Transient Motor Starting Features


  • Motor Models

    • Induction double-cage, full sub-transient, flux detail model with saturation

    • Synchronous salient-pole, full sub-transient flux detail model with saturation

    • Induction flux motor model includes option for additional stator flux dynamics

    • Includes modeling of starting and running loads, and auto-transfer of load

    • Synchronous motor includes field application at defined speed

  • Motor Load Models

    • Torque as a function of speed squared or cubed

    • Torque vs. speed as a digitized load model function

  • Detailed Model Library

    • Use our supplied data "as is" to do quick checks for a typical system

    • Add your own model data for your system, and future analysis

    • Organize data in user-specified categories for quick locate and import

    • Data sets: over 40 complete model examples

  • Network Model

    • Uses EasyPower’s network model already defined in your database

    • Performs a constant impedance network analysis

    • Auto-transformer tap operation suppressed

    • Utilities modeled as short circuit impedance sources (infinite inertia - fixed frequency)

    • All static loads modeled as constant impedance

    • Resolves network to update conditions for changes in induction motor vars, based on requirements of machine equations at initialization

    • While in TMS/Dynamic Stability focus, system can be changed via breaker operations (right mouse click on breaker) and power flow initial conditions resolved before a simulation


  • Start any single motor, including automatic changes from starting to running load

  • Start entire group of motors via breaker operation

  • Integrated with Scenario Manager™ for quick simulation of various alternatives

  • Modify automatic double-click controls (simulation length, time of action, etc.) to fit your simulation needs

  • Suppress message log as desired with three categories: initialization, runtime, and protective device action messages

  • Modify simulation time step to suit simulation needs

  • Enable/disable all automatic contactor, protective device, and ATS (automatic transfer switch) actions

  • Specify plot length by number of points

  • Automatically copies results to Windows® clipboard for use in any spreadsheet

Protective Device Functionality

  • Includes protective device actions for all devices already defined in database

  • Adds automatic contactor dropout functionality

  • Adds ATS auto-switching functionality

  • Protective device actions can be easily included or excluded from a simulation with a single option setting

Scripting Engine

  • Define a script to perform any type of simulation action in time

  • Allows open/close of any breaker and transfer of any ATS

  • Includes fault application impedance and duration

  • Includes “Run To” and “Run For” time features

  • Start, trip, and re-close any motor or group of motors

  • Create complete motor-sequencing simulation

  • Perform reduced voltage starts via network changes

One-Line Integration

  • Display of one-line at initial condition upon entry to TMS/Dynamic Stability focus

  • Display of system conditions at end of simulation

  • Display of system conditions at any point, using simulation step feature

  • Graphical symbol morphing to indicated inclusion of stability data


  • Includes up to 10 plots, 5 traces per plot, of model and network items

  • Monitor induction motor: terminal voltage, current, watts, and vars; electrical and load torque; speed; and power angle

  • Monitor synchronous motor: terminal voltage current, watts, and vars; speed; electrical torque; mechanical power; field voltage; angle; power angle; D-Axis current; Q-Axis current; D-Axis sub-transient flux; Q-Axis sub-transient flux

  • Monitor bus: voltage, angle, frequency, and fault current

  • Monitor network branch and shunt device: kW, kVar, amps, voltage

  • Plot definitions use quick and intuitive equipment selection right off the one-line

Detailed Message Log

  • Detailed message log tracks all system behavior at initialization and runtime

  • Initialization messages help you quickly debug an ill-defined system model or data

  • Run-time messages show all script actions and automatic switching actions

Model Data Sheets

  • Model data sheets can be quickly printed from the TMS/Dynamic Stability focus

  • Print a single model, or an entire group of equipment items with quick one-line select

Built-In Automatic Control

  • Automatic detection of numerical instability, allowing quick system reset

  • Automatic internal model sub-integration to minimize numerical instability issues at typical simulation time steps

  • Improved modified Euler integration technique

  • Simulation of stator flux transients (dψ/dt terms) using differential instead of integral technique, eliminating numerical instability issues in the motor’s fast time constant stator equations at normal time steps (half to quarter cycle)

  • Detailed data checking of parameters when entering in the database

  • Automatic detection of invalid or insolvable system power flow when entering TMS/Dynamic Stability focus

Control Interface

  • Easy-to-use dynamics focus toolbar with fewer buttons but more capabilities

  • Select scripts to run simulations directly from a drop-down list in the toolbar

  • Pause any simulation for termination

  • Restart any paused simulation

  • Reset to initial conditions at any time during simulation

  • Enable/disable results on the one-line view just like in power flow focus

Induction Motor Parameter Derivation

  • Induction motor parameter derivation tool that lets you determine detailed flux model parameters using your running and starting conditions, and your machine torque speed curve

  • Automatic minimization technique used to locate best parameters to match your data

  • Gravity points help to pull the derivation towards your desired curve

  • Integrated digitizer with spline curves allows overlay of a quick drawing of torque speed curve over a scanned image of actual data

  • With one mouse click, import the derived data directly into your database

  • Easily copy your derived data into the user library

EasyPower Transient Motor Starting requires PowerFlow™ to operate and PowerProtector™ for all protective device simulations. TMS includes Integrated One-Line, SmartDuty™, SmartBreaker™, Scenario Manager™, MCC and Panel Schedules, and SendCAD

Try Before You Buy

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