Design and simulation of three-level inverter

Number of pages: 150 File Format: word File Code: 32271
Year: 2014 University Degree: Master's degree Category: Electrical Engineering
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    Dissertation for receiving the master's degree "M.Sc" in power electrical engineering

    Abstract

    Inverters can produce single-phase and three-phase ac voltages from a constant or variable dc voltage. There are various methods to control the output voltage of the inverter, which is introduced in this thesis from an inverter system with solar panel input. In this system, the voltage obtained from the solar panel is first converted into a set voltage by a boost converter. Then, this DC voltage is converted into an alternating voltage using a three-level inverter with SVM control. The three-level inverter reduces the switching frequency and reduces the losses. To check the correctness of the operation, the system is simulated in the simulink environment of Matlab software.

    Chapter One: Introduction

    Introduction                   

    Direct to alternating current converters are known as inverters. The task of an inverter is to convert a direct input voltage into an alternating and symmetrical output voltage current with the desired amplitude and frequency. The output voltage can have a fixed or variable value at a fixed or variable frequency. The output voltage can be obtained by changing the direct input voltage and keeping the inverter gain constant. On the other hand, if the direct input voltage is constant and cannot be controlled, a variable output voltage can be obtained by changing the gain of the inverter. This action is usually done by controlling the width modulation (pwm) inside. The efficiency of the inverter can be defined as the ratio of the output alternating voltage to the direct input voltage.

    The waveform of the output voltage in the inverter should be sinusoidal in ideal inverters, however, in scientific inverters these waveforms are non-sinusoidal and have a series of harmonics. In medium power and low power applications, square or almost square voltages may be acceptable, but in high power applications, sine waves with very low distortion are needed. By having fast power semiconductor parts, it is possible to significantly reduce output voltage harmonics by using switching methods. [14] [

    Inverter applications in industry:

    Inverters are widely used in industry (such as AC motor drives with variable speed, induction heating, auxiliary power supplies and sources Uninterruptible power supply) The input of the inverter may be a battery, coal cell, solar cell or any other direct source. The output of single-phase inverters is usually equal to (1) 120 volts at a frequency of 60 Hz, (2) 220 volts at a frequency of 50 Hz, and (3) 115 volts at a frequency of 400 Hz.

    In high power three-phase systems, the output The usual ones are 220/380 V at 50 Hz frequency, (2) 120/208 V at 60 Hz frequency and (3) 115/200 V at 400 Hz frequency).]11 [

    Categories of inverters in terms of function:

    Inverters can be divided into two general categories. divided into: 1) single-phase inverters and 2) three-phase inverters

    Each category can use controlled switching on and off elements (such as BJTs, MOSFETs, IGBTs, MCTs, SITs, and GTOs) or thyristors with forced commutation, depending on the type of application. These inverters usually use PWM control signals to generate the output voltage. If the input voltage of the inverter is constant, the inverter is called a voltage-fed inverter, and if the input current is kept constant, it is called a voltage-fed inverter, and if the input current is kept constant, it is called a current-fed inverter, and if the input is controllable, it is called a variable dc connection inverter.  ]11[

    Abstract

    Inverters can be a constant or variable dc voltage, single phase and three-phase ac voltage to control the output voltage of the various Nmaynd.rvsh Aynvrtrvjvd that the Payanamh of a solar panel inverter input voltage is introduced.These first results Solar panel by a boost converter, the voltage is set using an inverter converts the DC voltage Grdd.sps this three level by controlling the voltage conversion Shvd.astfadh Azaynvrtr three-level SVM reduces switching frequency to reduce losses. To verify performance, system software matlab simulink environment is simulated.

  • Contents & References of Design and simulation of three-level inverter

    List:

    Chapter One: Introduction. 2

    1-1-Introduction. 2

    1-1-1-Inverter applications in industry: . 3

    1-2- Classification of inverters in terms of function: 3

    1-2-1- working principles of inverter circuits:. 4

    1-3-Inverter features. 8

    The second chapter: A review of the past. 12

    2-1-types of inverters. 12

    2-1-1-voltage inverters. 13

    2-1-2 single-phase inverter. 15

    2-1-3-three-phase inverter. 27

    2-1-4-Inverter in terms of the number of levels:. 36

    2-1-5-types of multi-level inverter: 38

    2-1-6 advantages and disadvantages of multi-level inverter. 39

    2-1-6-1-advantages. 40

    2-1-6-2 disadvantages: 40

    2-2-advanced designs: 40

    Chapter three: modeling. 43

    3-1-Vector space modeling types. 43

    3-1-1-sinusoidal pulse width modulation (spwm) 43

    3-1-2-hysteresis modulation. 44

    3-1-3-Executing SVM calculations using vector classification technique. 45

    3-3-Study of main circuits of three-level converters. 50

    3-3-1-circuit topology and working principle of three-level converters:. 50

    3-3-2-Mathematical modeling of the three-level converter:. 51

    3-3-3-three-level vectors:. 53

    3-4-SVM theory:. 54

    3-5- Vector analysis of three-phase inverter: . 57

    3-6-NPC three-level inverter:. 62

    Chapter Four: Solar System. 67

    4-1-Solar cell analysis and performance. 67

    4-1-1- Introduction of solar energy and how to produce it. 67

    4-2-History of using solar energy. 68

    4-3-Advantages and disadvantages of solar energy. 69

    4-4-History of solar cells. 71

    4-5-Reasons for the need for a solar cell. 71

    4-6-types of solar cells. 72

    4-6-1-single crystal cells. 72

    4-6-2-. Polycrystalline cells. 72

    4-6-3-amorphous silicon. 72

    How does 7-4-silicon make a solar cell? 73

    4-7-1-Making solar cells. 75

    4-7-2-advanced solar cells. 75

    4-8-Description of a cell. 76

    4-9-photovoltaic systems. 78

    4-9-1-Introducing the photovoltaic phenomenon. 78

    4-9-2- Introduction of photovoltaic systems and the advantages and disadvantages of these systems. 79

    4-9-2-1-Advantages of electricity generation using photovoltaic systems. 79

    4-9-2-2-disadvantages of photovoltaic systems. 80

    4-9-3-Use of photovoltaic systems. 80

    4-9-4-familiarity with different parts of a complete photovoltaic system. 81

    4-9-5-Efficiency of solar cells. 82

    4-9-6 The effect of the increase in ambient temperature on the electrical characteristic parameters of the solar cell 82

    4-9-7-The effect of changing the amount of energy absorbed from the sun in the electrical characteristic curve of the solar cell 83

    4-9-8-Increasing the efficiency of photovoltaic cells. 83

    4-10-components of photovoltaic systems. 85

    4-10-1-Solar panel or module. 85

    4-10-2-Regulator. 86

    4-10-3 Energy storage units in photovoltaic systems. 86

    4-10-4- output voltage regulator. 87

    4-10-5-voltage inverter. 88

    4-11-Classification of photovoltaic systems in terms of how to supply consumer load 88

    Chapter five: Simulation. 91

    5-1- Comparison of multi-level inverters with each other. 91

    5-2- Simulation of different types of inverters and removing harmonics. 93

    5-2-1-Simulated circuit of a single-phase inverter and presentation of results. 93

    5-2-2-simulated circuit of a three-phase full-bridge inverter. 95

    5-2-3-Inverter output voltage. 96

    5-2-4- Simulation of two-level inverter. 98

    5-2-5-3-level inverter simulation. 100

    5-2-6-filtering the output voltage and removing harmonics of the output voltage. 101

    5-3-Simulation of multi-level inverters and minimizing the amount of THD in it. 104

    5-3-1-Inverter structure. 104

    5-3-2-Elements and components used in simulation. 104

    5-3-3-simulated seven-level inverter circuit. 105

    5-3-4-Output voltage of seven-level inverter and THD rate per modulation index m=0.7 106

    5-3-5-Inverter output voltage and THD rate per modulation index m=0.8. 108

    5-3-6-Inverter output voltage and THD rate per modulation index m=0.84. 109

    5-3-7-Inverter output voltage and THD amount to109

    5-3-7-Inverter output voltage and THD rate per modulation index m=0.9. 110

    5-3-8-Comparison of the amount of THD resulting from simulation for four different modulation indices 111

    5-3-9-How to calculate keying angles in MATLAB. 112

    5-3-10-other cases. 112

    5-4-design and simulation of a filter sample for photovoltaic system. 114

    Conclusion: 130

    Source:

                           

    Bakhshaei A., Sasih Radhar R., Saidifar M., Rahimi A. 2019. "Control of three-phase multilevel voltage source inverters using spatial vector modulation and with the help of vector classification method". independence Year 23. Number 1. pp. 15-32.

    Khosh Nazari H. 2016. "Using photovoltaic system to supply electricity to television stations". The sixth national energy conference. 22 and 23 Khordad 1386

    Rosouli Kohimi M, Zafaranchizadeh MT, Kanaan P. 1388 "Economic evaluation of solar photovoltaic power plant construction in Iran". The twenty-fourth international electricity conference. Tehran. Aban 88 2017. "A serious method of controlling multi-level inverters using fuzzy spatial vector modulation". 19th Iran Electrical Engineering Conference. Tarbiat Modares University. 1387.

    Manshipour S, Khalafi F. 2017. "Necessity of localization of solar electricity (photovoltaic) technology in the country". The first national renewable energy conference, Islamic Azad University, Takestan branch. 16 August 87

    Mousavi SZ, Amiri P, Cheshfar M, Sadoughi J. 2012. "Design of three-level inverter with hysteresis control of flow mode based on fuel cell". 2nd hydrogen and fuel cell conference, pp. 1-8

    Yusfi S., Parsa Moghadam M., Dashti R. 2016, "Evaluating the impact of distributed generation systems on the performance of electricity distribution networks with a case study of photovoltaic generators". The sixth national energy conference.

Design and simulation of three-level inverter