DSATools™ Core Module | TSAT TSAT Transient Security Assessment Tool

TSAT provides analysis functions and modeling capabilities for the following applications:

• Transient stability analysis for large power grids with compliancy to NERC standards
• Transfer limit determination
• On-line transient security assessment
• IPP integration studies
• Analysis of renewable energy sources
• Cascading outage analysis
• Control design and tuning (with SSAT)
• Small signal stability studies (with SSAT)
• Voltage stability studies (with VSAT)
• Frequency stability analysis
• Design of special protection systems (SPS)
• Verification of device model and performance
• System restoration and black-start analysis
• Construction of system responses in post-mortem incident analysis
• Generation of simulated PMU signals (with ePMU)
• Other

• Powerful off-line analysis capabilities
• Readily configured with EMS for on-line use
• Selection of various security compliant with NERC standards
• Comprehensive modeling support
• Extensive contingency analysis features
• Stability-constrained transfer limit determination
• Case setup, model/data verification, and output analysis tools
• Scalable distributed computation engine
• Available add-on modules with extended application capabilities
• Possibility for hybrid simulations with an electromagnetic transient simulation engine

• Transient stability: a transient stability index is provided with a choice of computation algorithms.
• Damping: the minimum damping of the dominant rotor angle oscillation in the system is computed.
• Transient voltage: violations are captured with custom under-voltage and over-voltage criteria.
• Transient Frequency: violations can be identified for a specified lower/upper range and rate of change limit.
• Relay margin: margins to relay operation on all monitored lines are computed.
• Application of security criteria is customizable for different regions of the system and contingencies.
• Alternative numerical integration methods are available.
• All contingencies can be ranked using any of the indices for scanning of large number of contingencies.

• Fully customized contingencies can be easily created with the user interface provided.
• For compliancy studies (such as NERC TPL), contingencies can be created by pre-set rules or by the add-on module Contingency Creator.
• Simulations can be early terminated to achieve fast computation speed.
• A wide selection of events can be simulated:
  • Faults of various types (three phase, single phase, two-phase-to-ground) at bus or on a branch
  • Branch (single, two, or three phase) tripping and reconnection, shunt switching, adding or modifying branch
  • Generator tripping, exciter or governor reference setpoint changes
  • Load shedding, load ramping, motor starting
  • Breaker-based switching operations
  • Pre-simulation outages and powerflow dispatches
  • Dependent contingencies

TSAT can help determine stability limits in a system:

• Very flexible power transfer definition (one- or two-dimension), based on the source-sink concept.
• Different stability limit search strategies, including manual, binary, and fully automatic.
• Forward and backward limit searches.
• Built-in powerflow dispatcher and solver.

• Determination of the maximum transfer capability on an interface, based on any or a combination of all available security criteria.
• Limit determination philosophy consistent with the similar functions in VSAT and SSAT; thus results are comparable.

TSAT supports a comprehensive model library, including the following conventional models:

• Generator: from classical to two-axis 6th order models.
• Excitation system: all IEEE standard exciter/AVR and PSS models and common extended models.
• Speed governing system: all IEEE standard models and common extended models.
• Relay: under-voltage/frequency load shedding, switchable shunts, distance relay.
• Load: ZIP model, voltage/frequency dependent model, induction motor, and composite load model.

Among the advanced modeling capabilities, TSAT supports:

• User-defined modeling: function block and connectivity-based UDM approach with capability to interface with user-written control blocks.
• Renewable energy source models: wind turbines, photovoltaic plants, storage devices, etc.
• FACTS model library: SVC/SVS, TCBR, STATCOM, TCSC, SSSC, TCMCT, TCPST.
• HVDC model library: two- and multi-terminal HVDC models (LCC and VSC), DC grid modeling, converter-based FACTS models.

• Extended term simulation model library: OEL, ULTC. Special Protection System (SPS) models.

TSAT supports network and data in the node/breaker format.

A wide selection of system quantities can be monitored during simulations, including:

• Generator: angle, speed, voltage, mechanical and electrical power, field voltage, etc.
• Bus: voltage, angle, frequency.
• Branch: power, current, apparent impedance.
• Load: power, voltage.
• Other: generator state variables, motor/FACTS/HVDC quantities, UDM block outputs, branch interface quantities, regional quantities, etc.

Quantities to be monitored can be customized, and system monitoring can be specified using a number of options.

• Connection to PSAT for examining, modifying, and solving powerflow.
• Connection to UDM Editor for creating, examining, and modifying user-defined models.
• Different levels of details for examining base case and transfer analysis results.
• Comprehensive output analysis module (DSAOA) that creates various types of plots and output reports.
• DSAOA plotting module for extensive studies of simulations, with flexible plotting options:
  • Highly customizable x-t and x-y plots.
  • Batch plotting capability based on scripting language.
  • Data and graphics importing/ exporting facilities (ASCII text, MS Office, and Postscript).
  • Study tools such as relay analysis, case comparison, curve statistics, and detailed Prony analysis.

• Capability to integrate, through the DSA Manager™ module, with EMS for on-line dynamic security assessment.
• Generation of simulated PMU signals in IEEE C37.118 format from near real-time simulations with the add-on module ePMU.
• Creation of the complete contingency set automatically according to NERC TPL standard with the add-on module Contingency Creator.
• Possibility of performing hybrid simulations with an electromagnetic transient simulation engine (such as RTDS).
• Power system components can be identified using bus numbers, bus names, or equipment names.
• Model and data verification tools:
  • Exciter/governor/renewable generator step response simulations.
  • No disturbance test simulation.
  • Injection of bus V magnitude/frequency curves (“playback simulations”).
• Case archive feature to store or share study cases.
• Snapshot feature to pack a simulation for later continuation of the simulation. 
• Data conversion tool to import powerflow and contingency data in third-party formats including PSS/E, PSLF, BPA, etc.
• Distributed computation to enable simultaneous simulations of multi-contingency/ scenario cases on multiple servers, or multiple CPU cores.
• Analysis of power systems of up to 100,000 buses and 15,000 generators.
• Runs on MS Windows 7/10/server 2012 R2/server 2016