Đồ án điện công nghiệp DESIGNING PWM INVERTER USING IGBT FOR DRIVING INDUCTION MOTOR

Đồ án điện công nghiệp tiếng anh Thiết kế biến tần ba pha sử dụng inverterThiết kế và mô phỏng mạch inverter 3 pha sử dụng phần mềm PSIM 9.1Điều khiển động cơ không đồng bộ sử dụng linh kiện điện tử công suất IGBT

MINISTRY OF EDUCATION AND TRAINING CAN THO UNIVERSITY COLLEGE OF ENGINEERING TECHNOLOGY INDUSTRIAL ELECTRICAL PROJECT DESIGNING PWM INVERTER USING IGBT FOR DRIVING INDUCTION MOTOR SUPERVISOR STUDENT October 2021 CAN THO UNIVERSITY COLLEGE OF ENGINEERING TECHNOLOGY DEPARTMENT OF ELECTRICAL ENGINEERING SOCIALIST REPUBLIC OF VIETNAM Independence – Freedom - Happiness Can The, October 4, 2021 INDUSTRIAL ELECTRICAL PROJECT OUTLINE SEMESTER 1, ACADEMIC YEAR 2021/2021 Project name: Designing PWM Inverter Using IGBT For Controlling Induction Motor Student full name: Supervisor full name: Purpose: • Studying about IGBT, PWM techniques and speed control of induction motor • Designing and simulating a PWM circuit for induction motor control Location and project duration: Location: Department of Electrical Engineering, College of Engineering Technology, Can Thoi University Project duration: 15 weeks Introduction to the situation related to the project: Nowadays, induction motors are one of the most common electrical devices in the world, ranging from household applications to large industrial machines Compare to DC motor, induction motor is cheaper and simpler in design and operation However, induction motor speed cannot the control easily so that in situation where the speed of the motor is frequently changed, the DC motor is more favorable In order to utilizing the beneficial characteristics of the induction motor, the inverter is used to change the electrical frequency feeding to the motor, which changing the motor speed Main ideas and limitation of the project: Chapter 1: Introduction on Inverter and IGBT 1.1 Introduction on Inverter 1.1.1 Definition 1.1.2 Output voltage control of Inverter 1.1.3 Multiple pulse-width modulation 1.1.4 Sinusoidal pulse-width modulation 1.2 Introduction on IGBT 1.2.1 Definition 1.2.2 Performance parameters Chapter 2: Induction Motor Speed Control Theory 2.1 Introduction 2.2 Structure of Induction Motors 2.3 Fundamentals of Induction Motors 2.4 Power in an Induction Motor 2.5 Speed Control of Induction Motor Chapter 3: System Design 3.1 Introduction 3.2 Motor Parameter 3.3 Rectifier Circuit 3.4 DC-DC Converter 3.5 Control Circuit Chapter 4: Simulation and Result Analysis 4.1 Simulation 4.1.1 Introduction on PSim 4.1.2 Drawing Power Circuit 4.1.3 Drawing Control Circuit 4.2 Result Analysis 4.2.1 DC Input Voltage 4.2.2 Operating at 1500 rpm 4.2.3 Operating at 2000 rpm 4.2.4 Operating at 1000 rpm Chapter 5: Conclusion 5.1 Conclusion 5.2 Future Work Methods of implementation: documents and books skimming, researching on the Internet for information and design Project planning: - Week 6th to week 9th: Information gathering Week 10th to week 14th: Designing and Simulating Week 15th: Reporting STUDENT SUPERVISOR Acknowledgment ACKNOWLEDGMENT I would like to extend our deepest gratitude to my adviser, for his valuable comments and patience Without his support I would never been able to achieve this milestone He has not only given positive feedback but also supported and motivated me for work I hope that this project will serve as a valuable foundation for my graduation thesis I am thankful to Dr h who made me able and gave me the idea to this project I would also like to thank to my friends and acquaintances who supported and motivated and stood beside me throughout my project Student: Le Nguyen Anh Tuan i Preface PREFACE In many industrial processes, commercial equipment and appliances, most of the motor drives have been designed to operate at basically constant speed or with very little speed control The main reason is the reliable and economical induction motors operating on the available constant frequency ac power supply For many mechanical systems, it is well informed that a variable speed drive provides improved performance and energy efficiency Traditionally, DC motor drives are used for those systems However, DC motor drive is too expensive for all but special applications for which the compromise of constant speed was not acceptable Nowadays, with the help of low-cost power-electronic switching devices and microprocessor-based control, new varying speed drives designed to work with induction motor are used more in new systems Student: Le Nguyen Anh Tuan ii Table of Content TABLE OF CONTENT ACKNOWLEDGMENT i PREFACE ii TABLE OF CONTENT iii FIGURE INDEX -v TABLE INDEX vi CHAPTER 1: INTRODUCTION ON INVERTER AND IGBT 1.1 Introduction on Inverter -1 1.1.1 Definition 1.1.2 Output voltage control of Inverter 1.1.3 Multiple pulse-width modulation -1 1.1.4 Sinusoidal pulse-width modulation 1.2 Introduction on IGBT -3 1.2.1 Definition 1.2.2 Performance parameters -4 CHAPTER 2: INDUCTION MOTOR SPEED CONTROL THEORY -5 2.1 Introduction -5 2.2 Structure of Induction Motor -5 2.3 Fundamentals of Induction Motors 2.4 Power in an Induction Motor -7 2.5 Speed Control of Induction Motor -8 CHAPTER: SYSTEM DESIGN -9 3.1 Introduction -9 3.2 Motor Parameter -9 3.3 Rectifier Circuit 3.3 Inverter Circuit - 11 3.4 DC-DC Converter 11 3.5 Control circuit 12 CHAPTER 4: 13 SIMULATION AND RESULT ANALYSIS 13 Student: Le Nguyen Anh Tuan iii Table of Content 4.1 Simulation 13 4.1.1 Introduction on Psim - 13 4.1.2 Drawing Power Circuit 13 4.1.3 Drawing Control Circuit - 14 4.2 Result Analysis - 16 4.2.1 DC Input Voltage - 16 4.2.2 Operating at 1500 rpm - 17 4.2.3 Operating at 2000 rpm - 18 4.2.4 Operating at 1000 rpm - 18 CHAPTER 5: 19 CONCLUSION - 19 5.1 Conclusion 19 5.2 Future Work 19 REFERENCES - 20 Student: Le Nguyen Anh Tuan iv Figure Index FIGURE INDEX Figure 1.1 Multiple Pulse-Width Modulation (MPWM) (1) Figure 1.2 Sinusoidal Pulse-Width Modulation (SPWM) (1) Figure 1.3 SPWM for Three-phase Inverter (1) .3 Figure 1.4 Cross section and equivalent circuit of IGBT Figure 2.1 Structure of an Induction Motor (3) .5 Figure 2.2 Squirrel-cage Rotor (4) Figure Power-flow Diagram in An Induction Motor (4) Figure 3.1 Induction Motor Drive Block Diagram Figure 3.2 Three-phase Bridge Rectifier .10 Figure 3.3 Output Voltage Waveforms and Conduction Time of a Diode 10 Figure 3.4 Three-phase Inverter Circuit 11 Figure 3.5 Boost Converter 12 Figure 3.6 V/F Control Diagram 12 Figure 4.1 PSim Simulation Environment .13 Figure 4.2 Power Circuit 13 Figure 4.3 Rectifier Subcircuit .14 Figure 4.4 DC-DC Converter Subcircuit .14 Figure 4.5 Inverter Subcircuit 14 Figure 4.6 Control Circuit 14 Figure 4.7 Polar-to-Cartesian Transformation Waveforms 16 Figure 4.8 Three-phase Reference Signal 16 Figure 4.9 G1 and G2 Waveforms 16 Figure 4.10 Rectified Voltage Waveform 17 Figure 4.11 Converted Voltage Waveform 17 Figure 4.12 Speed, Line Voltage and Currents Profile at 1500 rpm .17 Figure 4.13 Line voltage and currents at steady-state operation 18 Figure 4.14 Line voltage and currents profile at 2000 rpm 18 Figure 4.15 Line voltage and currents profile at 1000 rpm 18 Student: Le Nguyen Anh Tuan v Table Index TABLE INDEX Table 4.1 Elements of The Control Circuit 14 Student: Le Nguyen Anh Tuan vi Chapter 2: Induction Motor Speed Control Theory placing skewed conductors, which may be copper, aluminum or alloy bar These rotor bars are shorted at both ends through end rings as shown in Figure 2.2.[6] Figure 2.2 Squirrel-cage Rotor [6] 2.3 Fundamentals of Induction Motors When a three-phase AC voltage source is applied to the stator windings, which are displaced in space with respect to each other by 120 electrical degrees A rotating magnetic field in the air gap will be produced by the three-phase currents following in the stator windings The speed of this rotating magnetic field is called synchronous speed, 𝑛𝑠𝑦𝑛𝑐 , which is defined by 𝑛𝑠𝑦𝑛𝑐 = 120𝑓 𝑝 (𝑟𝑒𝑣𝑜𝑙𝑢𝑡𝑖𝑜𝑛 𝑝𝑒𝑟 𝑚𝑖𝑛𝑢𝑡𝑒 𝑜𝑟 𝑟𝑝𝑚 ) (2.1) where 𝑝 is a number of poles and 𝑓 is the frequency of the current The rotating magnetic field in the air gap induces voltage in the rotor circuit, as well as the stator circuit The induced voltage in the stator circuit is defined as 𝐸𝑠 = 4.44𝑁𝑠 𝜙𝐾𝜔𝑠 𝑓 (2.2) where 𝑁𝑟 is the number of turn per phase, 𝐾𝜔𝑠 is call the winding factor and 𝜙 is the air gap flux per pole The induced voltage in the rotor also produces a rotor current in the shorted rotor windings The rotor will start rotating as the torque in the rotor winding is developed by the interaction between this rotor current and the stator rotating magnetic field The rotor steady-state speed 𝑛 (rpm) is always less than the synchronous speed 𝑛𝑠𝑦𝑛𝑐 The difference between the synchronous speed and the rotor speed is called the slip speed, which is expressed as a fraction of the synchronous speed and can be defined as Slip: 𝑠 = 𝑛𝑠𝑦𝑛𝑐 −𝑛𝑚𝑒𝑐ℎ 𝑛𝑠𝑦𝑛𝑐 (2.3) The slip is a very significant factor in the induction motor as most of its performance characteristics of an induction motor such as the developed torque, current, efficiency and power factor The operating slip depends on the load An Student: Le Nguyen Anh Tuan Chapter 2: Induction Motor Speed Control Theory increase in the load will cause the rotor to slow down, increase the load A decrease in the load will cause the rotor to speed up and decrease the slip Normally, the operating slip range from to 5% [7] The frequency 𝑓𝑟 in the rotor circuit at the slip 𝑠 is called the slip frequency and is defined as 𝑓𝑟 = 𝑠 × 𝑓 (2.4) The rotor speed and the induced voltage in the rotor circuit at the slip 𝑠 is defined as 𝐸𝑟 = 4.44𝑁𝑟 𝜙𝐾𝜔𝑟 𝑓 × 𝑠 𝑛𝑚𝑒𝑐ℎ = 120𝑓 𝑝 × (1 − 𝑠) (2.5) (2.6) 2.4 Power in an Induction Motor In an induction motor, the input power 𝑃𝑖𝑛 is not equal to the output power (𝑃𝑜𝑢𝑡 ) due to many losses As shown in Figure 2.3, part of the input power is lost because of the stator copper loss (𝑃𝑠 ) and iron loss (𝑃𝑓 ) The remaining power is transferred to the rotor magnetically through the air gap between the stator and the rotor It is called the air-gap power (𝑃𝑎𝑔 ) which is also the input power of the rotor circuit Part of it is lost due to the copper loss in the rotor (𝑃𝑟 ) The remaining power is converted to mechanical form Part of this is lost because of mechanical losses such as windage and friction losses (𝑃𝑣 ) Stray-load loss consisted of all losses that are not mentioned above The rest is the mechanical output power (𝑃𝑜𝑢𝑡 ), which is the useful power output from the machine The rating of the motor is specified in term of value of the mechanical output power.[6] 𝑃𝑖𝑛 = 3𝑉𝑠 𝐼𝑠 𝑐𝑜𝑠𝜑 (2.7) 𝑃𝑜𝑢𝑡 = 𝑃𝑖𝑛 −𝑃𝑠 − 𝑃𝑓 − 𝑃𝑟 − 𝑃𝑣 (2.8) Figure Power-flow Diagram in An Induction Motor [6] The efficiency of the induction motor is 𝜂= Student: Le Nguyen Anh Tuan 𝑃𝑜𝑢𝑡 𝑃𝑖𝑛 (2.9) Chapter 2: Induction Motor Speed Control Theory 2.5 Speed Control of Induction Motor An induction motor operates at a constant speed when connected to a constant voltage and frequency power source such as the power grid However, in many industrial applications require several speeds or a continuously adjustable range of speeds Because of their low cost and ruggedness, the induction motors are also being use for variable speed drives in many applications The speed control of an induction motor could be classified into two methods, slip control and synchronous speed control By changing the slip, the slip of an induction motor can be varied at a constant stator frequency The slip can be changed by varying the stator voltage or the rotor resistance However, since the efficiency of induction motors depend on the operating slip, the speed control by this method will lead to efficiency reduction and its also have restricted speed control range The rotor of an induction motor follows the stator magnetic field which rotates at the synchronous speed As can be seen from equation (2.1) and (2.6), changing the stator frequency is more fundamental to the speed control Although the synchronous speed can be changed by changing the number of poles, this require elaborate windings construction and the speed can be changed only in discrete steps Thus, it is more effective and economical to change the frequency Equation (2.2) shown that by changing the supply frequency, 𝐸𝑠 will change to maintain the same air gap flux The terminal voltage is equal to 𝐸𝑠 if the stator voltage drop is neglected In order to avoid saturation and to minimize losses, motor is operated at rated air gap flux by varying terminal voltage with frequency so as maintain v/f ratio constant at rated value When the supply frequency is smaller than the rated value, the v/f ratio can be maintained at rate value, the output torque of the machine also remains unchanged However, when the supply frequency is higher than the rated value, the voltage cannot be increased higher than its rated value, so the v/f ratio is reduced The same also happened for the output torque and it is said that the motor is working in flux-weakening region [1, 7] Student: Le Nguyen Anh Tuan Chapter 3: System Design CHAPTER: SYSTEM DESIGN 3.1 Introduction A diagram for the induction motor drive is shown in Figure 3.1 There are four main parts in the system First, the three-phase AC source will be converted into a unidirectional signal using a rectifier Then, the rectified signal will be boosted to obtain a desired DC voltage Finally, the inverter uses IGBT to convert the DC signal into three-phase signals with desired frequency and voltage level to be fed to the motor The control circuit creates gating signals to control the firing sequence of the IGBTs in the inverter Figure 3.1 Induction Motor Drive Block Diagram 3.2 Motor Parameter The motor parameter used in the system is listed below: - Rated output power: Rated voltage: Rated current: Number of poles: Rated frequency: Rated speed: Efficiency: Power factor: 10 hp (7.5 kW) 380 V (line to line) 15.6 A poles 50 Hz 1430 rpm 87.4% 86.2% 3.3 Rectifier Circuit Because of a three-phase power supply power system, a three-phase full-wave bridge rectifier is used and it is presented in Figure 3.2 It can operate with or without the use of a transformer and gives six-pulse ripples on the output voltage The diodes are numbered in order of conduction sequences, namely D1 - D2, D3 - D2, D3 - D4, Student: Le Nguyen Anh Tuan Chapter 3: System Design D5 - D4, D5 - D6, and D1 - D6 When a resistive load is connected to the output, the waveforms and conduction times of diodes are shown in Figure 3.3 Figure 3.2 Three-phase Bridge Rectifier Figure 3.3 Output Voltage Waveforms and Conduction Time of a Diode The average output voltage 𝑉𝑜(𝑎𝑣𝑔) can be calculated as 𝑉𝑜(𝑎𝑣𝑔) = 3√3 𝜋 𝑉𝑚 = 1.654𝑉𝑚 (3.1) where 𝑉𝑚 is the peak phase supply voltage The rms output voltage is 𝑉𝑜(𝑟𝑚𝑠) = ( + 9√3 1/2 ) 4𝜋 (3.2) × 𝑉𝑚 = 1.6554𝑉𝑚 The ripple factor of the output waveform is defined as 𝑅𝐹 = √( 𝑉𝑜(𝑟𝑚𝑠) 𝑉𝑜(𝑎𝑣𝑔) )2 − (3.3) Ripple factor is a measure of the effectiveness of a rectifier circuit The smaller the ripple factor, the better the output signals will be compared to the ideal DC When a purely resistive load is connected to the output, the ripple factor is only 4.2% However, in practice, the load is commonly consisted of inductive and resistive components As a result, the ripple factor is much higher than that of purely resistive load If the ripple exceeds the specified value, different unwanted effects appear in the system such as stray heating, audible noise, etc Ripple can be mitigated using a capacitor connected in parallel with the output A capacitor with a value of 820 𝜇𝐹 is chosen for a ripple factor of 0.92% The output voltage of the rectifier circuit is 530.1V.[8] 10 Student: Le Nguyen Anh Tuan Chapter 3: System Design 3.3 Inverter Circuit The DC signal from the rectifier circuit need to be changed back into desired AC signal and feed to the motor Inverter Circuit presented in Figure 3.4 is used to full fill that task The three-phase inverter circuit consists of six IGBTs with diodes integrated Three IGBTs remain on at any instant time Figure 3.4 Three-phase Inverter Circuit The PWM technique is used to control the gate signals of each IGBT The rms output voltage can be varied by varying the modulation index M, defined by 𝐴 𝑀= 𝑟 (3.4) 𝐴𝑐 where 𝐴𝑟 is the amplitude of the carrier wave and 𝐴𝑐 is the amplitude of the reference signal For M = 0.8 and the amplitude of the AC output (𝑉𝑙𝑟𝑚𝑠 ) = 380 𝑉, the DC input voltage is calculated by 𝑉𝑑𝑐 = 𝑉𝑙𝑟𝑚𝑠 𝑀 × √3 (3.5) The result DC input voltage is 550 V, which is higher than the output voltage of the rectifier circuit A DC-DC converter is required to step-up the DC voltage from the rectifier 3.4 DC-DC Converter As discussed above, a step-up (boost) converter is designed to raise the DC voltage form 𝑉𝑖 = 530.1 𝑉 to 𝑉𝑜 = 550 𝑉 and to operate at an average current 𝐼𝑜 = 20 𝐴 The boost converter is shown in Figure 3.5 A square-wave generator is used to create a switching signal for the IGBT at a switching frequency of 25000 Hz The duty cycle of the switching signal is 0.0362, which is calculated by 𝑉 𝑑 =1− 𝑖 (3.5) 𝑉𝑜 To minimize the ripple of the output current and voltage, an inductor with the inductance of 𝐿 = 50 𝑚𝐻 and a capacitor with the capacitance of 𝐶 = 820 𝜇𝐹 are chosen.[8] 11 Student: Le Nguyen Anh Tuan Chapter 3: System Design Figure 3.5 Boost Converter 3.5 Control circuit In this project, the volts/hertz (V/F) control is used to control the speed of the induction motor The V/F control is the most common speed control methods, by varying the voltage and frequency to keep their ratio constant, then the torque produced by induction motor will remain constant In addition, V/F control is the simplest controller because it does not require speed feedback As a result, this controller doesn’t achieve a good accuracy in both speed and torque However, in many industrial applications that does not require precise output speed and torque, the open loop V/F control that does not need feedback is widely used because of their benefits such as: low cost and simplicity A block diagram of the open loop V/F controller for the project is shown in Figure 3.6.[1, 9, 10] Figure 3.6 V/F Control Diagram In the diagram, the desired speed is used to calculate the frequency by using equation (2.1) The angular frequency can be calculated by multiplying the frequency by 2𝜋 and the voltage can be found by using a Look-up Table When the desired frequency is higher than the rated frequency of the motor, the voltage remains at its rated value If the voltage is increase to maintain constant V/F ratio, the insulation of the motor may fail and damage the motor A three-phase reference signal is created after having the desired voltage and frequency Lastly, the reference signal is compared with a triangular carrier signal to create the gating signal that control the IGBTs in the inverter 12 Student: Le Nguyen Anh Tuan Chapter 4: Simulation and Result Analysis CHAPTER 4: SIMULATION AND RESULT ANALYSIS 4.1 Simulation 4.1.1 Introduction on Psim PSIM is a powerful simulation software capable of designing and analyzing power electronics circuit With fast simulation, friendly user interface and waveform processing, PSim provides a powerful simulation environment used for industry research and product development and used for teaching by educational institutions The Psim simulation package consists of three programs: circuit schematic editor SIMCAD, PSIM simulator and SIMVIEW waveform processing program Figure 4.1 illustrates the Psim simulation environment Figure 4.1 PSim Simulation Environment 4.1.2 Drawing Power Circuit As discussed in the previous chapter, the power circuit consists of main subcircuits, namely: rectifier circuit, DC-DC converter circuit, and an inverter circuit Figure 4.2 shows the power circuit The rectifier, converter and inverter subcircuits are illustrated in Figure 4.3, 4.4, 4.5 respectively Figure 4.2 Power Circuit 13 Student: Le Nguyen Anh Tuan Chapter 4: Simulation and Result Analysis Figure 4.3 Rectifier Subcircuit Figure 4.4 DC-DC Converter Subcircuit Figure 4.5 Inverter Subcircuit 4.1.3 Drawing Control Circuit The control circuit for the power circuit is shown in Figure 4.6 The function of elements used in the circuit is shown in Table 4.1 Figure 4.6 Control Circuit Table 4.1 Elements of The Control Circuit 14 Student: Le Nguyen Anh Tuan Chapter 4: Simulation and Result Analysis Block Name Symbol Function The output can be calculated as Math function the mathematical function of the inputs The output is found by using the input based on a preset array of data Lookup table The output is a multiplication of Multiplier the inputs Polar-to-Cartesian transformation Transforming the polar into the Cartesian coordinate r: the amplitude a: angle 𝛼𝛽-to-abc transformation Transforming the 𝛼𝛽 coordinate into the abc coordinate Comparing two input signals The output is when the non-inverting input is higher than the inverting input and vice versa Comparator The output is the inversion of NOT gate On-off controller the input logic signal switch Interfacing between the control circuit and the power circuit Triangular-wave Generating triangular-wave generator with preset parameters The working principle of the control circuit is described as follows First, the desired frequency is calculated using the input speed Next, the angular frequency is calculated by multiplying the frequency by 2𝜋 and is feed into the Polar-to-Cartesian transformation block By using the lookup table, the desired voltage is calculated to keep the V/F ratio constants For comparing with the carrier signal, the output voltage is divided by the rated motor voltage of 380 and multiplied by the modulation index of 0.8 by using a math function block The output signal is also feed to the Polar-toCartesian transformation block As shown in Figure 4.7, the output of the Polar-toCartesian transformation block is two sine waveforms with 90 degrees phase shift 15 Student: Le Nguyen Anh Tuan Chapter 4: Simulation and Result Analysis Figure 4.7 Polar-to-Cartesian Transformation Waveforms The two sine signals are feed into the 𝛼𝛽-to-abc transformation block and the output signal is the three-phase reference signal, which is illustrated in Figure 4.8 Figure 4.8 Three-phase Reference Signal The three-phase reference signal is compared with a triangular carrier signal with frequency of 5kHz and amplitude of 1, resulting in the generation of gating signals for the IGBTs in the inverter subcircuit Figure 4.9 shows the gating signal G1 and G2, which is used to turn on and off IGBT1 and IGBT2, respectively IGBT1 and IGBT2 are in the same branch which cannot be conduct simultaneously As a result, G1 and G2 are inverting of each other Similarly, gating signals G3, G4 and G5, G6 have the same waveform with 120 degrees phase shift Figure 4.9 G1 and G2 Waveforms 4.2 Result Analysis 4.2.1 DC Input Voltage The output voltage of the rectifier subcircuit waveform is shown in Figure 4.10 The waveform has an average value of 536.9V with a small ripple factor of 0.1125% The rectified signal is fed to the DC-DC converter subcircuit to boost the 16 Student: Le Nguyen Anh Tuan Chapter 4: Simulation and Result Analysis voltage to the theoretical value The waveform of the converted voltage is presented in Figure 4.11 After reaching steady-state operation, the average value of the voltage is 590V, which is higher than that of the theoretical value It also has a small ripple factor of 0.1% Figure 4.10 Rectified Voltage Waveform Figure 4.11 Converted Voltage Waveform The DC voltage is fed into the inverter circuit, which is controlled by the control circuit depending on the input speed 4.2.2 Operating at 1500 rpm The desired speed is set to the rated synchronous speed of 1500 rpm The line voltage and current profiles are shown in Figure 4.12 When the motor is starting, the starting current is higher than that of the steady-state At steady-state operation, the line voltage and current waveforms are illustrated in Figure 4.13 The rms value of the line voltage and current is 392 V and 12.6 A, respectively Figure 4.12 Speed, Line Voltage and Currents Profile at 1500 rpm 17 Student: Le Nguyen Anh Tuan Chapter 4: Simulation and Result Analysis Figure 4.13 Line voltage and currents at steady-state operation 4.2.3 Operating at 2000 rpm In this simulation, the reference speed is increased from 1500 rpm to 2000 rpm The line voltage and current profile is shown in Figure 4.14 The rms value of the line voltage remains unchanged at 392 V, but the rms value of the current decreases to 9.5 A Therefore, the output of the motor is also decreased while operating at high speed Figure 4.14 Line voltage and currents profile at 2000 rpm 4.2.4 Operating at 1000 rpm In this simulation, the reference speed is decreased from 1500 rpm to 1000 rpm The line voltage and current profiles are shown in Figure 4.14 The rms value of the line voltage decreases to 300 V and the rms value of the current is 12.6 A Figure 4.15 Line voltage and currents profile at 1000 rpm 18 Student: Le Nguyen Anh Tuan Chapter 5: Conclusion CHAPTER 5: CONCLUSION 5.1 Conclusion The project demonstrates the performance and effectiveness of the PWM Inverter to drive the induction motor The open-loop control circuit provides an easy and simple solution for many industrial applications that not require precise control The project also provided useful information and knowledge about the working principle of the IGBT, inverter and induction motor 5.2 Future Work Due to the impact of the Covid-19 pandemic, many different tests and experiments could not be done in practical situation Future work will include revisiting the circuit design, making a working prototype and improving the controller This project will serve as a valuable foundation for future projects and graduation thesis 19 Student: Le Nguyen Anh Tuan REFERENCES 10 Muhammad, R., Power Electronics Devices, Circuits and Applications 2014, Pearson, Nobel Yaynevi, Tỹrkỗe ỗeviri S Abedinpour, K.S., Chapter - Insulated Gate Bipolar Transistor, in Power Electronics Handbook (Second Edition), M.H Rashid, Editor 2007 J Chapman, S., Electric machinery fundamentals 2004: McGraw-hill Sen, P.C., Principles of electric machines and power electronics 2007: John Wiley & Sons Academia, E Three Phase Induction Motor Construction Available from: https://electricalacademia.com/induction-motor/three-phase-induction-motorconstruction/ Kim, S.-H., Electric motor control: DC, AC, and BLDC motors 2017: Elsevier Petruzella, F.D., Electric Motors and Control Systems 2019: McGraw-Hill Education Pyakuryal, S and M Matin, Filter design for AC to DC converter International Refereed Journal of Engineering and Science, 2013 2(6): p 4249 Patel, J.R and S Vyas, Simulation and Analysis of Constant V/F Induction Motor Drive International Journal of Engineering and Technical Research (IJETR), 2014 2(4): p 151-156 Rani, S., S.N Syed, and S.K Tummala Gate driver circuit design, PWM signal generation using FEZ Panda III and Arduino for inverter in E3S Web of Conferences 2019 EDP Sciences 20 Student: Le Nguyen Anh Tuan ... name: Designing PWM Inverter Using IGBT For Controlling Induction Motor Student full name: Supervisor full name: Purpose: • Studying about IGBT, PWM techniques and speed control of induction motor. .. Introduction on IGBT 1.2.1 Definition 1.2.2 Performance parameters Chapter 2: Induction Motor Speed Control Theory 2.1 Introduction 2.2 Structure of Induction Motors 2.3 Fundamentals of Induction Motors... electromagnetic induction 2.2 Structure of Induction Motor The structure of an induction motor is shown in Figure 2.1 There are many parts in an induction motor, the stator and motor being the