OpenDSS is a freely-available, open-source electrical power system analysis tool used to simulate distribution-level power systems. It supports nearly all frequency domain (sinusoidal steady‐state) analyses commonly performed on electric utility power distribution systems.

In addition, it supports many new types of analyses that are designed to meet future needs related to smart grid, grid modernization, and renewable energy research.

OpenDSS has been used since 1997 in support of various research and consulting projects requiring distribution system analysis. Many of the features found in the program were originally intended to support the analysis of distributed generation interconnected to utility distribution systems and that continues to be a common use.

Other features support analysis of such things as energy efficiency in power delivery and harmonic current flow. OpenDSS is designed to be indefinitely expandable so that it can be easily modified to meet future needs.

For download information, documentation, and test cases, please visit the EPRI Smart Grid Resource Center.