EEL 5245 POWER ELECTRONICS I

Lecture #5: Examples

PSPICE Refresher (Dr. Chris Iannelo)

Discussion Topics

•  Exercise 2.2 and Problem 2.7 Solutions •  PSPICE Overview

–  PSPICE Websites •  www.pspice.com •  www.orcadpcb.com •  www.cadencepcb.com/products/downloads/default.asp

–  Any special libraries needed (if there are any) will be posted to the WebCT website

–  PSPICE File types •  *.SCH, *.LIB, *.SLB, *.CIR (SCHEMATICS EDITOR) •  *.OPJ, *.LIB, *.OLB, *.CIR (CAPTURE EDITOR)

Discussion Topics

•  Exercise 2.2 Exact Solution

•  Problem 2.7

Discussion Topics

•  Schematic Definition done in one of two editors provided: Schematics or Capture

•  In class examples use Schematics editor (you can use either Schematics or Capture as your editor of choice) –  Schematics often easier to use –  Capture editor has more built in functions –  Both create similar but slightly different text files

(netlists and *.cir files) for pass off to the PSPICE A/D Engine.

•  PSPICE Engine has integrated display called PROBE for results viewing

Discussion Topics

•  Schematics Front end –  Overview of Simulation Types

•  Transient, Bias Point, AC

–  Model Parameters (Model Editor and Attributes entry) –  Library Configuration (Symbol, Model, Include) –  Cut and Past Operations from PSPICE for Submission

and/or presentation –  Parts of Interest

•  Diode Options –  SBreak –  DBreak

•  Sources –  VPulse

Discussion Topics

•  Ideal Switch –  Sw_tclose, Sw_topen, SBreak

•  ABM Parts –  GValue, GTable, EValue, ETable

•  “Real World” Parts in Eval Library •  Diode Implementation

–  Marker Types –  Polarity in Schematics –  Append Functions in Probe –  Probe Setup Options –  Convergence Tips and Tricks

•  “Virtual Snubber” •  reltol=.01

Buck with no Low Pass Filter Transient Simulation

Time 0s 10us 20us 30us 40us

V(Rload:1) V(Control) 0V

10V

20V

30V

Time 0s 10us 20us 30us 40us 1 V(Rload:1) 2 V(Control)

0V

10V

20V

30V 1

0V

0.5V

1.0V 2

>>

Buck with no Low Pass Filter FFT

Frequency 0Hz 200KHz 400KHz 502KHz

V(Rload:1) 0V

5V

10V

15V

Buck with no Low Pass Filter Model Parameters of Sbreak

Buck with no Low Pass Filter PSPICE Generated Files

Buck with no Low Pass Filter Alias File

Buck with no Low Pass Filter Circuit File

Buck with no Low Pass Filter Library and Netlist File

Buck with no Low Pass Filter Probe file

Buck with no Low Pass Filter Adding a Library File

Buck with no Low Pass Filter Adding a Symbol Library

Buck with no Low Pass Filter The nom.lib File

Buck with no Low Pass Filter Complex Parts in Eval *.lib files

Homework Example 2.3 Unusual WaveShapes

Time 0s 5us 10us 15us 20us

V(R1:1) RMS(V(R1:1)) -20V

0V

20V (20.000u,6.9309)

Time 0s 20us 40us 60us

V(R1:1) -20V

0V

20V

Homework Example 2.3 Unusual WaveShapes- Diode Implementation

Time 8.00us 12.00us 4.54us 15.97us

V(Vo_Dbreak) V(Vo_Sbreak)

0V

5.0V

10.0V 12.7V

Time 14.600us 14.800us 15.000us

V(Vo_Dbreak) V(Vo_Sbreak)

0V

125mV

250mV

375mV

-96mV

Homework Example 2.3 Unusual WaveShapes- Diode Implementation

Time 8.00us 12.00us 4.55us 15.85us

V(Vo_Dbreak) V(Vo_Sbreak) 0V

5.0V

10.0V 12.6V

Time 14.4us 14.6us 14.8us 15.0us

V(Vo_Dbreak) V(Vo_Sbreak)

0V

200mV

400mV 506mV

Buck Converter (Step Down) CCM Open Loop Simulation

Time 0s 5ms 10ms

V(Output) I(L1) 0

12.5

25.0

37.5

50.0

Time 9.85ms 9.86ms 9.87ms 1 I(L1) 2 V(L1:1,L1:2)

1.5A 2.0A 2.5A 3.0A 1

0V

20V

-32V

2

V(Output) 24.4313V 24.4375V 24.4438V

Buck Converter (Step Down) CCM using Capture as Editor

+ -

+ -

S1

VOFF = 0.0VVON = 1.0V

ROFF = 1e6RON = 1p

Vpulse

PER = 10usPW = 5us

TF = .1nsTR = .1ns

+-

DbreakD1

Cf100uF

IC = 0V

RLoad10

Vin50V

+

-

L

750u

IC = 0A Output

Gate

Gate

99.88pV50.00V 49.95V

0V

VI

Buck Converter (Step Down) CCM using Capture as Editor

•  Library setup in Capture

Project Conversion Schematic files to Capture Files

•  Requires some effort •  Need original *.ini file from Schematics (often in C:

\windows directory) •  Can often use an ini that’s not the original but requires

user to modify the pspice.ini for the new front-end

PSPICE Case Study: Hubble Telescope Design

•  Attached is excellent example of how PSPICE can do both electronics level and system level simulations

•  Note how the authors use “time scaling” such that –  Simulation time 596 seconds on PC –  “PSPICE Time Span” 1.8 seconds –  Physical Time Span 1.8*10000 seconds=5 hours –  To improve the Pspice simulator convergence for multiple orbit runs, time is

divided by –  10000, resulting in a 96 minute orbit equal to 576 milliseconds, and a 60

minute daytime duration of –  360 milliseconds.