Ipsa 2 Transient Stability

IntroductionThe optional Transient Stability module enables users to analyse the dynamic response of an electrical power system to faults and switchingoperations. Ensuing study results determine critical clearing times, fault ride through compliance, motor starting and re-acceleration as well asgovernor and AVR response and tuning.

Dynamic controllers, such as governors and AVRs are modelled using theuser-defined modelling (UDM) block diagram editor. Network controllersare modelled to represent distributed control systems and smart gridcontrollers. Custom ‘black box’ models can be developed for complexcontrollers.

Transient Stability is available to Ipsa 2 clients as an optionalmodule to determine power system response characteristics. Themodule supports any preferred combination of simulation, outputand modelling criteria, as specified by the user.

This powerful module includes custom ‘black box’ controllers,protection relay operation and has empirical validation.

Load Flow

Fault Level

Transient Stability

Protection Grading

Harmonics

Reliability

Scripting

DC Networks

Training & Support

The simulation, analysis, display and modelling options include:

Simulation Options• Intelligent time step control for fast simulations

• All power system variables are plotted including internalcontroller signals

• UDM controllers are automatically reloaded after editing

• Individual switching times are featured within the equipmentproperties menu

• Protection relays operating during transient simulations

Results Output Options• Directly plot results on up to eight in-built graphs for

interactive, flexible analysis

• Each plot is configurable to display specific system parametersof busbars or connected equipment

• Store output results as files for easy future access

• View and save results as reports for summative analysis

Fault ride through analysis Critical clearing time studies

Branch and Transformers• Time dependent switching operations

• Protection relay operations

• Circuit breaker intertrip operations

Network Controllers• Network controllers denote devices such as SCADA and

smart grid controllers that manage multiple networkcomponents

• Implemented using plug-in controllers with inputs andoutputs configured to link to any network component

User-Defined Models (UDM)• Block diagram illustration for synchronous and induction

machine controllers

• Library of user-editable governor and IEEE AVR models

• New models are developed for all types of controllersincluding governors and AVRs

• UDM model changes are immediately reflected in thetransient stability simulations with no need to compileor link

Plug-in Models• Used to represent specialised controllers, for example,

wind turbine or SCADA controllers

• Written in C++ and optionally Fortran languages

• Provided as a ‘black box’ to the end user

• Parameter entry is through an automatically generateddialogue during network set up

Ipsa 2 Transient Stability

TNEI Bainbridge House 86-90 London Road Manchester M1 2PW

+44 (0) 161 233 4800 software@ipsa-power.com www.ipsa-power.com

Ipsa Power is developed, maintained and supported by TNEI

Transient Models

Synchronous Machines• Full D-Q axis, sub-transient, transient and synchronous

representation with saliency and saturation effects

• Standard AVRs and governors provided

• Custom AVR and governor models using UDM or plug-in controllers

• Multi-mass shafts with standard, UDM or plug-in controllers

Induction Machines• Single and double cage models

• Inner-outer or running – standstill impedances

• Polynomial representation of mechanical torque

• UDM or plug-in modelling for multi-mass shafts or complextorque/speed characteristics

• Under-voltage and under-speed drop-out relays with lock outtimes

• Default DFIG rotor converter power control

• Default rotor converter over-current protection

Universal Machines• For modelling complex and specialised controllers such as wind

turbines

• Transient response specified as UDM or plug-in controllers

• Current injection on system or DQ axis reference frame

Wind Turbine and PV Modelling• Wind turbines modelled using induction, DFIG, synchronous or full

converter generators

• Dynamic controls provided by built in, UDM or plug-in controllers

• Manufacturer plug-in controllers available for Gamesa, Siemens,Nordex, Enercon and other external suppliers

• Implementation of PV controllers

Switched Devices• Switched capacitors and reactor controllers are represented using

plug-in controller models

DC Systems• Line commutated and PWM converter built in models

• Separate AC and DC side controllers using UDM or plug-ins

• DC machines and motor generator sets with controllers

• Battery models with internal inductance

User interface