CHAPTER-1INTRODUCTION1.1 GENERALTo design a high efficiency and high step up converter and implement it for interfacing heavy load with PV source. Now a days renewable energy is increasingly valued and employed worldwide because of energy shortage and environmental contamination. Renewable energy systems generate low voltage output. Thus, high step-up dc/dc converters have been widely employed in many renewable energy applications such fuel cells, wind power generation, and photovoltaic (PV) systems.Depending on the application nature, several types of static power converters are necessary for the adequate conversion and conditioning of the energy provided by primary sources such as photovoltaic arrays, wind turbines, and fuel cells. Besides, considering that the overall cost of renewable energy systems is high, the use of high-efficiency power electronic converters is a must.1.2 LITRATURE SURVEYJ. T. Bialasiewicz, Renewable energy systems with photovoltaic power generators: Operation and modeling IEEE Trans. Ind. Electron., vol. 55, no. 7, pp. 27522758, Jul. 2008. A substantial increase of photovoltaic (PV) power generators installations has taken place in recent years, due to the increasing efficiency of solar cells as well as the improvements of manufacturing technology of solar panels. These generators are both grid-connected and stand-alone applications Systems with PV arrayinverter assemblies, operating in the slave-and-master modes, are discussed.T. Kefalas and A. Kladas, Analysis of transformers working under heavily saturated conditions in grid-connected renewable energy systems IEEE Trans. Ind. Electron., vol. 59, no. 5, pp. 23422350, May 2012. Researchers have proposed transformer less solutions for connecting renewable-energy power plants to the grid. Apart from lack of efficiency and increased cost and weight of the transformer, one of the reasons is the dc input current that causes transformer saturation. The purpose of this paper is the development of a finite-element computational tool that is going to aid transformer manufacturers in designing distribution transformers specifically for the renewable-energy market. It is based on a generalized macroscopic representation of electrical steels used in the transformer manufacturing industry that enables the accurate evaluation of electromagnetic field distribution of transformer cores under heavily saturated conditions.T. Zhou and B. Francois, Energy management and power control of a hybrid active wind generator for distributed power generation and grid integration, IEEE Trans. Ind. Electron., vol. 58, no. 1, pp. 95104, Jan. 2011. Classical wind energy conversion systems are usually passive generators. The generated power does not depend on the grid requirement but entirely on the fluctuant wind condition. A dc-coupled wind/hydrogen/super capacitor hybrid power system is studied in this paper. The purpose of the control system is to coordinate these different sources, particularly their power exchange, in order to make controllable the generated power.
1.3 EXISTING SYSTEMBoost Converter (Step-Up Converter)A boost converter (step-up converter) is a power converter with an output voltage is greater than input voltage. Here coupled inductor boost converter are used because it can be effectively used to reduce the duty ratio and the voltage stress of the switch. A single coupled inductor boost converter cell is treated as a phase and such phases are connected in parallel and operated at the same switching frequency. The main drawback is this converter cannot achieve a high step-up conversion with high efficiency because of the resistances of elements or leakage inductance; also, the voltage stresses are large.
Fig1.1Boost converterFly Back ConverterTheflyback converteris used in bothAC/DCandDC/DCconversion withisolationbetween the input and any outputs. The buck-boost converter works by storing energy in the inductor during the ON phase and releasing it to the output during the OFF phase. With the transformer the energy storage is in the magnetization of the transformer core. The drawback of this converter losses s more because` of the using transformer. Efficiency is very less and the cost and size of the converter is very high.
Fig 1.2 Flyback converter1.4 PROPOSED SYSTEMRenewable energy systems generate low voltage output, and thus, high step-up dc/dc converters have been widely employed in many renewable energy applications such fuel cells, wind power generation, and photovoltaic (PV) systems. Such systems transform energy from renewable sources into electrical energy and convert low voltage into high voltage via a step-up converter, which can convert energy into electricity using a grid-by-grid inverter or dc micro grid. The high step-up conversion may require two-stage converters with cascade structure for enough step-up gain, which decreases the efficiency and increases the cost. Despite these advances, high step-up single-switch converters are unsuitable to operate at heavy load given a large input current ripple, which increases conduction losses. The conventional interleaved boost converter is an excellent candidate for high-power applications and power factor correction. Unfortunately, the step-up gain is limited, and the voltage stresses on semiconductor components are equal to output voltage. Hence, based on the aforementioned considerations, modifying a conventional interleaved boost converter for high step-up and high-power application is a suitable approach.
Fig 1.3 Typical renewable energy system
Fig 1.4 High Step up Interleaved Converter with Voltage Multiplier Module1.5 BLOCK DIAGRAM
Fig.1.5 Block Diagram of high step up interleavedConverter with voltage multiplier module.1.5.1 Block Diagram ExplanationPV PANELIn High step up interleaved converter with multiplier module, we have the PV panel for getting the dc supply from solar energy. The low power can be increased by using the step up converter with voltage multiplier module. The required voltage for optoisolator and PIC microcontroller, Buffer is 12V and 5V respectively.POWER SUPPLY Driver circuits need 12V and 5V. Microcontroller need 5V supply, so we convert 230V AC supply is first step down in to 15V by using step down transformer. Then this 15V AC is converted in to DC by using Full bridge rectifier which has high efficiency than all other methods. This 15V DC is converting into 12V DC and 5v DC by using 7812 and 7805 regulator respectively. The capacitor is used to provide smooth variation in voltage. For indication purpose we used LED with 1K resistor to limit current flow to the LED.
PIC12F508 PIC12F508 belongs to a class of 8-bit microcontrollers of RISC architecture. Its general structure is shown on the following map representing basic blocks. Program memory (FLASH) - for storing a written program.Since memorymade in FLASH technology can be programmed and cleared more than once, it makes this microcontroller suitable for device development.EEPROM - data memory that needs to be saved when there is no supply. It is usually used for storing important data that must not be lost if power supply suddenly stops. For instance, one such data is an assigned temperature in temperature regulators.Application of PIC12F508 perfectly fits many uses, from automotive industries and controlling home appliances to industrial instruments, remote sensors, electrical door locks and safety devices. It is also ideal for smart cards as well as for battery supplied devices because of its low consumption.POWER MOSFET The MOSFET, or Metal-Oxide-Semiconductor, Field-Effect Transistor is by far the most common field effect transistor in both digital and analog circuits. The MOSFET is composed of a channel of n-type or p-type semiconductor material, and is accordingly called an NMOSFET or a PMOSFET. Unfortunately, many semiconductors with better electrical properties than silicon, such as gallium arsenide, do not form good gate oxides and thus are not suitable for MOSFETs.The gate terminal is a layer of polysilicon (polycrystalline silicon) or aluminum placed over the channel, but separated from the channel by a thin layer of insulating silicon dioxide. The state of the art MOSFETs are available with ratings up to 500V, 140A. BUFFERThese buffers/line drivers are designed to improve both the performance and PC board density of TRI-STATE buffers/drivers employed as memory-address Drivers, clock drivers, and bus-oriented transmitters/receivers. Featuring 400 Mv of hysteresis at each low current PNP data line input, they provide improved noise rejection and high fan out outputs and can be used to drive terminated lines down to 133X.1.6 MODES OF OPERATIONThe proposed circuit has four modes of operation namely mode I, mode II, mode III, mode IV, mode V, mode VI mode VII and mode VIII operation.MODE 1During Mode 1, the power switch S1 remains in ON state, and the other power switch S2 begins to turn off. The diodes Dc1, Db1, and Df2 are reversed biased. The energy stored in magnetizing inductor Lm2 transfers to the secondary side of coupled inductors.
Fig.1.7 mode 1 operationMODE 2 During the Mode 2, the current iDc2 has naturally decreased to zero due to the magnetizing current distribution, and hence, diode reverse recovery losses are alleviated and conduction losses are decreased. The power switch S1 remains in ON state, and the other power switch S2 begins to turn off. The diodes Dc1, Db1, and Df2, Dc2 are reversed biased.
Fig.1.8 mode 2 operationMODE 3: During the Mode 3,the power switch S1 remains in ON state, and the other power switch S2 begins to turn on. The diodes Dc1, Dc2, Db1, Db2, and Df2 are reversed biased.. Thus, the magnetizing inductor Lm2 still transfers energy to the secondary side of coupled inductors.
Fig.1.9 mode 3 operationMODE 4During the Mode 4, both of the power switches S1 and S2 remain in ON state, and all diodes are reversed biased. Both currents through leakage inductors Lk1 and Lk2 are increased linearly due to charging by input voltage source Vin.
Fig.1.10 mode 4 operationMODE 5During the Mode 5, the power switch S2 remains in ON state, and the other power switch S1 begins to turn off. The diodes Dc2, Db2, and Df1 are reversed biased. The voltage stress on power switch S1 is clamped by clamp capacitor Cc2 which equals the output voltage of the boost converter.
Fig.1.11 mode 5 operationMODE 6 During the Mode 6, the current iDc1 has naturally decreased to zero due to the magnetizing current distribution, and hence, diode reverse recovery losses are alleviated and conduction losses are decreased. The power switch S2 remains in ON state, and the other power switch S1 begins to turn off. The diodes Dc1, Dc2, Db2, and Df1 are reversed biased.
Fig.1.12 mode 6 operationMODE 7During the Mode 7, the power switch S2 remains in ON state, and the other power switch S1 begins to turn on. The diodes Dc1, Dc2, Db1, Db2, and Df1 are reversed biased. The series leakage inductors Ls quickly release the stored energy to the output terminal via flyback forward diode Df2.Thus, the magnetizing inductor Lm1 still transfers energy to the secondary side of coupled inductors.
Fig.1.13 mode 7 operationMODE 8During the Mode 8, both of the power switches S1 and S2 remain in ON state, and all diodes are reversed biased. Both currents through leakage inductors Lk1 and Lk2 are increased linearly due to charging by input voltage source Vin.
Fig.1.14 mode 8 operation
CHAPTER-2COMPONENTS DESCRIPTION2.1 SOLAR POWERSolar power is the conversion of into electricity, either directly using photovoltaic (PV), or indirectly using concentrated solar power (CSP). Concentrated solar power systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. Photovoltaics convert light into electric current using the photoelectric effect. Solar power is the conversion of sunlight into electricity. Sunlight can be converted directly into electricity using photovoltaics (PV), or indirectly with concentrated solar power (CSP), which normally focuses the sun's energy to boil water which is then used to provide power.
Fig.2.1 Solar Power2.2 PHOTOVOLTAIC POWER SYSTEMSSolar cells produce direct current (DC) power which fluctuates with the sunlight's intensity. For practical use this usually requires conversion to certain desired voltages or alternating current (AC), through the use of inverters. Multiple solar cells are connected inside modules. Modules are wired together to form arrays, then tied to an inverter, which produces power at the desired voltage, and for AC, the desired frequency/phase. Many residential systems are connected to the grid wherever available, especially in developed countries with large markets. In these grid-connected PV systems, use of energy storage is optional. In certain applications such as satellites, lighthouses, or in developing countries, batteries or additional power generators are often added as back-ups. Such stand-alone power systems permit operations at night and at other times of limited sunlight.
Fig.2.3 Photovoltaic Power Systems2.3 INTERLEAVED BOOST CONVERTER A switching converter is an electronic power system which transforms an input voltage level into another for a given load by switching action of semiconductor devices. A high power efficient dc-dc converter is strongly desired and has found widespread applications. Examples include aerospace, sea and undersea vehicles, electric vehicles (EV),Hybrid Electric Vehicle (HEV), portable electronic devices like pagers, and microprocessor voltage regulation [1].In dual-voltagepowersystems, the dc-to-dc converter is required to step-up voltage provided from the low-voltagebusorback uppartforthe existinghigh-power devicesin the application that use this power system. A power system consisting of fuel cell, battery and possibly other energy storage components used in electric vehicles and stationarypowersystemapplications,which normallyrequireahigh-power boost converter forenergy management that employs an energy storage component to assist the slow-responding fuel cell. Multiphase converter with interleaved control is essential for the high-power boost converter in order to reduce the ripple current and to reduce the size of passive component. So far few literatures related to the controllerdesign of the high-power interleaved boost converter can be found.There have been many papers describing the use ofmultiphase buck converters, especially forhigh-performance high-power applications [1,9,10]. However, all the advantages of interleaving, such as higher efficiency and reduced input and output ripple for voltage/current, are also realized in the boost topology. Most of the controllers used in buck applications apply equallywell when configured foruse in an interleaved boost application. In [1] multi-phasebuck converter controlled byPID is presented. This paper following the same approach used in buckconverters and applied it on boost converter, PID is configured using ZieglerNichols tuning method, where the individual effects of P, I, and D is tuned on the closed-loop response to give the required characteristics.
Fig interleaved boost converterRenewable energy is derived from natural resources that are replenished constantly. The commonly used renewable energy systems include photovoltaic cells and fuel cells. A suitable DC-DC converter is proposed for highly efficient renewable energy systems. Interleaved Boost Converter (TBC) topology is discussed in this paper for renewable energy applications. The advantages of interleaved boost converter compared to the classical boost converter are low input current ripple, high efficiency, and faster transient response, reduced electromagnetic emission and improved reliability. Three cases of interleaved boost converter have been considered and analyzedA novel high step-up converter, which is suitable for renewable energy system, is proposed in this paper. Through a voltage multiplier module composed of switched capacitors and coupled inductors, a conventional interleaved boost converter obtains high step-up gain without operating at extreme duty ratio. The configuration of the proposed converter not only reduces the current stress but also constrains the input current ripple, which decreases the conduction losses and lengthens the lifetime of the input source. In addition, due to the lossless passive clamp performance, leakage energy is recycled to the output terminal. Hence, large voltage spikes across the main switches are alleviated, and the efficiency is improved. Even the low voltage stress makes the low-voltage-rated MOSFETs be adopted for reductions of conduction losses and cost. Finally, the prototype circuit with 40-V input voltage, 380-V output, and 1000-W output power is operated to verify its performance. The highest efficiency is 97.1%2.4 R LOADA resistive load is one which generates heat with the application of voltage. The amount of heat generated per unit time is equal to the voltage times the current flowing through the load. A resistive load, in reference to electricity, converts current into other forms of energy, such as heat; for example, an electric heater or an incandescent bulb, and there is no risk of blowback.A resistive load converts some of the energy of the current flow into heat (Watts). There is a direct proportional relationship between the current flowing (Amps), the voltage across the resistor (Volts) and the value of the resistor itself (Ohms). The relationship stands regardless of whether alternating current or direct current is used.Resistive loads are typically used to convert current into forms of energy such as heat. Unlike inductive loads, resistive loads generate no magnetic fields. Common examples include most electrical heaters, and traditional incandescent lighting loads. In a resistive load, the current is in phase with the voltage the current rises immediately to its steady-state value, without first rising to a higher value. Resistive loads can therefore be said to have little inrush current. Since resistive loads are designed to optimally convert current into energy at specific voltages, resistive loads can benefit fromvoltage optimization, in order to conserve power and extend the life of electronics.Voltage optimization provides resistive loads such as light bulbs and large-scale heaters with the optimal operating voltage, and ensures a consistent supply of quality power in order to prevent the effects of potentially harmful brownouts (a drop in the voltage coming from theelectrical power supply)and power surges (spikes from a power supply, also known as over voltages) that can damage increasingly sensitive equipment. Less complex conventional resistive loads such as light bulbs can also have their consumption reduced and their operating life extended by the optimal, stable power supplied by voltage optimization.2.5 LIGHT EMITTING DIODE (LED) LOADA light emitting diode (LED) is known to be one of the bestoptoelectronic devicesout of the lot. The device is capable of emitting a fairly narrow bandwidth of visible or invisible light when its internal diode junction attains a forward electric current or voltage. The visible lights that an LED emits are usually orange, red, yellow, or green. The invisible light includes the infrared light. The biggest advantage of this device is its high power to light conversion efficiency. Fig symbol of LED
That is, the efficiency is almost 50 times greater than a simple tungsten lamp. The response time of the LED is also known to be very fast in the range of 0.1 microseconds when compared with 100 milliseconds for a tungsten lamp. Due to these advantages, the device wide applications as visual indicators and asdancing light displays. We know that a P-N junction can connect the absorbed light energy into its proportional electric current. The same process is reversed here. That is, the P-N junction emits light when energy is applied on it. This phenomenon is generally called electro luminance, which can be defined as the emission of light from a semi-conductor under the influence of an electric field. The charge carriers recombine in a forward P-N junction as the electrons cross from the N-region and recombine with the holes existing in the P-region. Free electrons are in the conduction band of energy levels, while holes are in the valence energy band. Thus the energy level of the holes will be lesser than the energy levels of the electrons. Some part of the energy must be dissipated inorder to recombine the electrons and the holes. This energy is emitted in the form of heat and light.The electrons dissipate energy in the form of heat for silicon and germanium diodes. But in Galium- Arsenide-phosphorous (GaAsP) and Galium-phosphorous (GaP) semiconductors, the electrons dissipate energy by emitting photons. If the semiconductor is translucent, the junction becomes the source of light as it is emitted, thus becoming a light emitting diode (LED). But when the junction is reverse biased no light will be produced by the LED, and, on the contrary the device may also get damaged.
CHAPTER-3HARDWARE DESCRIPTION3.1 MICROCONTROLLER (PIC12F508)PIC12F508 belongs to a class of 8-bit microcontrollers of RISC architecture. Its general structure is shown on the following map representing basic blocks. Program memory (FLASH)- for storing a written program.Since memory made in FLASH technology can be programmed and cleared more than once, it makes this microcontroller suitable for device development.EEPROM - data memory that needs to be saved when there is no supply. It is usually used for storing important data that must not be lost if power supply suddenly stops. For instance, one such data is an assigned temperature in temperature regulators. If during a loss of power supply this data was lost, we would have to make the adjustment once again upon return of supply.Thus our device looses on self-reliance.RAM - data memory used by a program during its execution. In RAM are stored all inter-results or temporary data during run-time. PORTA and PORTB are physical connections between the microcontroller and the outside world. Port A has five, and port B has eight pins.FREE-RUN TIMER is an 8-bit register inside a microcontroller that works independently of the program. On every fourth clock of the oscillator it increments its value until it reaches the maximum (255), and then it starts counting over again from zero. As we know the exact timing between each two increments of the timer contents, timer can be used for measuring time which is very useful with some devices.CENTRAL PROCESSING UNIT has a role of connective element between other blocks in the microcontroller. It coordinates the work of other blocks and executes the user program. 3.2 PIN diagram
ApplicationsPIC12F508 perfectly fits many uses, from automotive industries and controlling home appliances to industrial instruments, remote sensors, electrical door locks and safety devices. It is also ideal for smart cards as well as for battery supplied devices because of its low consumption.3.3 MOSFET
Fig.2.2 Mosfet SymbolThe metaloxidesemiconductor field-effect transistor (MOSFET, MOS-FET, or MOS FET) is a transistor used for amplifying or switching electronic signals. Although the MOSFET is a four-terminal device with source (S), gate (G), drain (D), and body (B) terminals, the body (or substrate) of the MOSFET often is connected to the source terminal, making it a three-terminal device like other field-effect transistors. Because these two terminals are normally connected to each other (short-circuited) internally, only three terminals appear in electrical diagrams. In enhancement mode MOSFETs, a voltage drop across the oxide induces a conducting channel between the source and drain contacts via the field effect. The term "enhancement mode" refers to the increase of conductivity with increase in oxide field that adds carriers to the channel, also referred to as the inversion layer. The channel can contain electrons (called an nMOSFET or nMOS), or holes (called a pMOSFET or pMOS), opposite in type to the substrate.3.4 ISOLATION CIRCUITIsolation circuits are specially designed circuits to isolate the POWER CIRCUIT and CONTROLLER CIRCUIT. These circuits are used to provide ground. ICs are usually used to provide this isolation. OPTO-ISOLATORIn electronics, an opto-isolator, also called an optocoupler, photocoupler, or optical isolator, is a component that transfers electrical signals between two isolated circuits by using light. Opto-isolators prevent high voltages from affecting the system receiving the signal. Commercially available opto-isolators withstand input-to-output voltages up to 10kV and voltage transients with speeds up to 10kV/s. A common type of opto-isolator consistes of an LED and a phototransistor in the same package. Opto-isolators are usually used for transmission of digital (on/off) signals, but some techniques allow use with analog (proportional) signals.
Fig.2.3.1Schematic diagram of an opto-isolator OPTO ISOLATOR TLP250:The TOSHIBA TLP250 consists of a GaAlAs light emitting diode and a integrated photo detector.This unit is 8lead DIP package.TLP250 is suitable for gate driving circuit of IGBT or power MOS FET. Input threshold current: IF=5mA(max.) Supply current (ICC): 11mA(max.) Supply voltage (VCC): 1035V Output current (IO): 1.5A (max.) Switching time (tpLH/tpHL): 1.5s(max.) Isolation voltage: 2500Vrms(min.) UL recognized: UL1577, file No.E67349Pin Configuration (top view)
1. N.C.2. Anode3. Cathode4. N.C.5. GND6. VO (Output)7. VO8. VCCOperationAn opto-isolator contains a source (emitter) of light, almost always a near infraredlight-emitting diode (LED), that converts electrical input signal into light, a closed optical channel (also called dielectrical channel), and a photo sensor, which detects incoming light and either generates electric energy directly, or modulateselectric current flowing from an external power supply. The sensor can be a photo resistor, a photodiode, a phototransistor, a silicon-controlled rectifier(SCR) or a triac. Because LEDs can sense light in addition to emitting it, construction of symmetrical, bidirectional opto-isolators is possible. An optocoupled solid state relay contains a photodiode opto-isolator which drives a power switch, usually a complementary pair of MOSFETs. A slotted optical switch contains a source of light and a sensor, but its optical channel is open, allowing modulation of light by external objects obstructing the path of light or reflecting light into the sensor. Applications:i. AC mains detectionii. Reed relay drivingiii. Switch mode power supply feedbackiv. Telephone ring detectionv. Logic ground isolationvi. Logic coupling with high frequency noise rejection
3.5 BUFFER:These buffers/line drivers are designed to improve both the performance and PC board density of TRI-STATE buffers/drivers employed as memory-address Drivers, clock drivers, and bus-oriented transmitters/receivers. Featuring 400 Mv of hysteresis at each low current PNP data line input, they provide improved noise rejection and high fan out outputs and can be used to drive terminated lines down to 133X.3.6 VOLTAGE REGULATORA voltage regulator is designed to automatically maintain a constant voltage level. A voltage regulator may be a simple "feed-forward" design or may include negative feedbackcontrol loops. It may use an electromechanical mechanism, or electronic components. Depending on the design, it may be used to regulate one or more AC or DC voltages.
Fig.2.5 Voltage RegulatorElectronic voltage regulators are found in devices such as computer power supplies where they stabilize the DC voltages used by the processor and other elements. In automobile alternators and central power station generator plants, voltage regulators control the output of the plant. In an electric power distribution system, voltage regulators may be installed at a substation or along distribution lines so that all customers receive steady voltage independent of how much power is drawn from the line.IC78XXThe 78xx (sometimes L78xx, LM78xx, MC78xx...) is a family of self-contained fixed linear voltage regulatorintegrated circuits. The 78xx family is commonly used in electronic circuits requiring a regulated power supply due to their ease-of-use and low cost. For ICs within the family, the xx is replaced with two digits, indicating the output voltage (for example, the 7805 has a 5volt output, while the 7812 produces 12volts). The 78xx line are positive voltage regulators: they produce a voltage that is positive relative to a common ground
Fig.2.5.1 IC 78XX78xx ICs have three terminals and are commonly found in the TO220 form factor, although smaller surface-mount and larger TO3 packages are available. These devices support an input voltage anywhere from a couple of volts over the intended output voltage, up to a maximum of 35 to 40volts depending on the make, and typically provide 1 or 1.5 amperes of current (though smaller or larger packages may have a lower or higher current rating).
CHAPTER 4SIMULATIONDETAILS4.1 INTRODUCTIONNow a days Simulation has become a very powerful tool in industrial application as well as in academics, It is now essential for an electrical engineer to understand the concept of simulation and learn its use in various applications. Simulation is one of the best ways to study the system or circuit behavior without damaging it. Many industries are spending a considerable amount of time and money in doing simulation before manufacturing their product. In most of the research and development (R&D) work, the simulation plays very important role. Without simulation, it is quite impossible to proceed further. It should be noted that in power electronics, computer simulation and a proof of concept hardware prototype in the laboratory are complimentary to each other. 4.2 MATLAB TOOLMATLAB is a high-performance language for technical computing. It integrates computation, visualization, and programming in an easy-to-use environment where problems and solutions are expressed in familiar mathematical notation. Typical uses include Math and computation Algorithm development Data acquisition Modeling, simulation, and prototyping Data analysis, exploration, and visualization Scientific and engineering graphics Application development, including graphical user interface buildingMATLAB is an interactive system whose basic data element is an array that does not require dimensioning. This allows you to solve many technical computing problems, especially those with matrix and vector formulations, in a fraction of the time it would take to write a program in a scalar non interactive language such as C or Fortran. The name MATLAB stands for matrix laboratory. MATLAB was originally written to provide easy access to matrix software developed by the LINPACK and EISPACK projects. Today, MATLAB engines incorporate the LAPACK and BLAS libraries, embedding the state of the art in software for matrix computationSim Power Systems:SimPower Systems and other products of the Physical Modeling product family work together with Simulink to model electrical, mechanical, and control systems. SimPower Systems operates in the Simulink environment. Therefore, before starting this user's guide, you should be familiar with Simulink. For help with Simulink, see the Simulink documentation or, if you apply Simulink to signal processing and communications tasks (as opposed to control system design tasks), see the Signal Processing Block set documentation.The Role of Simulation in Design:Electrical power systems are combinations of electrical circuits and electromechanical devices like motors and generators. Engineers working in this discipline are constantly improving the performance of the systems. Requirements for drastically increased efficiency have forced power system designers to use power electronic devices and sophisticated control system concepts that tax traditional analysis tools and techniques. Further complicating the analyst's role is the fact that the system is often so nonlinear that the only way to understand it is through simulation .Land-based power generation from hydroelectric, steam, or other devices is not the only use of power systems. A common attribute of these systems is their use of power electronics and control systems to achieve their performanceobjectives.SimPower Systems is a modern design tool that allows scientists and engineers to rapidly and easily build models that simulate power systems. SimPower Systems uses the Simulink environment, allowing you to build a model using simple click and drag procedures. Not only can you draw the circuit topology rapidly, but your analysis of the circuit can include its interactions with mechanical, thermal, control, and other disciplines.SimPower Systems LibrariesThe libraries contain models of typical power equipment such as transformers, lines, machines, and power electronics. These models are proven ones coming from textbooks, and their validity is based on the experience of the Power Systems Testing and Simulation Laboratory of Hydro-Qubec, a large North American utility located in Canada, and also on the experience of Evolve de Technologies superior and Universities Laval. The SimPower Systems main library, power lib, organizes its blocks into libraries according to their behavior. The powerlib library window displays the block library icons and names. Double-click a library icon to open the library and access the blocks. The main SimPower Systems powerlib library window also contains the Powergui block that opens a graphical user interface for the steady-state analysis of electrical circuit Interfacing the Electrical Circuit with Simulink:The Voltage Measurement block acts as an interface between the SimPower Systems blocks and the Simulink blocks. For the system shown above, you implemented such an interface from the electrical system to the Simulink system. The Voltage Measurement block converts the measured voltages into Simulink signals Similarly , the Current Measurement block from the Measurements library of powerlib can be used to convert any measured current into a Simulink signal. You can also interface from Simulink blocks to the electrical system.
Measuring Voltages and Currents:When you measure a current using a Current Measurement block, the positive direction of current is indicated on the block icon (positive current flowing from + terminal to terminal). Similarly, when you measure a voltage using a Voltage Measurement block, the measured voltage is the voltage of the + terminal with respect to the terminal. However, when voltages and currents of blocks from the Elements library are measured using the Multimeter block, the voltage and current polarities are not immediately obvious because blocks might have been rotated and there are no signs indicating polarities on the block icons Basic Principles of Connecting Capacitors and Inductors .4.3 MERITS OF COMPUTER AIDED SIMULATION
Benefits of computer-aided analysis in power electronics circuits are enormous. They are listed as follows:1. Evaluating the effects of variations in elements, such as resistors, power semiconductor devices, transformers, and so on.2. The assessment of performance, improvements or degradations.3. Evaluating the effects of noise and signals distortion without the need of expensive measuring instruments
4.4 DEMERITS OF COMPUTER AIDED SIMULATIONWe need to realize that are several factors that make simulation of power electronics systems very challenging. Solid-state power semiconductor switches including diodes and thyristors present extreme nonlinearly during their transition from one state to the other. The simulation program ought to be able to represent this switching of states in an appropriate manner. The simulation may take a long time. The time constants, or in other words the response time of various parts within the system, may differ by several orders of magnitude. Accurate models are not always available. This is especially true for power semiconductor devices but is also the case for magnetic components, such as inductors and transformers.4.5 SIMULATION RESULT
4.5.1 Conventional Circuit Diagram:
Fig.4.1 shows conventional circuit diagram
4.5.2 Input Voltage Waveform:
Fig4.2 shows the simulated input voltage for the Conventional circuit in MATLAB.4.5.3 Triggering Pulses:
The fig .4.3shows the triggering pulses for the simulation of Conventional Circuit.4.5.4 Output Voltage and Current Waveforms:
The fig4.4 shows the simulated output voltage and current for conventional circuit in MATLAB.
4.2.5 PROPOSED CIRCUIT DIAGRAM:
Fig4.5 shows that the proposed circuit diagram4.5.7 INPUT VOLTAGE:
The simulated input voltage for the proposed circuit is shown in figure.4.74.5.8 TRIGGERING PULSE:
The simulated triggering pulse for the proposed circuit is shown in figure.4.84.5.9 VOLTAGE ACROSS SWITCHES (S1,S2):
This figure 4.9shows voltage across switches (S1, S2) for the proposed circuit4.5.10 VOLTAGE ACROSS DIODE (VDb1, VDb2):This figure .4.10 shows that the voltage across diode (VDb1,VDb2) for the proposed circuit.4.5.11 VOLTAGE ACROSS DIODE (VDc1, VDc2)
This fig.4.11shows that the voltage across diode (VDc1,VDc2) for the proposed circuit.4.5.12 OUTPUT VOLTAGE:The simulated output voltage for the proposed circuit is shown in figure4124.5.13 OUTPUT CURRENT:
The simulated output current for the proposed circuit is shown in figure.4.134.5.14 OUTPUT POWER:The simulated output power for the proposed circuit is shown in figure.4.5.144.6 HARDWARE COMPONENTS DESIGN:Proposed Method:Inductance : L = (1-D) * L = (1-0.25) * 0.01e-3 = 7.5e-6 ~ 1e-6 HResistance: V R =I 380 = 0.93 = 408.6 ~ 415 Output Power: P = Vo*Io = 380*0.93 = 353.4WEfficiency:
Vo ~ Vin E = *100 Po 340 = *100 353.4 = 96.2%Voltage stress: RVoltage stress = Vo
415 = 380 = 1.09
Conventional Method:
Voltage stress: RVoltage stress = Vo
150 = 25
= 6
CHAPTER 5HARDWARE IMPLEMENTATION
CIRCUIT DIAGRAM:
Fig.5.1. Overall circuit diagram
Fig 5.2 Hardware kit5.4 ADVANTAGE High step up gain(40v 380v with 1000w). High efficiency. Low conduction losses. Reduces current stress on switches.
5.4 APPLICATIONS Photovoltaic (pv) system. DC drives. Fuel cells.
6. CONCLUSIONThis paper has presented the theoretical analysis of steady state, related consideration, simulation results, and experimental results for the proposed converter. The proposed converter has successfully implemented an efficient high step-up conversion through the voltage multiplier module. The interleaved structure reduces the input current ripple and distributes the current through each component. In addition, the lossless passive clamp function recycles the leakage energy and constrains a large voltage spike across the power switch. Meanwhile, the voltage stress on the power switch is restricted and much lowerthan the output voltage.
FUTURE EXPANTION:
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