Network Reduction Toolbox

Graphics created using PowerWorld with Energy Visuals data.

The network reduction toolbox performs modified Ward reduction. Two input files are required by the toolbox: the (original) full power-flow base-case model in MATPOWER format and a user-defined list of the external bus indices, i.e., buses to be eliminated.

The output of the toolbox includes three files: a reduced power-flow model file in MATPOWER format; a file providing the new generator-to-bus assignment, which lists to which buses the external generators are moved; and a branch circuit number file indicating which branches are equivalent lines.

For details about the input and output, please refer to the help files of the functions. Every function in the toolbox has a help file that describes its purpose and the format of the input and the output data.

  1. Components
    The package includes two components:
    a) The reduction software, including all subroutines to generate the reduced model.
    b) An example file which can be used to demonstrating network reduction on a 9 bus system. To run the example, please open and run the file Example_9bus.m. This file generates a reduced model of a 9 bus system by eliminating 3 buses. A more detailed description of the reduction process and output files are included in the file.
  2. Installation
    To install the toolbox please download the package and add the path to the directory to which the toolbox was downloaded.
  3. How to use
    The basic steps to using this software are:
    a) Read in the input full model data using the feval function (a MATLAB built-in function).*
    b) Generate a list of external bus indices.
    c) Call subroutine MPReduction to perform the reduction and generate the output files listed above.

* If you have already installed MATPOWER, you can use the function loadcase instead to read the input full model.


We request that those using the generator data or toolbox for their research please cite the following reference:

D. Shi, D. Shawhan, N. Li, D. J. Tylavsky, J. Taber, R. Zimmerman, “Optimal Generation Investment Planning: Part 1: Network Equivalents,” North American Power Symposium 2012 (electronic journal), September 2012, pgs. 6.