Transient stability is the ability of a power system to maintain synchronism when subjected to a severe disturbance such as a fault, loss or addition of a large load, and loss of generation. Unlike small-signal stability, in transient stability a large-signal disturbance is considered. Therefore nonlinear differential equations of the system should be employed to represent the system.

In a transient stability study, the factors influencing stability, different load modeling approaches, and methods to improve stability of the system are discussed. Stable operation of a power system depends on the ability of system generators to meet active and reactive power demand of the loads. As a result, it is important to accurately represent the a load to capture the dependence of it real and reactive power on the system variables, e.g, bus voltage. Therefore, load modeling plays an important role in transient stability analysis

In this work, a software tool is developed to implement the simulation algorithm in MATLAB. The software is capable of representing several load and generator models and can handle the PSS/E native file format.

The m-code of the software and a description of its elements are provided in this website


  • Paper: (will be uploaded once accepted for submission)
  • Source code (m-code): A series of m-files, each implementing one major step of the algorithm. | 45 KB


  • Ali Mehrizi-Sani

    The Edward S. Rogers Sr. Department of
        Electrical and Computer Engineering
    University of Toronto
    SF1107 - 10 King's College Road
    Toronto, ON   M5S 3G4

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  • Last updated January 7, 2010.