Transient Stability

Transient Stability Analysis

Transient stability analysis enables engineers to accurately simulate and analyze power system dynamics and transients via system disturbances and other events. ETAP Transient Stability leverages detailed and validated equipment, protection functions, and built-in and graphical user defined control models to perform analysis for industrial to transmission power systems.

Applications

Calculate Critical Fault Clearing Time (CFCT) & Critical Separation Time (CST)
Short & long-term transient simulations
Confirm generator rotor angle stability
Evaluate motor dynamic acceleration & reacceleration impact upon power restoration (brown-out)
Identification and testing load shedding (optimal as well as traditional relay based)
Computing and testing fast load transferring via fast bus transfers
Calibrate and evaluate relay settings
Generator start-up or black-start simulation (add-on module)
Simulate and analyze microgrids in grid-connected, islanded and transition modes
Transformer Inrush Analysis
Grid Code Compliance & Analysis (add-on module)
Electromagnetic transient simulation (eMTCoSim™) (add-on module)

Analytical Capabilities

Simulate loss of excitation
Generator start-up
Generator frequency action 
Tie CB closing with auto synch-check action
Utility new voltage actions for Voltage Ride Through – LVRT & HVRT 
Induction and synchronous motor acceleration
Motor Operated Valve (MOV) starting
Motor load impact & ramp change
Handle multiple subsystems and islanded systems
Automatic relay actions based on relay settings & system response
Frequency estimation method, with voltage blocking for frequency relay action
Embedded conventional and adaptive Newton-Raphson initial load flow methods
eMTCoSim™ - Phasor & EMT CoSimulation (add-on module)

Modeling Capabilities

Complete synchronous & induction machine models
Comprehensive excitation system & turbine/engine-governor models
Static var compensator (SVC) model
High voltage direct current transmission (HVDC) model
Standard Power System Stabilizer (PSS) models
Frequency dependent modeling for synchronous machines (sub-transient models) and induction machines
Voltage Source Converter / Inverter model
Renewable and energy storage resource models
Voltage, current, frequency, power and synch check protective relays
Electrical Transient Stability Dynamic Modeling

Software Capabilities

Unlimited sequence of events & actions
User-controlled simulation parameters
Set & adjust exciter, AVR, turbine-governor or engine parameters
Fault impedance for Bus and Branch faults 
Integrated with User-Defined Dynamic Models (UDM) Program
Inverter charging/discharging state
Variable total simulation time & simulation step
Faster calculation time by skipping tabular plots
Electrical Transient Stability Reporting
Plot useful quantities for various equipment (Plot View)
Graphically compare results of different study reports (Plot Analyzer)
Live Plot of analysis results within One-line diagram and Plot View

Disturbance and Events

3-phase & Line-Line, Line-Ground & Line-Line-Ground fault actions
Branch segment fault
Protective device open and close
Generator
- Power set-point adjustment
- Voltage set-point adjustment
- Isochronous / droop mode changes
- Field winding fault
- Loss of excitation
- Start
Power Grid
- Voltage drop impact and rise/swell
- Frequency change
Motor
- Acceleration/reacceleration
- Acceleration using conventional starters
- Acceleration using conventional soft-starters
- Acceleration using conventional VFD
- Load adjustment
WTG
- Wind gust
- Wind ramp
- User-defined wind disturbance
Load step ad ramp power change
Motor Operated Valve (MOV) start
Variable Frequency Drive (VFD) frequency change