (FPGA) - based single phase hybrid active power filters of two different configurations using Xilinx system generator. The former one with the hybrid combination of series active power filter and shunt passive filter is designed to mitigate the distortions in source voltage and source current due to the voltage source type harmonic load and the latter one with the hybrid combination of shunt active power filter and shunt passive filter is designed to mitigate the harmonics in source current due to the current source type harmonic load.

A digital current-mode controller for dc-dc converters is introduced. The current-mode loop is sensorless, relying on constants and internal loop states; removing the need to sense controlled voltages or currents for the inner loop. Furthermore, a fast current-mode control mechanism is implemented by utilizing dead-beat control. The resulting controller is robust and surprisingly uncomplicated. It is well suited to VLSI integration in a low geometry process. An interesting aspect of this control scheme is that it facilitates the application of a low resolution PWM.

inverters is proposed. The closed-loop system uses the two-axis components of the transformed line-to-line voltage vectors as the control variables. In its linear control range, the PWM method includes two operating modes, namely, low and high references. At high references' mode, the output voltage is generated by switching among four vectors instead of three to improve the waveform generation. The proposed system has a linear control range 15.5% wider than conventional phase control methods. Furthermore, the control range can be easily expanded beyond the higher linear controllable range up to the square waveforms without suddenly increasing the waveform distortion. Therefore, the fundamental component of the output voltage can be smoothly and continuously controlled from zero up to square waveforms. The control circuit includes a hysteresis controller that is capable of stabilizing the neutral point potential variations within fixed limits during steady and transient states. The control method also offers high performance and fast response. Computer simulations and experimental results on a laboratory-tested motor drive are given to validate the proposed control scheme.

The aim of this work, to design an appropriate Kalman filter (KF) with optimal gain as well as a two degree of freedom compensator for the DC motor, verify the stability of the proposed algorithm and the noise sensitivity are carried out. The design of the present algorithm is to combine both 2DOFPID controller with the optimal gain obtained by designing a (KF) to obtain better performance. The sensor noise covariance has been precisely chosen to design of the (KF) through state space model of DC motor. Controllability and observability are the main issues in the analysis of a system before deciding the best control strategy to be applied, or whether it is even possible to control or stabilize the system. Static parameters of a permanent magnet DC motor speed control with external load torque is simulated. The closed loop system and a two degree of freedom (2DOF) PID controller designed on the basis of the robust response tuning method. However, both no load and load current , speed and torque obtained. The (KF) speed response with the error between actual speed and estimated speed obtained. The robustness of the proposed algorithm checked through a 2DOF PID controller development. Comparison between classical PID speed response with 2DOF PID speed response carried out. The senses against the noise are approved as well as the torque and current in load and no load has been compared. The simulated results of the proposed algorithm improved performance operation and shows the effectiveness of the compensator new technique compared to the classical one.

This paper describes a single-chip speech recognition system. It contains the speech functions of prompt, playback, speakerdependent speech recognition, suitable for the voice activated systems in toys, games, consumer electronics, office devices, etc. The chip is designed based on the SOC (System on Chip) philosophy and an 8-bit MCU, RAM, ROM, ADCIDAC, PWM, I/O ports and other peripheral circuits are all embedded in it. Software modules including control/communication, speech coding and speech recognition algorithms are implemented in an 805 1 compatible microcontroller core, resulting in the extremely low cost of the chip. The speech recognition adopts the template matching technique. It recognizes up to 20 phrases with an average length of 1 second and the recognition accuracy reaches more than 95% with the background SNR above IOdB. Speech coding uses Continuous Variablc Slope Deltamodulation (CVSD) algorithm. The bit rate is 16kbitsis.

An improved full-bridge ZVS PWM using a twoinductor rectifier dddc converter is presented in this paper. For this improved topology, the main devices are switched on under zero-voltage (ZVS) conditions using the energy stored in the secondary filter inductors. In addition, it utilizes the low leakage inductance of a coaxial winding transformer to reset the currents in the rectifier diodes and eliminate the secondary voltage spike. The two-inductor rectifier has only one diode conduction drop in addition to frequency doubling in the output capacitor. The secondary filter size in the proposed topology is rather small. The advantages of the new topology include a wide loa d range with ZVS, no lost duty cycle due to diode recovery, no secondary voltage spikes, in addition to high power density and high efficiency.

The paper describes the development of an electrically operated pneumatic fast-switching valve for pneumatic position control systems. The valve was designed and fabricated as an on–off valve with 2/2-way function and its characteristics were investigated. The detailed theoretical analysis and preliminary tests were carried out on the manufactured valve and showed that the switching time of the single stage valve

This paper presents an advanced three phase inverter topology the Z-Source Inverter and its control using microcontroller 89C52. Z-Source Inverter employs second order filter network at front end which provides unique buck-boost feature for inverter. Z-Source inverter can be controlled by any traditional PWM method. Here the modified maximum constant boost PWM method is utilized for Z-Source inverter control. The microcontroller 89C52 is used to generate PWM pulses and to control operation of Z-Source inverter. The complete hardware is designed to drive the three phase induction motor. The hardware design involves the design of control circuit, driver circuit, Z-Source network, main inverter bridge, power supply etc. The Z-Source inverter is implemented and tested to verify the Z-Source inverter concept. The desired three phase PWM signals are generated by using control circuit and detailed hardware results are presented.

Speed control of a machine is the most vital and important part in any industrial organization. This paper is designed to develop a four quadrant speed control system for a DC motor using microcontroller. The motor is operated in four quadrants i.e. clockwise, counter clock-wise, forward brake and reverse brake. It also has a feature of speed control. The four quadrant operation of the dc motor is best suited for industries where motors are used and as per requirement they can rotate in clockwise, counter-clockwise and also apply brakes immediately in both the directions. In case of a specific operation in industrial environment, the motor needs to be stopped immediately. In such scenario, this proposed system is very apt as forward brake and reverse brake are its integral features. Instantaneous brake in both the directions happens as a result of applying a reverse voltage across the running motor for a brief period and the speed control of the motor can be achieved with the PWM pulses generated by the microcontroller. The microcontroller used in this project is from 8051 family. Push buttons are provided for the operation of the motor which are interfaced to the microcontroller that provides an input signal to it and controls the speed of the motor through a motor driver IC. The speed and direction of DC motor has been observed on digital CRO. Microcontroller programming has been written in assembly language by using notepad and it has been converted in hex file by using micro vision Kiel. The burning of programming in the 8051 microcontroller chip has been done by using positron boot loader software.

Resumen-Se presenta la aplicación de un control digital utilizando un DSP, para controlar la velocidad de un motor de inducción trifásico en lazo cerrado mediante la técnica de control voltaje-frecuencia. También se presenta un panorama general de las técnicas 1 de control escalar y vectorial, analizando en detalle la técnica escalar voltaje-frecuencia.

Abstract-This project suggest a sine-wave modulation technique is to achieve a low total harmonic distortion of Buck-Boost converter connected to a changing polarity inverter in a system. The suggested technique improves the harmonic content of the output. In addition, a proportional-resonant Integral controller is used along with harmonic compensation techniques for eliminating the DC component in the system. Also, the performance of the Proposed controller is analyzed when it connecting to the converter. The design of Buck-Boost converter is fed by modulated sine wave Pulse width modulation technique are proposed to mitigate the low order harmonics and to control the output current. So, that the output complies within the standard limit without use of low pass filter.

The project reveals speed control of DC motor using PWM technique. In present days the power semiconductor devices have completely revolutionized the control of drives especially in the area of control usage of thyristors igbt’s power MOsFET etc. was increased. The digital circuit can be interfaced to microcontroller. So that speed can be controlled by Microcontroller. This project is mainly concerned on design and implementation of bidirectional dc motor speed by using microcontroller ATmega16 and PROTEUS VSM software. Through the keypad we can achieve any speed at the time of running & also in initial starting period. Pulse Width Modulation (PWM) technique is used which is generated using microcontroller Atmega16 the PWM signal generated will drive the motor driver circuit. By varying the duty cycle the voltage across the motor is varied. PROTEUS VSM software is used to provide a graphic user interface (GUI) for the user.

In many remote or underdeveloped areas, direct access to an electric grid is impossible and a photovoltaic inverter system would make life much simpler and more convenient. With this in mind, this paper aims to design, and simulate PV inverter in proteus professional software. This inverter system could be used as backup power during outages, battery charging, or for typical household applications for rural especially. The principle is to adapt the output voltage of the solar module to the battery by using the technique of pulse width modulation (PWM). The sinusoidal pulse width modulated (PWM) waveform is generated from inverter in laboratory by 16 bit microprocessor through program developed using a novel technique of direct modulation strategy .The key features of the system are a true 50Hz, 230Vsinusoidal voltage output, a wide input range, and a power output of up to 350 watts. The overall goal is to design this system while minimizing component costs.. In addition, inverters in the lower price range typically lack most of the features. solar home lighting systems mostly comprises of solar panel, solar charger, battery & a inverter, The main motivation of this paper or the uniqueness of this project is to combine both the solar charger as well as inverter together to ATMEGA 32 RISC based which works up to 16MIBS which reduces the cost as well as the system becomes compact.

The objective of this paper is modeling and simulation of doubly fed induction generator (DFIG) and Permanent Magnet Synchronous Generator (PMSG) based Wind Energy Conversion System in PSCAD/EMTDC. This variable speed wind energy system has ac-dc converter which regulates the DC-link voltage at a constant value, and maintaining reactive power generation at a pre-determined level which is zero in this study. This paper also includes controlling of DFIG and PMSG at generator and grid side.

Many industrial applications require the use of power electronic devices, which in turn help in overcoming the problems of variable load and fluctuations that occur at the end of feeding. The current study emphasizes that the use of different electric power generation systems with industrial applications needs control devices to work on improving the power quality and performance of systems in which there is an imbalance in the voltage or current due to the change of loads or feeding from the source. The present study also presents a model of a transformer widely used in industrial applications and this work includes simulating a three-phase rectifier by MATLAB. There are four cases in this work HWR (uncontrolled and controlled) and FWR (uncontrolled and uncontrolled) with different loads (R, RL & RC) including full wave type AC/DC using six electronic transformer silicon control rectifier (SCRs) once as well as unified half wave using three electronic transformer silicon control rectifier (SCRs). Simulation results include input, output voltage, and current with the waveform.

This paper presents open loop speed control scheme for the speed control of a permanent magnet DC motor using an AVR Microcontroller. The microcontroller has been programmed to automatically vary the duty cycle of the H-bridge chopper depending upon the set/required speed of the motor. The chopper is driven by a high frequency PWM signal. Controlling the PWM duty cycle is equivalent to controlling the motor terminal voltage, which in turn adjust directly the motor speed. The PC interfacing has been done using serial port (DB9 Connector). Experimental results show that proposed system is suitable for different industrial applications such as trolley buses, subway cars, or battery-operated vehicles. interfacing. A 12V, 300W, 2400 rpm permanent magnet dc motor and 5v, 500mA regulated power supply has been used

This paper presents a predictive current control method and its application to a voltage source inverter. The method uses a discrete-time model of the system to predict the future value of the load current for all possible voltage vectors generated by the inverter. The voltage vector which minimizes a quality function is selected. The quality function used in this work evaluates the current error at the next sampling time. The performance of the proposed predictive control method is compared with hysteresis and pulsewidth modulation control. The results show that the predictive method controls very effectively the load current and performs very well compared with the classical solutions.

This paper involves designing a small scale battery charging system which is powered via a photovoltaic panel. This work aims at the usage of solar energy for charging the battery and optimizing the power of the system. Implementation is done using Artificial Neural Network (ANN) on FPGA. To develop this system an Artificial Neural Network is trained and its result is further used for the PWM technique. PWM pulse generation has been done using Papilio board which is based on XILINX Spartan 3E FPGA. The ANN with PWM technique is ported on FPGA which is programmed using VHDL. This able to automatically control the whole charging system operation without requirement of external sensory unit. The simulation results are achieved by using MATLAB and XILINX. These results allowed demonstrating the charging of the battery using proposed ANN and PWM technique.

In this paper, a survey on the characteristics of thermoresistive sensors [positive temperature coefficient (PTC) and negative temperature coefficient (NTC)] and their applications to measurement structures that use the electric equivalence principle, in special radiometers and anemometers, is presented. The dynamic responses of the architectures and the influence of the operational amplifier offset voltage on the instrument performance are discussed. Alternative architectures employing pulsewidth modulation (PWM) and sigma-delta analog-to-digital (A/D) converters are also shown.

The saturable inductor is employed in the fullbridge (FB) zero-voltage-switched (ZVS) pulsewidth-modulated (PWM) converter to improve its performance. The current and voltage stresses of the switches as well as parasitic oscillations are significantly reduced compared to those of the conventional FB-ZVS-PWM converter. The qualitative analysis is presented and is verified on a 500 KHz, 5 V/40 A converter.

An improved full-bridge ZVS PWM using a twoinductor rectifier dddc converter is presented in this paper. For this improved topology, the main devices are switched on under zero-voltage (ZVS) conditions using the energy stored in the secondary filter inductors. In addition, it utilizes the low leakage inductance of a coaxial winding transformer to reset the currents in the rectifier diodes and eliminate the secondary voltage spike. The two-inductor rectifier has only one diode conduction drop in addition to frequency doubling in the output capacitor. The secondary filter size in the proposed topology is rather small. The advantages of the new topology include a wide loa d range with ZVS, no lost duty cycle due to diode recovery, no secondary voltage spikes, in addition to high power density and high efficiency.

ÖZET AA indüksiyon motorları endüstriyel uygulamalarda yaygın olarak kullanılmaktadır. Bu motorlar genellikle değişken hızlarda çalıştırılmaktadırlar. AA motorların hızlarının kontrolu DA motorlarla kıyaslandığında, hızlarının ayarlanması daha karmaşıktır. Bu çalışmada, 3 fazlı bir indüksiyon motor hız kontrol devresi 8 bitlik bir mikrodenetleyici kullanılarak tasarlanmakta ve gerçekleştirilmektedir. Bir bakış tablosu kullanılarak, mikrodenetleyici tarafından üretilen PWM sinyalleri ile altı anahtarlı inverter kontrol edilmekte ve inverter çıkışındaki gerilimin etkin değeri ve frekansı değiştirilerek hız ayarı yapılmaktadır. Tasarlanan sistem, 8 bitlik bir mikrodenetleyici ile geliştirildiğinden, düşük maliyetli ve uygulanması kolay bir sistemdir.

Electric power steering (EPS) systems have attracted much attention for their advantages. The motor is one of the most important parts for EPS system. The EPS motor is operated by an H-bridge circuit bidirectionally with the PWM technique which results in static problem. The operating characteristics of EPS motor is analyzed and the deadband compensation was designed. The PWM waveform was generated and the deadband compensation testing was made. The results shown the good effects of deadband compensation which helps to meet the demands for faster speed, higher quality, and reduced power requirements in vehicles increasingly.

Comparative analysis between overlapping and non-overlapping operation modes for the PWM buck converter using the three-state switching cellThis article presents a comparative study involving a buck converter derived from the three-state switching cell in both operation modes, i.e. non-overlapping and overlapping modes, since it is well known in literature that several advantages can be addressed to topologies based on this approach. In the case of the mentioned converter, only part of the load delivered to the load flows through the controlled switches, so that operation at high-current high-power levels is possible. Besides, the design of reactive elements such as very autotransformer and filter inductor is performed for twice the switching frequency, with consequent reduction of size, weight and volume. Another clear advantage is that the area for which the converter operates in continuous conduction mode is wider than that for the discontinuous conduction mode in comparison with the so-called classical non-isolated buck converter. The operation of the converter, which was previously proposed in literature, is analysed considering the aforementioned modes in terms of the efficiency, and similar approaches for the non-isolated dc-dc conversion are also investigated.

In this paper modified single input multiple output dc-dc converters can be used to give a multi outputs. It has three outputs. That is low voltage power source is converted into high-voltage dc bus and middle voltage output terminals. It is coupled inductor based dc-dc converter. It has only one power switch with the properties of voltage clamping and soft switching. As a result, different level of output voltages, and multiple outputs, high efficiency power conversion and high step up ratio.

This project is mainly concerned on two DC motors speed, direction and operating period control system using three microcontrollers PIC 16F877A, one is the master and the two others are the slaves. It is a closed-loop real time control system, where rotary shaft encoder is coupled to the motor shaft to provide the feedback speed signal to the slave microcontroller. Pulse Width Modulation (PWM) technique is used to vary the voltage supplied to the DC motor armature(with fixed field voltage), thus controlling the motor speed. The PWM signal is generated by the slave microcontroller. This signal will guide the motor driver to vary the voltage supplied to motor to maintain at the required speed. The master microcontroller is programmed with the desired motor number, speed, operating period and direction of the motor from the 44 matrix keypad. Besides, it also lets the user monitor the performance of the system easily across the 420 LCD display. The serial peripheral interfacing (SPI) mode is used for the communication between the master and the two slaves. The master sends the data which include motor number, speed, operating period and it's direction to the slaves by SPI communication technique.

Abstrak Penelitian ini bertujuan untuk merancang pengendali kecepatan motor DC secara remote dengan algoritma DC Chooper atau PWM (Pulse Width Modulation) berbasis mikrokontroler M68HC11. Susunan perangkat keras pengendali kecepatan motor DC pada penelitian ini terdiri atas 5 bagian utama rangkaian, yaitu sistem remote, modul mikrokontroler M68HC11, motor driver, motor DC, dan rotary encoder. Sistem remote terdiri atas pemancar dan penerima. Sisi pemancar digunakan mengatur kecepatan motor secara remote, terdiri dari tiga tombol yang berfungsi untuk menaikan, menurunkan, dan mereset kecepatan. Sistem remote bekerja pada frekuensi 27 MHz dan digunakan untuk mengatur 8 tingkat kecepatan motor DC.

A new switch mode power amplifier (SMPA) topology particularly suitable for energy efficient amplification of radio frequency pulse width modulation (RF-PWM) signals is derived. It is analytically shown that high efficiency can be maintained over a wide power dynamic range if the imaginary part of the Class-E load impedance is varied along with the duty cycle (pulse width). Using the theory developed, an explicit design procedure is presented that allows practical realization of the proposed topology from the circuit and component specifications. Following the design procedure, and using in-house (Chalmers University) SiC varactor diodes to implement the tunable imaginary load impedance, a 2 GHz 10 W peak output power GaN HEMT circuit demonstrator is realized. RF-PWM input signals for characterization of the prototype PA is generated with a dedicated 65 nm CMOS modulator. The measurements show that a drain efficiency > 70% can be obtained over an 6.5 dB dynamic range, which verifies the theory presented and demonstrates the feasibility of the proposed PA topology.

Nowadays, LED has become an emerging technology due to lifetime, luminous ef icacy, power rating, and color property. So it becomes an alternative light source to replace conventional light sources in various lighting and display applications. It finds application in television, laptops, advertising displays, computer displays and optical control purposes. The developments in the LEDs have initiated the scope in designing drivers with ef icient control. The dc-dc converters which are used to generate bi-level current to improve the luminous ef icacy of Light Emitting Diode (LED). Amplitude mode and Pulse Width Modulation (PWM) mode are the two conventional driving techniques used in LED drivers. Amplitude mode driving technique uses constant Direct Current (DC) to drive the LED and provides a higher luminous intensity but lacks in flexibility control. Besides, PWM mode driving technique uses a pulse of dc current having higher level and zero level. It provides more flexible dimming control and color stability, but it has low luminous intensity. The bi-level current driving technique which combines the advantages of the two conventional driving techniques is discussed. A parallel and cascaded buck dc-dc converter is designed to generate the bi-level current for LED. In this paper, Resistive load is used instead of LED. The performances of the converters and tested with the simulation using MATLAB/Simulink

At the end of this project created a module practice driving electricity that purpose to simplify the learning process and the lack of cover module practice existing. Then created a series inverter of 3phase as the supply induction motor 3 phase. Module use this Mikrokontroller ATMega 8535 by using the C language to generate a PWM (Pulse Width Modulation). Signal of PWM generation is used to switching mosfet on the buck converter with frequency 40KHz duty cycle that can be set between 50% -70% and also to switching mosfet inverter 3phase with conduction mode 180 ° and constant frequency switching can be set 50Hz. Observation shows that % error of 26.47% for duty cycle 50% and 11.11% for the duty cyle 70%.

Precise, cheap control and monitoring the speed of DC motor is ever hot area of work. In the present paper we have attempted to implement speed control and feedback monitoring for a 12 Volt/1000 RPM rated motor. Speed control is done with help of PWM pins on Arduino/AVR board and H-bridge IC L293D. Feedback speed monitoring is based on IR pair based interrupt monitoring. Hence Sensing and calculation part of process is handled by Arduino/AVR board. All of this is implemented with help of PC based user interface developed in C#. In a typical user interface speed control is achieved with help of trackBar and speed monitoring with help of Text window, was we get direct readout of current speed in RPM.

In this work software-based PID controller with gain scheduling is implemented to drive a DC motor. LabVIEW PID controller tool with its associated gain scheduling VI was used. Motor start up interval was experimentally analyzed and divided into three regions with three related PID gains sets. Gain scheduling selection criterion was based on the dynamic error absolute value, and it was realized by using case structures. Experiments show that speed overshoot was eliminated and drive system response became faster. Generally it is possible to auto tune the PID controller to achieve a response with the required static or dynamic specifications.

This paper proposes two maximum constant boost control methods for the Z-source inverter, which can obtain maximum voltage gain at any given modulation index without producing any low-frequency ripple that is related to the output frequency. Thus the Z-network requirement will be independent of the output frequency and determined only by the switching frequency. The relationship of voltage gain to modulation index is analyzed in detail and verified by simulation and experiment.

A worldwide system was developed for solar photovoltaic (PV) applications. The demand for "clean" power generation is primarily powered here. The grid-based PV systems would become most important player in prospect mixed power systems, combined with multiple power electronic converters. Strict demands on the entire PV network have been made to achieve consistent & effective power generation from PV systems. Development of power converters in PV systems is being built in response. This paper offers a description of the latest power electronic converters used widely in residential applications, in three-phase PV systems. This paper also discusses demands for three-stage grid-connected PV systems and common systems management strategies.

A new family of zero-current-transition (ZCT) pulsewidth-modulated (PWM) converters is proposed. The new family of converters implements zero-current turn-off for power transistor(s) without increasing voltagdcurrent stresses and operates at a fixed frequency. The proposed converters are deemed most suitable for high-power applications where the minority-carrier semiconductor devices (such as IGBT's, BJT's, and MCT's) are predominantly used as the power switches. Theoretical analysis is verified on a 100 kHz, 1 kW ZCT-PWM boost converter using an IGBT.

In this paper, a new method is proposed for controlling the motors of ICaSbot (IUST Cable Suspended Robot), which is a modiied version of crane aiming to object handling in industrial environments. In order to provide more accurate tracking, torque and speed of the motors are controlled simultaneously, using inverse kinematics and inverse dynamics of the robot. The equations of the motors are evaluated as a look-up table by conducting some special experimental tests and calibrations, while their data sheets and motor parameters are not available. The required feedforward signal of the motors are estimated by the aid of inverse dynamics of the robot, while its errors are compensated by the aid of PID controller on the speed and torque of the motor. As a result, the required (Pulse Width Modulation) PWM of the motor is exerted to produce a desired angular velocity, while a speciic amount of torque is applied on the motors. Not only the voltage of the motors is controlled using the mentioned PWM, but also the current is improved using the feedback control of the torques. PID gains are optimized using Ziegler-Nichols method. By the aid of the mentioned combination of feedforward and feedback controlling terms of the motor speed and torque, the desired trajectory is tracked with the highest possible accuracy. EEciency of the proposed method is eventually proved by comparing the experimental tests with simulation results.

Multilevel inverter is an important alternative technique in high power, medium voltage power control. Multilevel inverter topology is classified in to diode clamped multilevel inverter (DCMLI), flying capacitors multilevel inverter, cascaded inverter with separate dc source. This project presents diode clamped multilevel inverter with sinusoidal pulse width modulation (SPWM) framework. The carrier based SPWM technique is developed to facilitate its implementation in diode clamped multilevel inverter. Diode clamped multilevel inverter using MOSFET as switching device is used in this particular project. Furthermore, in this study reduction of harmonics has been stressed on using diode clamped multilevel inverters. It also states the adverse effects of Total Harmonic Distortion (THD) on generation and transmission equipments. It also explains about Common Mode Voltage and its effects in brief. Multilevel Inverters have been designed, modeled and simulated and the output results have been depicted in the form of waveforms, THD analysis modules using MATLAB SIMULINK and the results are systematically tabulated.

A worldwide system was developed for solar photovoltaic (PV) applications. The demand for "clean" power generation is primarily powered here. The grid-based PV systems would become most important player in prospect mixed power systems, combined with multiple power electronic converters. Strict demands on the entire PV network have been made to achieve consistent & effective power generation from PV systems. Development of power converters in PV systems is being built in response. This paper offers a description of the latest power electronic converters used widely in residential applications, in three-phase PV systems. This paper also discusses demands for three-stage grid-connected PV systems and common systems management strategies.

In biochemistry analyzer the temperature  play crucialrole  as many of the  health  parameters  are tested  at precise  temperature.  In  automated  bio-chemistry  analyzer,  precise  temperature  control  is  achieve
d  by using the peltier device as heat pump and PID control action. The temperature is measured at the flow cell using  the  LM-35  temperature  sensor  and  set  point  temperature  is set  by  using  the  PWM  output  of  a microcontroller employed for the control action. In the presented work, the temperature control is achieved at  an  accuracy  of  ±0.1 0C  by  controlling  the  design  parameters  of  the  heat  pump  circuit.  Further,  besides controlling  the  temperature  at  desired  set  point,  the  temperature  achieving  rate  has  to  made  as  fast  as possible. This is made by using an enhanced current source by suitable designing the peltier driving circuit

Most precise classification of CVD (color vision deficits) can be provided by using anomaloscope. Today anomaloscopes are available, which can evaluate red-green (Rayleigh) and blue-green (Moreland) color defects. Our aim is to create and calibrate commercially available LEDs based anomaloscope for diagnosis of red-green color vision defects. Other field of use of anomaloscope is a seasonal and overall variation of normal color vision in Latvian population.

Pulse Width Modulation (PWM) is a common technique used in many different applications. This technique is the heart of the inverter system. This paper reported a modified strategy in asynchronous unipolar sinusoidal PWM (SPWM) switching scheme based on ACEX1K50TC144-3 Altera Field Programmable Gate Array (FPGA). The carrier frequency was designed for 20 kHz and the fundamental frequency was designed to adjust 1 to 100 Hz, with step increase in 1 Hz. A new SPWM signal generation strategy is proposed and compared to traditional SPWM generation technique. The design entry is conducted by Max+plus II version 10.2 through schematic and VHDL programming. The verification in level simulation and hardware realization has been done. As the result, the proposed modified SPWM signal generation strategy works properly and can reduces the usage of logic cell (LC) until 63.75%. Index Terms-Drive, FPGA, inverter, PWM. Tole Sutikno (M'07 IEEE) received his B.Eng. degree in electrical engineering from Diponegoro Mochammad Facta (M'07 IEEE) received his full bachelor degree in electrical power engineering from University of Hasanuddin, Ujung Pandang, Indonesia, his master degree with cum laude in Electrical Power System from

In this paper, modeling and PWM based control of an electro-pneumatic system, including the four 2-2 valves and a double acting cylinder are studied. Dynamic nonlinear behavior of the system, containing fast switching solenoid valves and a pneumatic cylinder, as well as electrical, magnetic, mechanical, and fluid subsystems are modeled. A DC-DC power converter is employed to improve solenoid valve performance and suppress system delay. Among different position control methods, a proportional integrator derivative (PID) controller and fuzzy logic controller (FLC) are evaluated. An experimental setup, using an AVR microcontroller is implemented. Simulation and experimental results verify the effectiveness of the proposed control strategies.