Internet, Open-source and

Power System Simulation

Mike Zhou

InterPSS Project Architect

mike@interpss.org

2

Agenda

• InterPSS Project• What is it? (demo)

• A Real-world Story

• Power System Simulation• The InterPSS Approach

• Open-Source• InterPSS – open-source, free

• Built on open-source

• Internet• Distribution, development and collaboration

• Summary

3

InterPSS Project

• InterPSS – An Internet Technology based Power System

Simulation Software (demo)

• Research Work Started 1995

E.Z. Zhou, ‘Object-oriented Programming, C++ and Power System Simulation’,

IEEE Transactions on Power Systems, Feb. 1996

• Formal Development Started 1/2005• No full-time developer

• Java - programming language

• No legacy code

• Current Release V1.2.01• Free usage for any purpose

• Most of source code are open

• 3000+ downloads

4

A Success Story

• The Problem• Unexpected Trip of 500MW Combined cycle plant caused by lost

of a large generation station in the network

• All standard tests failed to explain the problem

• InterPSS Simulation• Controller modeling - Controller Modeling Language

• Machine modeling - Dynamic bus device scripting

• Problem identified - Load angle limiter <-> PSS

• Proposed prevention solution verified by simulation

• Plant hardware changed and tested

• Actual field test• Simulation results convinced the network operator

• System-wide drop load test

• InterPSS used to determine reserve capacity

• The field test verified that the problem has been solved and the

accuracy of InterPSS simulation results

5

InterPSS Design Goal

“InterPSS’ open and loosely coupled system

architecture will allow components developed by

others to be easily plugged/integrated into the system

to augment its functionality, and equally important,

allow its components to be integrated into other

systems to provide certain power system simulation

functionality or service.”

• Software Engineering Approach

• Flexibility and Extensibility

• Usability

6

The Plugin Approach

Strongly Coupled

Application Suite

Other Approaches

A monolithic application with

a few things added

Plugins

InterPSS Core lib (<1M)

InterPSS Approach

A tiny little library to which

many things are contributed

and added

7

Power System Simulation Model

• InterPSS – Node/Branch object model for simulation purpose

• Automatic Code Generation

8

Transient Stability Simulation

• Software Design Pattern – Inversion of Control (IoC)

9

CML – InterPSS Controller Modelling Language

Σ

v

v

v

x efd

ref

pss

t

+

-+

K

1 + Ts

v

v rmin

rmax

@AnController(

input="this.refPoint + pss.vs - mach.vt",

output="this.delayBlock.y",

refPoint="this.delayBlock.u0-pss.vs + mach.vt",

display= {"str.ExciterState, this.delayBlock.state"}

)

public double k = 50.0, t = 0.05, vmax = 10.0, vmin = 0.0;

@AnControllerField(

type= CMLFieldType.ControlBlock,

input="this.refPoint + pss.vs - mach.vt",

parameter={"type.Limit", "this.k", "this.t", "this.vmax", this.vmin"},

y0="mach.efd" )

DelayControlBlock delayBlock;

DSL – Domain

Specific Language

-> Compile to Java Bytecode on-fly

10

Open-source Tools and Libraries

• Eclipse and NetBeans IDE• Project development environment

• Eclipse EMF - Automatic code generation

• JGraph - InterPSS graphic editor

• Spring Framework – integration and extension

• JasperReport - InterPSS reporting

• JFreeChart - Charts and plots

• Castor - Java object <-> Xml document binding

• Apache Derby Database• User and reference data

• Simulation results

• Apache iBatis - Object Database persistence• …

11

Internet & InterPSS

• Desktop Edition

• Web Edition

• JSP Front-end

• Applet for One-line diagram

• New trand• Adobe Flex

• Microsoft SiverLight

12

Manage Complexity - Virtual Development Workplace

Internet

Home.interpss.org

Google Services

US

Canada

Wuhan

Changsha

Sourceforge.net

InterPSS Wiki

InterPSS User Acceptance Testing

InterPSS File Service

InterPSS Web Site

InterPSS Code Repository

InterPSS Email service

InterPSS Issue Reporting

InterPSS Discussion Group

InterPSS Download

China

China

13

Collaboration - InterPSS Wiki

1. A Wiki site for InterPSS user community

2. User can create documents, tutorials

3. Also serves as InterPSS project portal

14

FitNesse Based User Acceptance Testing

1. User can create test cases

2. User can participate in the acceptance testing.

3. User can upload components to test against InterPSS library

4. User can run regression tests against any new development

15

A Changing World

P-1

P-n

Many years ago

Domain Expert

.

.

.

Commercial

Vendor

P-1

P-n

P-1

P-n

Common Function

Open-source

P-1

Domain Expert

P-1

Common Function

Open-source

P-n

Commercial Vendor

Open-Source

Promise