The IEEE 118 Bus Test Case represents a portion of the American Electric Power System (in the Midwestern US) as of December, 1962. The data was manually entered from a copy of a copy of a copy, etc., of the AEP 118 Bus Test System document dated December, 1962 and "made available to the electric utility industry as a standard test case".) It was entered in PECO PSAP format by Rich Christie at the University of Washington in 1993. Please call any typos in the PSAP version to my attention.

It was later entered in IEEE Common Data Format by Rich Christie at the University of Washington in 1993. Please call any typos in the CDF file to my attention.

Most of the bus names in the file were obtained from the one line diagram distributed with the package. The names were in a small font, and after many generations of copying legibility was poor, so errors of transcription may have occurred. Other bus names are simply made up.

The base KV levels in the bus names appear to be a bad guess.

The line MVA limits were not part of the original data and are made up.

As a test case, this one has a lot of voltage control devices, and is quite robust, converging in 5 or so iterations with a fast decoupled power flow.

Rich Christie - May, 1993