The Power

of Connected

Models at NGES

Date: 4/15/2015

Northrop Grumman Electronics Systems (NGES) Sector

Power Conversion Technology Department

Kerron Duncan

Outline

• Typical Power System using Saber Circuit Simulator by Synopsys

• ModelCenter® Wrappers

• Saber Wrapper Requirements

• Implementation

• Example Circuit: Parametric Sweeps and Optimization

• Cost, Size, Weight and Schedule Implications

• Trades and Analysis

• Summary

DC-DCPower Supply

Saber Circuit Simulator Used

For Power System Design/Analysis

Load

DistributionAC-DC

ConverterSource

Electrical Circuit Simulator

Thorsten Gerke, “Validate electronics robustness: Part 2-Find the worst case” EE Times, 11/19/2010

A Typical Power System…

ModelCenter® Out-of-Box “Wrappers” Link Together & Add Functionality

4

Numerous Others

600

535.556

471.111

406.667

342.222

277.778

213.333

148.889

84.4444

20

response (Model.Matlab.capcost)

vdroop

21.951.91.851.81.751.71.651.61.551.51.451.41.351.31.251.21.151.11.0510.950.90.850.80.750.70.650.60.55

ca

pc

os

t

590

580

570

560

550

540

530

520

510

500

490

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460

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390

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190

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90

80

70

60

50

40

30

20

109.8

9.69.4

9.29

8.88.6

8.48.2

87.8

7.67.4

7.27

6.86.6

6.46.2

65.8

5.65.4

5.25

4.84.6

4.44.2

43.8

3.63.4

3.23

2.82.6

2.42.2

21.8

1.61.4

1.21

Design of Experiments

Surface Plots

Optimization

The “QuickWrap” Function Creates Connection to Saber Circuit Simulator

5

Numerous Others

Gain the capabilities of the detailed circuit simulator

“Wrapping” Saber with ModelCenter

• What is the added functionality?

• What are the manual steps?

• How can we automate this process?

6

ModelCenter

Netlist Schematic

Run Analysis

Calculate ResultsAnd Figures of

Merit

Export resultsSend output data to ModelCenter

Send Commands

Send new variable values to Saber

Wrapping Saber Process Overview

7

SaberCircuit

Simulator

Output File

ModelCenter

Script

Wrapper

Links to ModelCenter

ModelCenter Linked To Saber

Saber Output Linked Back To ModelCenter

Netlist (Design)

Command File (Invoke)

Simulation (Analyze)

Example Saber Schematic7th Order Chebyshev Filter

8 8

Vout

Example Filter Response -20 dB Threshold Point Defined as Figure of Merit

9

-20 dB Threshold

Vout (dB) vs. Frequency

Figure of Merit (FOM) = MHz

FOM(MHz)

QuickWrap Created to “Wrap” Saber

10

InputsOutputs

(FOM)

QuickWrap Invokes Saber:

-Vary Parameter Sets

-Run an analysis/simulation

-Export the results when done

Matlab used for unit

conversion and post

processing of results

QuickWrap Interface Window

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INPUT File:

Filter Schematic Netlist

OUTPUT File:

Simulation Data

Run File:

Command.exe

Parameter Sweep (L1) w/ ModelCenter + Saber

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FOM(L1)Vary L1

Figure of Merit (FOM) measurement when Vout(dB) = -20 dB point MHz

ModelCenter Parameter Sweeps Matches Saber

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Notes:

ModelCenter accurately creates parameter sweep curves and values

3.8 MHz @ L1 = 3uH

2.4 MHz @ L1 = 20uH

2.8 MHz @ L1 = 10uH

Figure of Merit vs L1 Values

FOM (Hz)

Sweeping L1 (H)

Optimization Problem for Filter Design

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MHzXCCCLLLptdB ),,,,,( FOM 321321_20

BLLLA 321 ,,

Objective:

Constraints:

Design filter s.t. -20 dB pt equal 5 MHz

DCCCC 321 ,,

QuickWrap Allows

Parametric Sweeps and FOM Optimization

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Optimizer tool used for circuit

element optimization of FOM

QuickWrap invokes

Saber to run an

analysis and export

the results

Matlab used for unit conversion

and post processing

ModelCenter + Saber + Matlab Optimized SolutionOptimized Run Solution Found at N=233 runs, FOM = 5 MHz

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MHzCCCCLLLptdB 5),,,,,,( FOM 4321321_20

Notes:

FOM reaches convergence after 223 runs

FOM

Run Number

Including Disparate ModelsCost and Weight Spreadsheet

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Cost, Weight vs L, C Values

Excel Database

of Inductor Costs and Weight

L,C ValuesFOM

$,Weight

DOE of All Parameters

Optimized Solution AchievedFOM = 5 MHz, Minimized Cost and Weight

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FOM

Run Number

MHzCCCLLLptdB 5),,,,,( FOM 321321_20

BLLLA 321 ,,

Objective:

Constraints:

Design filter s.t. -20 dB pt equal 5 MHz

DCCCC 321 ,,

)min($,Weight

Cost &

Weight

Optimized

Minimized

Summary

• We demonstrate the following using ModelCenter + Saber

– To modify Saber netlist values and analyze a Chebyshev filter design

– Calculate a figure of merit for the filter response

– Parameter sweep the design and generate parameter curves

– Optimize the design given a problem statement and constraints

– Introduced cost and weight into the model based design

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+

Author Biography

Kerron Duncan received his B.S. and M.S degree in Electrical

Engineering from Morgan State University in 2000 and 2003,

respectively. He joined Northrop Grumman ES in 2001 and is currently

manager of Power Systems & Control group in the Power Conversion

Technology Department. He is also pursuing a PhD at Johns Hopkins

University in the area of wireless biotelemetry trade space modeling

and simulation and is interested in system architecture models which

include “push factors” for various subsystems such that their

interdependences (size, weight, cost, power) with respect to

performance that can be used in model based engineering efforts.

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