NEPLAN | Small Signal Stability

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The NEPLAN Small Signal Stability module offers eigenvalue analysis (modal analysis) for electrical power systems. It provides information about the inherent dynamic characteristics of the power system and assists in its design. It is typically used in studies of interarea oscillations. It combines exceptional ease of use with the latest techniques and standards in both electrical power engineering and software design.

General Characteristics

  • Data scanning and eigenvalue sensitivity functions
  • Automatic construction of the linearized state space notation for the complete system, including generators, static loads, control circuits, etc.
  • Advanced synchronous machine modelling. Selection for every synchronous machine of one of the five models: infinite, classical, transient, subtransient and general. Saturation curves for both, d-axis and q-axis
  • Automatic calculation of eigenvalues, eigenvectors, mode shapes, participation factors for eigenvalues and state variables
  • Text results: results are presented in clear form and can be customized by several output options
  • Graphical results: results can be visualized by the fully integrated graphical results manager. Charts can be easily printed and exported to external programs (e.g. Microsoft Word) by clipboard functions. A variety of chart options is available
  • The only requirement is the NEPLAN Load Flow module. However, the Small Signal Stability and the Transient Stability (Dynamic Simulation) module of NEPLAN complement each other ideally
  • The Small Signal Stability module is completely integrated in NEPLAN and uses standard dynamic element data.


  • Analysis of interarea oscillations
  •  Analysis of interplant oscillations
  •  Analysis of subsynchronous oscillations/resonance (SSR)
  • Identification of groups and subgroups of machines swinging against each other
  • Determination and improvement of power oscillation damping
  • Design and placement of control equipment, such as Power System Stabilizers (PSS)
  • PSS tuning