Transient stability analysis

Transient stability analysis

Analytical capabilities

• LLL, L-G, LL and LL-G fault application and removal
• Global setting of control parameters for generators, motors and electronically-coupled generating units
• Line switching and line re-closing
• Single-pole switching, including line charging effects
• Load shedding and load adding
• Generation loss
• Disconnection of lines, cables and transformers
• Tripping and re-closing of protective devices
• Frequency-dependent modelling of generators
• Networks with multiple nominal frequencies
• Ability to monitor specific equipment during the simulation
• Load modelling as a function of voltage and frequency at individual bus bars or throughout the system
• Disconnection of static VAR compensator controls
• Addition and removal of shunts
• Direct on-line or assisted induction motor starting and stopping
• Direct on-line or assisted synchronous motor-starting
• Automatic validation of manoeuvres and their sequencing in time
• Verification of equipment and controller data
• Ability to vary the integration step during the simulation
• Ability to interrupt the simulation temporarily and restart
• Range validation for controller settings and simulation parameters

Control model library

The control model library of Eaton's CYME Transient Stability analysis module is an extensive library of dynamic models of equipment and their controls. This includes default data values of the parameters, their description and block diagrams as per published transactions and papers.

This includes control models of:

• Round pole and salient pole generators
• Modelling of excitation systems taking saturation into account, based on IEEE standards
• Power system stabilisers
• Governor models comprising hydraulic, thermal, diesel and gas turbines
• Detailed modelling of static-VAR compensators
• Under-voltage, under-frequency, frequency droop relays and overcurrent relay modelling
• Impedance relay with typical circular trip characteristics including single reset time re-closing
• Induction motor models with frequency-dependent modelling
• Dynamic modelling of distributed generation such as Wind Energy Conversion Systems (WECS), photovoltaic (PV cells), fuel cells and micro turbines 

User-defined modelling

The Transient Stability analysis module features a unique ability to supplement the existing array of control models for system equipment and controllers, providing the user with the opportunity to model any desired control system using user-defined modelling.

The user-defined modelling approach is based on the premise of solving user-defined equations. The program is provided with an extensive library of elementary functions and building-block controls to model any control scheme, including system-wide operations.

The model can be created with a simple text editor and there is no need to recompile the software to integrate the new model into the library.

The control model library is so flexible in its design that the user can create or import into the library any control model created with the built-in, user-defined modelling functions. This includes any model created previously for the PSAF software or any new one that the user may wish to add to Eaton's CYME software library in order to include it in any study requiring such a model. In addition, the user can import dynamic model block diagrams in bitmap image format.

Dynamic modelling of distributed energy resources (DER)