IGBT-ĐỒ-ÁN-ĐIỆN-TỬ-CÔNG-SUẤT-nghịch lưu áp 1 pha

TRƯỜNG ĐẠI HỌC ĐIỆN LỰC KHOA KỸ THUẬT ĐIỀU KHIỂN & TỰ ĐỘNG HÓA Báo cáo Đồ án Điện tử công suất Tên đề tài: Thiết kế nghịch lưu áp pha Giảng viên hướng dẫn: Nguyễn Thị Điệp Sinh viên thực : Phạm Trung Tuấn Anh Lớp: CLC D12 CNTD HÀ NỘI, 10/ 2020 TABLE OF CONTENTS Page Chapter :Introduction 1.1 Inverters and applications 1.1.1:Define 1.1.2 Classify: 1.1.3 Application: 1.1.2 IGBT 1.2.1 Principle 1.2.2 Calculate schematic parameters CHAPTER 2: DESIGN CIRCUIT 2.1 Power circuit valve: 11 2.2 Calculation of choosing IGBT 11 2.3 IGBT protection 2.4 Cooling calculation for IGBT 13 14 2.5 Amplified control signals for IGBTs 15 CHAPTER3: DESIGN THE CONTROL CIRCUIT 3.1 Structure of inverter control circuit 17 3.2 -phase inverter control circuit: 17 3.3 Synchronous 18 3.4 Stitch creating serrated 19 3.5 The comparison stage 20 3.6 Stitch amplification creates pulses 21 CHAPTER 4: Complete circuit simulation 23 OPENING Nowadays, with the rapid development of high-capacity half-sell technology, power converters using power semiconductor components have been widely used in industry and life to meet daily needs the higher the society In practical use of electricity, we need to change the frequency of the supply, inverters are widely used in electric drive, in induction heating devices, in lighting equipment … The inverters are inverters that convert direct to AC indirectly with great practical applications such as aircraft, ship, train drive systems During the period of study and research, is studying and researching the Power Electronics subject and its applications in the fields of modern production systems So in order to master the theory and apply that knowledge in practice, we received the subject project with the topic: "Designing single-phase reverse-voltage circuits" With the assigned topic, we have applied our knowledge to learn and research the theory, especially we delve deeply into design calculations for product completion Under the enthusiastic guidance of teacher Nguyen Thi Diep together with the efforts of the team members, we have completed our project However, due to the limited time and knowledge, the shortcomings are inevitable when implementing this project So I hope to receive many comments from teachers and friends to the topic is more complete Chapter 1: Introduction 1.1 Inverters and applications: 3.6.1 Define: Independent inverter is a device that changes or converts direct current (DC) to alternating current (AC) with fixed or variable frequency 3.6.2 Classify: - Voltage power independent inverter: allow to change from direct voltage (E) to alternating voltage with characteristic as same as grid voltage - Current independent inverter: convert DC to AC - Resonance independent inverter: when active it always forming an RLC resonant oscillating loop - The load of the independent reciprocating is the AC device can be 1-phase or 3phase so it can also be manufactured in two forms: 1-phase inverter 3-phase inverter 1.1.3 Application: - Power supply - Adjusting AC motor speed - Electricity delivery - Metallurgical and energy source converters I.1.2 IGBT A Structure: Regarding the semiconductor structure, IGBT is nearly identical to the MOSFET, the difference is that it has an extra layer connected to the Collector to create a pnp semiconductor structure between the Emiter (similar to the original pole) and the Collector (similar to the drain), without is nn as in mosfet Thus, IGBT can be considered as equivalent to a p-n-p transistor with base current controlled by a MOSFET B, Sign C, Working Principle - Polarize for IGBT star UCE> 0, then on pole G a control voltage Uge> with a large enough value Then, forming a channel with electromagnetic particles like MOSFET, the electrons move towards the pole C, pass the P-N junction to create Colector current - The switching time of the IGBT is faster than conventional transistors, about 0.15ms late when open, about 1ms late when locking Very small IGBT control power usually open as a control voltage of + -15V To open normally + 15V signal, lock signal -15V D, Valve opening conditions - Due to the n-p-n structure, the forward voltage between C and E in IGBT current mode is much lower than Mosfet However, due to this structure, the switching time of the IGBT is slower than that of Mosfet, especially when locked The figure shows the equivalent structure of IGBT with Mosfet and a Tranzitor p-n-p Notation line through IGBT consists of two components: i1 line through Mosfet, i2 stream through Tranzitor The Mosfet part in IGBT can be locked quickly if the charge between G and E is fully discharged, so the current i1 = 0, but i2 will not decline rapidly due to the amount of electrical accumulation in (equivalent to the base of the structure pnp structure) can only be lost due to the self-neutralization of the charge This appears the area of the current lasting when the IGBT is locked - Diagram of testing an IGBT course: -Open process: The IGBT opening process is similar to this one in Mosfet when the input voltage increases from to the value Ug During the delay time when Io is turned on, the control signal charges the capacitor Cgc, causing the voltage between the control terminal and emite to increase exponentially from to the Uge (3 to 5v) value Only from there did Mosfet unfold in the IGBT structure The current between the colecto-emite increases according to the linear rule from to the load current Io during time Tr During Tr time, the voltage between the control terminal and the emite increases to the value Uge determines the value of current Io through the colecto Because diode is still conducting the load current of Io, the voltage Uce is still pinned up to the 1-way voltage Udc Next, the opening process takes place in phases T1 and T2 During these two phases, the voltage between the control terminal remains the same Uge to maintain the current Io, because the control current is purely the discharge current Cgc capacitor IGBT still work in linear mode In the first stage, the lock and recovery process of the diode takes place Due to the regenerative current of the diode Do create a current pulse above the IGBT line of the IGBT The Uce voltage starts to decrease IGBT switches the working point across the linear mode region to the saturation region Stage continues the process of decreasing resistance in the resistive region of the colecto leading to the colecto-emite resistance to the Ron value when fully saturated Uce = IoRon After the opening time Ton when the capacitor Cgc has completed discharge, the voltage between the control pole and the emito continues to increase exponentially with the time constant CgcRg to the final value Ug -Clock process E, Basic parameters of IGBT valve Table 1.IGBT’s parameters No Parameter Voltage Current Control Amplification Power Active mode Parameters’s name Disruptive voltage CE Disruptive voltage GE Maximum voltage between CE terminals Symbol Maximum drain current IC Maximum pulse drain current ICM Maximum GE voltage Voltage GE threshold Conductivity UGE Resistor DS when led Maximum heat generation capacity Loss of energy when opening Loss of energy when locking Open delay time RCE(on) Lock delay time tD(OFF) Drain terminal current increase time Drain terminal current decrease time Input port capacitance tR Measurement mode U(BR)CE U(BR)GẺ UCE UGE(th) gFS PC When short circuit GS When there is resistance to connect between terminal G and E At the specified temperature of the shell With specified pulse width When short circuit CE When UCE>0 According to the regulation With specified shell temperature EON EOFF tD(ON) According to the regulation tF CISS CISS= CGE+ CGC Temparature Output port capacitance Capacitance switch Total charge of the Gate terminal The thermistor set in the middle of the transient "np-shell" Transition-setting thermistor "npenvironment" Thermistor establishes "shell-heatsink" COSS COSS= CGC+ CCE CRSS CRSS= CGC QG According to the regulation With standard heat sink The transient thermistor between transients "npshell" Maximum permissible temperature resistance at "pn" transients ZThj.C With current pulses have specified time TJ(max) Both negative and positive temperatures RThj.C RThj.A No heat sink RThj.S -Analysis of independent single-phase voltage source inverter diagram, bridge diagram: 1) Load’s power: (1.1 2) 11 CHAPTER 2: DESIGN CIRCUIT 2.1 Power circuit valve: Figure 2.1 Power circuit 2.2 Calculation of choosing IGBT - Voltage applied to the valve: U = 310V - Considering the load as resistive, we have the current through the valve I P 500   2.3A U 220 Consider that the selected power valve must be based on current and voltage parameters in the circuit Specifically, when calculating the capacity valves, they must meet the conditions specified by the manufacturer In which the parameters usually must be the first priority when calculating the selection and the capacity is the working voltage of the valve Uv; effective current flows through the valve and the average current flowing through the valve In which the selected valve voltage shall satisfy the condition =(1.6ữ2) => 2ì310 = 620V The flow rate of the flow valve is selected depending on the cooling condition If the public semiconductor and is only cooled by natural convection radiator, the ability to withstand electrical brittle is only 25 ÷ 30% of the rated current written on the valve If 12 the power semiconductor valve is cooled by a radiator and has a cooling fan, the current capacity is 50 ÷ 70% of the rated current written on the valve If the industrial semiconductor valve is cooled by a radiator and has a cooling solution, the current resistance can reach 100% of the rated current on the valve save naturally So we have: I = (25÷30%) IVRMS IVRMS =(2.3*100)/25=9,2A  Select valve yes : = 600V = 10A Based on the above calculation we can choose IGBT : FGA25N120AN Features of FGA25N120AN: - Fast switching speed - Low saturation voltage: VCE (sat) = 2.5 V, IC = 25A - High input impedance 2.3: IGBT FGA25N120AN Symbo l VCES VGES IC ICM Description Lock voltage collectoremitter 1200 Uni t V Voltage gate-emitter ± 20 V 25 A 75 A 125 W One-way colltter current (TC=100oC) Current collectter peak repeat PD Maximum power dissipation (TC=100oC) TJ Transition temperature Symbo l VGE(th) FGA25N120AN Description Threshold voltage o -55 đến +150 FGA25N120 AN gate-emitter 13 Unit 5.5 C Sym bol V VCE(sat) td(on) td(off) tr Saturated collector- VCC= 600 V, Ic= emitter voltage 25A, Delay opening time RG= 10Ω , VGE= Late closing time 15V, Growth time 2.5 V 60 ns 170 ns 60 ns TC = 25°C Table 2.1: Some parameters of FGA25N120A 2.3 IGBT protection -Usually IGBTs are used in high frequency switching circuits, from to tens of kHz At such high switching frequencies, malfunctions can destroy the element very quickly and lead to total equipment failure The most common fault is overcurrent due to short circuit from the load side or from faulty elements due to fabrication or assembly The IGBT current can be disconnected by bringing the control voltage to a negative value However, overcurrent can take the IGBT out of saturation mode, leading to a sudden increase in heat generation capacity, destroying the element after a few switching cycles On the other hand, when locking the IGBT again for a very short time when a very large current leads to too great a current rate, causing overvoltage on the collector, emiter, immediately puncturing the element Besides, there were also unexpected incidents and interference effects Therefore, we must calculate the protection for the semiconductor valves when the failure occurs For short circuit protection and overload current use Aptomat or fuse - Principle of choosing this device is according to the current with Ibv = (1,11,3)Ilv -The protective current of Aptomat must not exceed the short circuit current of the transformer From above, we choose the fuse to protect with: Ibv = (1,11,3)Ilv= 1.3*2.3=2.99 (A) We choose fuse 3A to protect over current for the IGBT 2.4 Cooling calculation for IGBT 14 Semiconductors are very sensitive to temperature If working, the temperature of the laminate surface is higher than the permissible temperature Tjm ,it can damage the semiconductor device So the calculation of radiant heat for the joint is very necessary: + When calculating the diagram of thermal isotherms shown as follows: Inside: Tj:is the temperature of the joint Tv: The temperature of the case of the semiconductor device Tr: The temperature of the radiator fins Ta: The air temperature of the working environment Rjv: Thermal resistance between the coupling face and the semiconductor housing Rvt: The heat resistance between the cover and the diffuser Rra: Heat resistor fins and ambient air Figure 2.4: Diagram of thermal isotherms + The temperature is transferred from the hot to the cold zone, the heat capacity transferred is proportional to the wrong heat and inversely proportional to the thermistor Rth ∆P= Inside T1 is the hot zone temperature, T2 is the cold zone temperature, the refractory temperature Rth = Rjv + Rvr + Rra is calculated by - In heat problems often give us know Tjm, Ta, Rth, ∆P It is required to determine whether to be cooled by natural convection or by how much the fan must be cooled m/s 15 Figure 2.5: a)Vol-ampere characteristics b ) Curve representing radiator blade heat and cooling fan speed c) Curve representing the radiator fins resistance and the medium With the above data, we choose heat dissipation by convection radiator Have T1 = 155 oC, T2 = 30 oC, ∆P = 125 => Rth=1oC/W So we can choose the type of heatsink below: Figure 2.6: Standard heatsink 2.5 Amplified control signals for IGBTs 16 To amplify the IGBT control signal, there are options: Pulse transformer Dedicated IC Transistor -Amplification by pulse transformers is capable of isolating, but difficult in usage and fabrication - Transistors amplification is more compact than a pulse transformer, but only for small power circuits - Amplifying with a dedicated IC for this circuit uses IC IR2110 that both responds to large frequencies and is quite easy to use without requiring in-depth knowledge 17 CHAPTER3: DESIGN THE CONTROL CIRCUIT 3.1 Structure of inverter control circuit: Pulse generation Pulse distribute Determine lead area Pulse amplifier Go to MOSFETS Figure 3.1 Inverter control circuit’s structure  Blocks’s function : - Pulse generation block: to make sync signal for hole system with the frequency is proportional to the fundamental harmonic of out voltage - The pulse distribute block: distribute pulse signal into individual valve following the working order of working priciple - Determine lead area block: make the valve working with specifically control method - Pulse amplifier: increase the power to open/close the valve 3.2 -phase inverter control circuit: Pulse amplifier Pulse generation Pulse distribution Pulse amplifier Figure 3.2 1-phase inverter control structure Control circuit for this type just has step to generate rectangle pulse for U fx, after that it’s goes through the frequency division step to make sure lead area valves are completely equal and reverse phase Before the power being amplified, we need to make a open delay to prevent short circuit of two valves in line 18 With it’s application, this kind of control circuit can be very easy to use by using simple pulse-number technique, with the oscillate generation step and voltage divide step using Flip Flop circuit at binary counting mode with Uoscillator=2*Uout 3.3 Synchronous - Select the synchronous circuit two half cycle: Figure 3.4: Synchronous circuit diagram The two half-cycle rectifier circuit has a midpoint using diodes D1, D2 and the rectifier load is resistor R0 The rectifier voltage Ucl after being created is brought to the (+) pole of the Opam to compare with (because the (-) pole of the opam is grounded) If Ucl> then Udb is equal to the saturation voltage (Ubh) If Ucl> then Udb is equal to the negative saturation voltage (-Ubh) The point of intersection of Ucl and is the transition point of the output voltage Figure 3.5: Oscillation graph synchronous circuit diagram 19 3.4 Stitch creating serrated Hình 3.6: Circuit Stitch creating serrated Activities: + When Udb < then D3 guide; so UR4 = Udb Udb = UC1 When the voltage reaches the threshold of Dz voltage diode, it will keep the output voltage at this voltage stabilizer (if there is no Dz ⇒ UC increased to + Udb) + When Udb > then D3 block Capacitor is launched UC dropped to and Dz keep UC in value - 0,7 - Calculation: Cycles: T = / f = 0,02 (s) = 20 (ms) select OA species TL082 The control angle range is 168 degrees Capacitor C launch time: = = 9,33 (ms) Choose the voltage regulator diode BZX79C has UDZ = 10 (V) Select capacitors C = 220 (nF) select R6 = 51k serial variable resistor P1 = 8k Time capacitor C loaded: tn = T/2 – = 10 – 9,33 = 0,67 (ms) The saturation voltage of the OA: Udb = E – 1,5 = 12 – 1,5 = 10,5 (V) So select R4 = (k) 20 Figure 3.7: Oscillation graph Circuit Stitch creating serrated 3.5 The comparison stage Function: Compare the control voltage with the restraint voltage to determine the timing of the control pulse ⇒ Determine the control angle α The comparison stage can be done with an element such as a transistor, or an OA algorithm amplification - We use the OA element because it allows to ensure the highest accuracy is to use dedicated OA coparator, with low cost, without complicated adjustment - Comparison using two-door OA: Hình 3.8: Comparison circuit The two voltages to be compared are applied to two different poles of the OA 21 In the above case Uđk = U +, Utua = U If UDC> Ura ⇒ Ura = + Ubh If Uđk