Pratical classes Laboratory classes. Evaluation: 3 Exercises sets (1 every other 3 weeks) - 30% Reports of laboratory works - 20% Final exam - 50%

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1 Function: Theoretical classes Pratical classes Laboratory classes Evaluation: 3 Exercises sets (1 every other 3 weeks) 30% Reports of laboratory works 20% Final exam 50% Bibliografy: Contacts: Slides supporting theoretical classes Laboratory guides Problems colecction to practice Books Beatriz Vieira Borges (responsável) bborges@lx.it.pt

2 Course Contents: 1. Introduction to Power Electronics 2. Electronic Devices 3. Circuits with Diodes and Switches 4. Transient and steady state circuits behaviors and energy recover. 5. AC/DC (rectifiers): Noncontrolled rectifiers Phase controlled rectifiers PWM rectifiers (with sinusoidal input current) 6. DC/CC converters: Basic Topologies Operating principles Switch Mode Power Supplies Converters Modelling 7. High frequency inductors and transformers. 8. DC/AC Converters: Operating principles and modulation techniques 9. Switching Audio Amplifiers 10. Resonant Switching Techniques

3 Power Electronics Converter Input Power Electrical Source DC or AC POWER CIRCUIT LOAD Output Power comando Source Signals Data CONTROL CIRCUIT Feedback POWER CIRCUIT devices semiconductor Input and output filters power transformer protection circuits CONTROL CIRCUIT electronic devices and circuits necessary to the proper regulation and command of the converter

4 High efficiency High Power Density [W/cm3] or [W/inch3] P I Electronic Converter P O When efficiency is low there is great termic dissipation inside the converter. The generated heat must be extracted to the outside, by means of heatsinks h=p O /P I Loss of Reliability Higher Dimensions (heatsinks)

5 Electronic Devices working in conduction and in cut off I D VDS CONDUCTION CUTOFF V DS =0 I D =0 P D =I D *V DS =0 Use of nondissipative components linear switching X X

6 V I=100V DCDC Converter I O R=5W V O=50V Variable Resistor h=50% V I=100V Linear V I=100V Semicondutor h=50% Power Losses=500W Power Losses=500W I O =10A R=5W I O =10A R=5W V O=50V V O=50V X X

7 Switching Converter h=100% V I =100V i I 1 2 v S (t) FILTER I=10A R V O V O 1 T T 0 v S t dt DV I V I v S (t) V O =DV T DT (1D)T

8 V I 1 2 L V I C R V O Switching Converter V I i I L C i C R V O feedback Transistor Drive d(t) PWM v e compensator G(s) DT T t v e (t) v Ref Reference Voltage t Control Circuit

9 Converters Classification according to the input and output waveforms of the voltages and currents ACDC Converters rectifiers ACAC Converters DCDC Converters DCAC Converters inverters

10 ACDC v O v V O(av) natural commutation i O i O wt DC a p 2pa wt AC i I v I c a r g a v O v AK1 wt v 1 2 sint a 2pa wt i I pa wt i O >0 e v O >0 ou < 0 wt

11 Power Electronics io ACDC Converters v1 2 sin t ii vi Drive Circuits c a r g a vo PulseTransformers Input voltage sampling transformer Controller

12 ACAC Converters natural commutation v O v V O(av) = 0 i O CA i O wt CA v I carga v O a p 2pa wt v 1 2 sint v AK1 wt i O >0 ou < 0 e v O >0 ou < 0 a pa 2pa wt wt

13 Power Electronics io ACAC Converters Natural Commutation CA drive circuits identical to the rectifiers ones vi v1 2 sin t carga vo CA

14 DCDC Converters Forced commutation CC CC v I v O i O c a r g a i O v O t on T t v 1 V I t on T t

15 Power Electronics DCDC Converters Forced commutation Power Circuit io v1 VI vi vo Control Circuit c a r g a

16 DCAC Converters Forced commutation v 1 V I DC v I i O AC carga v O i O v I v O v I T/2 T/2 T T t t i O e v O > or < 0

17 Power Electronics DCAC io vi Converters R io e Power Circuit Control Circuit S vo > ou < 0 T

18 Power Electronics Special Converters ii VI L il n:1 vl S vo(t) R ideal CC ic D CA CC C Power Circuit High Frequency Switching power Supply DCAChfDC Freq. [100kHz] Power<100W h<85% Control Circuit

19 Special Converters ACDC DCAC hf DC SMPS with power factor correction w i I t v I w t i Iav (w t) v i I v I 1 2 AC DC sint DC n:1 L il v L D ideal S AC hf DC i C C R v O (t)

20 Power Electronics Special Converters VI ii L il n:1 vl vo(t) R ideal S ic D LS Quasi Resonant Power Supply CS C ZVS (buckboost) Zero Voltage Switching Power Circuit CCCAhfCC Frequency: [1MHz] Control Circuit Power<50W h<95%

21 Power Electronics Special Converters PWMResonant Switching Power Supply Zero Voltage Switching Power Circuit DCAhfCDC Frequency: [250kHz] Control Circuit Power<1kW h=97%

22 Power Electronics Audio Switching Power Amplifier Special Converters Power Circuit ACDCAhfCAC Frequency: [132 khz] Control Circuit Power<2kW h<80%

23 Switching processes: Natural commutation: When in a circuit, conditions are created, so that a device can pass from conduction to cutoff without any action from outside. These conditions are created by infuence of the mains or by influence of the load, and by means of turning on another device or by actuating in the gate terminal of the semiconductor. source commutation load commutation i T i T i T i T i G t i G t t t

24 Forced commutation When it is necessary to actuate at the gate terminal of the device to pass it from the state of conduction to cuttoff. V R L i T i G t t natural forced line (devices commutate due to the ac behavior of the input voltages) line frequency converters load (the load makes the current to oscillate in the switch. load commutated converters switching converters

25 Power Electronics ACDCConverter P v I 2V I sin t v O V O n1 a n cos nt n1 b n sin nt v I N v O v O v I Ideal v O =V O N P Filtering DCAC Converter P vi V I v O n1 a n cos nt n1 b n sin nt N v O v I v I v O Ideal v O =2 V O sin wt N P Filtering

26 Power electronics basic procedures: Do not connect in series current sources with different current values. Do not connect in parallell voltage sources with different voltage values. Do not open inductive circuits. Do not shortcircuit capacitive circuits. If the input is a voltage source, the output must have current source characteristics (load in series with an inductor). If the input is a current source, the output must have voltage source characteristics (load in parallel with a capacitor). Incompatabilities Elimination by insertion of reactive adaptative elements: Insertion of C to open na inductive circuit V L R open V L R Insertion of L to connect two voltage sources in parallel V C R close V L C R

27 Power semiconductor devices: 1. Diode A K 2. Thyristor (SCR) Silicon Controlled Rectifier. A G K 3. Gate Turn Off Thyristor (GTO). A K E C G 4. Bipolar Junction Transistor (BJT). B C B E D D 5. Field Effect Transistor (MOSFET). C G S G S 6. Insulated Gate Bipolar Transistor (IGBT). A G E 7. MOS Controlled Thyristor MCT. G K

28 Diode A K Turns on when the voltage at it s terminals, v AK, becomes positive. Turs off when it s current, I F, becomes negative. Diode Ideal Characteristic I F V AK

29 Tiristor A K G Turns on if v AK becomes positive and if a low duration current pulse is present at its gate terminal. Blocks if the current I F becomes negative Thyristor Ideal Characteristic I F only TurnON Control V AK A K I AK G i G I F v O v V O(av) blocking turnon v AK wt i G V AK a 2pa wt

30 MOSFET D G Totaly controled. Turns on if v GS is positive. S Blocks if v GS becomes null or negative. MOSFET Ideal Characteristic I D V DS

31 IGBT Freq. [20 khz] G C Totally controlled. Conducts if v GE is positive. E Blocks if v GE becomes null or negative. IGBT Ideal I C Characteristic V CE

32 High Frequency Transformers v 1 v 2 Ferrite core v1 v 2 i i 2 1 N N 1 2 N N 1 2 i 1 i 2 v 1 v 2 ideal

33 High Frequency Transformers Equivalent circuit i 1 v 1 L l1 i m L m i 1 i 2 N 1 :N 2 L l2 i 2 v 2

34 High Frequency Transformers i 1 v 1 L l1 i 1 i 2 N 1 :N 2 L L l2 N 2 N1 2 i 2 v 2 This image cannot currently be displayed. L m = infinite L l1 e L l2 = 0 (magnetizing inductance) (leakage inductances)

35 PE is a multidisciplinar subject that implies the study of various areas: Circuit Topologies, Semiconductor Devices, Modelling and Modulation Techniques, Control processes and its characterization, Filtering Techniques and Harmonic Suppression, etc. COMPUTOR ADDED DESIGN CAD DIGITAL AND ANALOG ELECTRONICS TOPOLOGIES POWER ELECTRONICS ELECTRICAL DRIVES CONTROL POWER SEMICONDUTOR DEVICES REGULATION AND CONTROL VLSI INTEGRATED CIRCUITS mcomputors mprocessors

36 APPLICATION FIELDS/ EMERGENT AREAS Computers and periferals Power supplies Telecomunications Aerospacial Sistems Electrical Drives Frequency converters Ele tronic ignition Automobile Industry Electronic sbalas Control of Lightening Lightening Renewable energies Prof. Pedro Santos

37 Aplication Tecnológical Areas de / emerging areas Power semiconductors Power modules PIC Power Management DC/DC Modules Passive components Magnetic materials/ cores Protections HVDC Power Distribution Thermal Management casing (EMC) Simulation & modelling Regulation & Control Converter Topologies Prof. Pedro Santos

38 Products and systems involved in PE Power Semiconductors Darlington Modules Diodo/tiristor Modules (hybrid) IGBT Modules Smart Power IC e PICs Power Diodes MOSFET Modules Motor Drivers Static relays IC Converters Applicationoriented ICs OptoSemiconductor Components Sensors & Microsystems Electrical and Magnetic variables sensors Temperature sensors Microactuators 2003 Passive components L C R Transformers (isolation, HF,...) cores, ferrites, magnetic materiais coils Thermal management Heatsinks Radiators & frisers Fans Peltier Elements Prof. Pedro Santos Supplies HFTransformers DC e AC power supplies Frequency converters UPS Stabelizers Laboratory supplies Batteries Power Management Systems DC/DC converters modules CAD Tools Development Software Simulation Software Test Software Specific Application Software.

39 APPLICATIONS INDUSTRIAL: Compressors; Fans Tool Machines (Robots) Induction Heating Lightening Lasers Welding Machines Electrchemical Processes. COMERCIAL: Heating, ventilation and air condicioned Cold equipment Lightening Computoes and office equipment Uninterruptible Power Supplies (UPS) Lifts. TRANSPORTES: Controlo e accionam. de veículos eléctricos de tracção Carregadores de baterias Locomotivas eléctricas Metropolitano Carros eléctricos, automóveis, etc. POWER SYSTEMS: High Voltage DC Current Transfer (HVDC) VAR Static Systems Renewable Energy Sources Energy Storage Systems. AERO SPACIAL INDUSTRY: Power supplies systems for aerospace. Satelites Power Supplies Systems Airplane Power Supplies Systems. TELECOMMUNICATIONS: Battery Chargers SMPS UPS. DOMESTIC APPLICATIONS: Fridges; Heating; Hovens Domestic electronics; Lightening.