EE155/255 Green Electronics

Transcription

1 EE155/255 Green Electronics Quiz Review 11/14/16 Prof. William Dally Computer Systems Laboratory Stanford University

2 Quiz is next Wednesday 11/16 7:00PM to 9:00PM Room Covers all material to date One page of notes allowed Sign off last lab last week Course Logistics Now in the project part of the course Checkpoint 1 today send the course staff a progress report What you have accomplished Any problems you encountered and how you dealt with them Any revisions to your original plan PCB review by checkpoint 2 Order parts and PCBs ASAP

3 YAH

4 Quiz Review

5 Periodic Steady State

6 Buck Converter V a b L i L + - V 2

7 Dual-Source Buck b a c

8 Isolated Converters

9 Ideal Transformer I P 1:N I S + + V P V S V S = N S N P V P I S = N P N S V P An ideal transformer w

10 Real Transformer L L i PR i P 1:N i S V PR V P L M i M V S ideal xfmr

11 Full-Bridge Converter i P i S a b + V 1 a b + V P 1:N + V S c d c d + V R i L L C + V 2 inverter transformer rectifier output filter

12 Full-Bridge Converter UL UR LL LR EE 155/255 Lecture 8 - Isolated Converters

13 Periodic Steady State Analysis of Full Bridge Suppose V 1 = 10V, transformer is 1:10, what duty factor gives V 2 =50V (ignoring leakage inductance) Now if primary referenced leakage inductance is 10µH i L = 10A, t cy = 10µs, what duty factor is needed?

14 Flyback Converter i S + + 1:N + b + i M L M V P V S C V 2 V PR x V 1 + L L i L EA a EE 155/255 Lecture 8 - Isolated Converters

15 Flyback Converter With L M and L L and Transformer Eliminated i M L M CN V 2 N x i S + V 1 + L L i L EA a EE 155/255 Lecture 8 - Isolated Converters

16 Flyback Converter Assume no leakage inductance Magnitizing inductance is 50uH Input voltage and output voltage both 100V If 1A load current, 16us cycle time, and 1:1 transformer How long an on period is required?

17 Motor Control

18 Motor Equations V = L (v x B) V = K M w F = i(l x B) t = K M i t = I M (dw/dt) Simultaneously both a motor and a generator

19 Back EMF 1 N V(a) = -Kwsin(q-a) Open-circuit voltage (back EMF) of each phase is a sinusoid that 3 S 2 Is proportional to w Reaches peak value when rotor is 90 degrees from phase.

20 Torque t = -(Ki)sin(q-a i ) 1 Torque is proportional to current N Torque is maximum when rotor is 90 degrees behind phase 3 S 2 Torque from each phase is sinusoidal

21 Example Suppose K M =1, R M =1, q=30deg, w=10rad/s, V=100V What duty factor should be applied to each phase to give 1N-m torque?

22 Three-Phase Explained Graphically Sin(q-f i ) Current Sin 2 (q-f i ) Torque SSin 2 (q-f i ) Sum of Torque over phases

23 Control

24 Consider the Following Plants 1 s + a 1 s 2 +2!s +! 2 What type of controller do we need for each? What should the parameters of our controller be?

25 Bode Plot for z=0.1 w= Bode Diagram Gm = Inf db (at Inf rad/s), Pm = 3.8 deg (at 3.31e+03 rad/s) 30 Magnitude (db) Phase (deg) Frequency (rad/s)

26 Approach 1 Integral Only Low Gain 40 Bode Diagram Gm = 66 db (at 1e+03 rad/s), Pm = 90 deg (at 0.1 rad/s) 60 Magnitude (db) Phase (deg) Frequency (rad/s)

27 Approach 2 PDI Large Gain Compensating Zero 100 Bode Diagram Gm = Inf, Pm = 89.5 deg (at 1e+05 rad/s) 80 Magnitude (db) Phase (deg) Frequency (rad/s)

28 Switches

29 50A 45A 40A 35A 30A DC I-V Characteristics of On Switches 60V FET IRLB3036 Diode and IGBT Resistive at high Current 400V Diode STTH20R04 Ix(m:1) Ix(h:2) Ix(i:C) I(Dd) 600V IGBT FGH40N60 25A 20A 15A 10A 5A FETs Characterized By R ON 600V FET FCB36N60 HV FET has high RON R ~ kv 2 0A 0.0V 0.1V 0.2V 0.3V 0.4V 0.5V 0.6V 0.7V 0.8V 0.9V 1.0V 1.1V 1.2V 1.3V 1.4V 1.5V 1.6V 1.7V 1.8V 1.9V 2.0V V(d) IGBT Like a Diode Little Current Until ~0.7V

30 10KW 9KW 8KW 7KW 6KW 5KW 4KW 3KW 2KW 1KW 0KW 550V 500V 450V 400V 350V 300V 250V 200V 150V 100V 50V 0V 550V 500V 450V 400V 350V 300V 250V 200V 150V 100V 50V Transient Response of FET and IGBT ix(i:c)*v(di) ix(h:2)*v(dm) 36µJ 92µJ 36µJ 428µJ V(dm) V(di) 0V 0ns 40ns 80ns 120ns 160ns 200ns 240ns 280ns 320ns Turn On Instantaneous Power 600V FET FCB36N60 600V IGBT FGH40N60 Turn Off Ix(h:2) Ix(i:C) 20A 15A 10A 5A 0A 20A 15A 10A 5A 0A

31 Turn-On Buck w/ Diode I D I P I L Q RR Q D s t 1 ramp current to I L t 2 diode reverse recovery t 3 discharge drain capacitance V DS Current waveform in t 2 and t 3 may vary t 1 t 2 t 3

32 Turn-On Buck w/ Diode I D V DS I P Q RR Q D I L s t 1 t 2 t 3 t 1 = I L s E 1 = 0.5V DD I L t 1 = 0.5V DDI L 2 t 2 = 2Q RR s E 2 = V DD t 2 t 3 2Q D I P s I L + 0.5t 2 s ( ) E 3 = 0.5V DD Q D V DD I L t 3

33 Switches Calculate the switching energy during turn-on for a MOSFET switching 10A through 100V in a buck configuration. Drain capacitance is 1nF, QRR is 25nC. Current ramp is 1A/ns.

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35 Suppose a single PV panel has V OC = 40V, I SC = 8A, and P max = 250W PV You want to use this panel to provide a 5V supply with the maximum possible current (a) What converter topology should you use? (b) What variable should be regulated? (c) If losses are zero, what will be the maximum current out? (d) Will the panel be at its MPP when current reaches a maximum? (xc) What control law will provide maximum power beyond the point where 5V can be maintained? (e) What would your answers be if the output were 100V?

36 IV Curve from SPICE Model

37 Typical String of 10 PV Panels

38 Magnetic Components

39 A Magnetic Circuit Put N turns of wire on a magnetic core Pass current i through resulting coil Produces Magnetomotive Force F = Ni F induces a flux f in the core φ = F R = Ni R Where R is the Reluctance of the core Change in f causes voltage V = N dφ dt

40 Two Key Equations

41 Inductors Suppose inductor for a converter with L=6.25uH and I max =11A has A c = 1E-4m 2 L c = 1E-2m µ = 1000 f = 100kHz B max = 0.1T What gap is needed? How many turns?

42 Transformers V = N d dt L L i PR i P 1:N i S VT = N V PR V P L M i M V S ideal xfmr VT = NBA N = VT BA

43 Soft Switching

44 Only switch a FET when: Zero voltage across it (ZVS) Zero current through it (ZCS) Both Soft Switching 4 Approaches Phase-shifted full-bridge Quasi-square wave Quasi resonant Active clamp

45 QSW Buck Converter V S + - H M 1 D 1 L i L + L M 2 D 2 C X C v C Load i Load -

46 Soft Switched Waveforms

47 Quasi-Resonant ZCS Buck D 2 M 1 L r L V S + - H i r C r D 1 i L C + v C Load i Load - Initially M1 off D1 on M1 turns on ZCS i r ramps linearly to i L D1 turns off ZCS & ZVS i r starts charging Cr (tank circuit) Peak voltage at 2V S C r discharges through L Pulse width fixed by i L and L r C r Control converter by varying frequency

48 v x (V) v c (V) i r (A) i L (A)

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50 Inverters and Power Factor

51 Definition PF = Real P ower Apparent P ower Apparent Power = V rms x I rms PF = P p P 2 + Q 2 PF = 1 p 1+THD 2 = I 1,rms I rms

52 Make a PWM Sine Wave and Filter

53 PWM Synthesis V AC, V Saw (V) V PWM (V) x = sine > saw y = -sine > saw Digitally generate sine with quarterwave table V Out (V) I L (A) t (ms)

54 Spectrum of 100kHz PWM Signal 9 x Mag f (Hz)

55 Batteries

56 Batteries L B R B + V BS V B -

57 Voltage Surface V(x,T,I) Discharge Discharge Temperature Characteristics for for NCR18650B1S NCR18650B 4.5 cell Charge:CC-CV:1.625A-4.20V(65.0mA cut) Discharge:CC:3.25A(E.V.:2.50V) 4.0 Cell Voltage / V Discharge Temperature Rate Characteristics Characteristics for for NCR18650B NCR18650B1S cell-1 Temp: Charge:CC-CV:1.625A-4.2V Charge:CC-CV:1.625A-4.20V(65.0mA cut) cut) Discharge:CC:Variable Discharge:CC:3.25A(E.V.:2.50V) Current (E.V.:2.50V) 4.0 / V Discharge Capacity / mah 2G23X0KYKU Cell Voltage CA 1.0CA 0.5CA 0.2CA Discharge Capacity / mah 2G23X0KYKU

58 Charge Cycle Charge Characteristics for for NCR18650B1S 4.5 No.1 Cell Voltage Charge:CC-CV:1.625A-4.20V(65.0mA cut) 5000 Cell Voltage / V Current Capacity Current / ma Capacity / mah Charge Time / min 0

59 YAH