This module is a robust and easy to use tool for assessing system voltage dips and acceleration times of motors, using a variety of starting methods.
The selection of the motor to be started along with the starting method is defined in a grid-style study dialog box. The study dialog box also gives the user the option to change the status of any motor in the network. This includes the switching of motors either to off, running, locked rotor or starting.
Induction Motor Starting
Induction Motor Starting analysis takes into account the inertial effects of the motor, user-defined load curves and supports several starting methods as listed below:
The above motor starting assistance methods are also supported in our Transient Stability module.
Synchronous Motor Starting
Synchronous Motor Starting analysis takes into account the inertial effects of the motor, user-defined load curves and excitation system parameters to synchronize the motor when the speed approaches synchronous speed. The algorithm takes into account the pulsating behavior of a starting synchronous motor due to the nature of the winding connections.
The program supports several starting methods:
A detailed user-defined load torque representation is provided with the program along with the opportunity to plot the nominal electrical and mechanical torque curves prior to starting the motor.
The load torque data can be entered from manufacturer data curves or with the general equation of load torque versus speed. In addition, default load curve characteristics of typical mechanical loads such as pumps, blowers, fans, feed drive and conveyer belts are also included.
In the absence of detailed information, the module includes support functions for deducing the equivalent circuit parameters for single circuit rotor, double circuit rotor or deep bar circuit rotor induction motors, utilizing any the following information:
This module also supports the estimation of synchronous motor electrical parameters from physical quantities.
Locked Rotor Analysis
Locked Rotor Analysis (LRA) calculates the voltage dip of induction and synchronous starting motors on the network.
This includes the voltage dip color coding of the one-line diagram and analysis reports taking into account the number of starts per day as defined in the flicker table.
Across the line, resistor and/or inductor, capacitor, auto transformer, star/delta and variable frequency starters are supported.
Maximum Start Size Analysis
Maximum Start Size analysis is used to estimate the maximum motor size that can be started on a given bus or section of the network given the allowable voltage drop.