The Open Distribution System Simulator, OpenDSS
Copyright (c) 2008-2014, Electric Power Research Institute, Inc.
All rights reserved.
The 7.6 version is the first to be delivered in both 32-bit (X86) and
64-bit (X64) versions. The OpenDSSInstaller download includes both, along
with optional documentation and examples.
If you have 64-bit Windows, you may install both the 64-bit and 32-bit
versions. The 32-bit version is required if you plan to automate OpenDSS
from Excel or any other 32-bit program. The 64-bit version is required to
automate OpenDSS from MatLab on a 64-bit system.
The installer will give you a choice to install the executables and
optional files under a target directory of your choice, such as
c:\opendss. Files that are specific to the 32-bit version will be written
to an x86 subdirectory, such as c:\opendss\x86. Files that are specific
to the 64-bit version will be written to an x64 subdirectory, such as
c:\opendss\x64. The EXE and DLL files should not be moved after
installation, but may be updated in place with newer versions.
On a 64-bit system, you may install and use both the 32-bit and 64-bit
versions with no conflict between them.
Short-cuts to the program and manual are created under Start Menu/OpenDSS.
Please see the manual, OpenDSSManual.PDF, for an overview of the program.
The most up-to-date reference information will always be found through the
software's "Help / DSS Help" menu command.
The COM Server in OpenDSSEngine.DLL may be automated. The installer will
register either or both versions, depending on your selection. Even
though the file names and registration commands match, they are in
separate locations and Windows will activate the correct version required
by the calling program. For example, 64-bit MatLab will call the 64-bit
OpenDSSEngine.DLL and 32-bit Microsoft Excel will call the 32-bit version.
(Note: The 64-bit version of Excel is rarely installed.)
The OpenDSS is a simulator specifically designed to represent electric
power distribution circuits. OpenDSS is designed to support most types of
power distribution planning analysis associated with the interconnection
of distributed generation (DG) to utility systems. It also supports many
other types of frequency-domain circuit simulations commonly performed on
utility electric power distribution systems. It represents unbalanced
conditions, stochastic processes, and other aspects of electrical power
distribution systems and equipment in far greater detail than many other
tools, including commercial products. Through COM and scripting
interfaces, other programs can drive OpenDSS in highly customized
simulations, Monte Carlo analysis, etc. Users can define their own models
through dynamic linking, scripting, or automation.
Electric Power Research Institute, Inc. (http://www.epri.com) uses
OpenDSS in its research and services work, and continues to enhance the
software. Earlier proprietary versions were used in dozens of studies for
electric utility clients, and in a Web-based wind power simulator at
http://www.uwig.org/distwind. There are several goals in making OpenDSS
an open-source project at this time:
1 - Enhance the modeling capabilities available to government
laboratories, universities, and other researchers engaged in grid
2 - Encourage interfaces between OpenDSS and complementary tools, such as
communication system simulators or model compilers.
3 - Encourage the adoption of items 1 and 2 into commercial products used
by electric utilities.
4 - Encourage collaborative efforts between industry, government, and
university researchers in power distribution system analysis for grid
5 - Provide a capable testing platform for data and object modeling
efforts currently underway in the electric utility industry, at
http://cimug.ucaiug.org and http://www.multispeak.org.
The programming language for OpenDSS is Delphi
(http://www.embarcadero.com), currently version Delphi XE. There is also
a Free Pascal version of the program. Some of the supporting modules may
require a C++ compiler to build from source. OpenDSS source code is
available from the following SVN repository:
KLUSolve.DLL is open source software, available from
Other convenient Sourceforge.net Links
Links on EPRI's Smartgrid page:
OpenDSS Download Files:
IEEE Test Cases
Top level of Distribution area (Releases)
Use of this software is subject to a license. The terms are in:
1 - A file called "license.txt" distributed with the software,
2 - The user manual, and
3 - The executable program's Help/About dialog box