: Public Class
Created: 05/03/2009 08:14:39 AM
Modified: 06/24/2012 03:35:28 PM
Project:
Advanced:
Aggregate induction motor load. This model  is used to represent a fraction of an ordinary load as "induction motor load".  It allows load that is treated as ordinary constant power in power flow analysis to be represented by an induction motor in dynamic simulation.  If <b>Lpp</b> = 0. or <b>Lpp</b> = <b>Lp</b>, or <b>Tppo</b> = 0.,  only one cage is represented. Magnetic saturation is not modeled. Either a "one-cage" or "two-cage" model of the induction machine can be modeled. Magnetic saturation is not modeled.<br /></p><p><br /></p><p>This model is intended for representation of aggregations of many motors dispersed through a load represented at a high voltage bus but where there is no information on the characteristics of individual motors.<br /></p><p><br /></p><p>This model treats a fraction of the constant power part of a load as a motor. During initialization, the initial power drawn by the motor is set equal to <b>Pfrac</b> times the constant <b>P</b> part of the static load.  The remainder of the load is left as static load.<br /></p><p><br /></p><p>The reactive power demand of the motor is calculated during initialization as a function of voltage at the load bus. This reactive power demand may be less than or greater than the constant <b>Q</b> component of the load.  If the motor's reactive demand is greater than the constant <b>Q</b> component of the load, the model inserts a shunt capacitor at the terminal of the motor to bring its reactive demand down to equal the constant <b>Q</b> reactive load.  <br /></p><p><br /></p><p>If a motor model and a static load model are both present for a load, the motor <b>Pfrac</b> is assumed to be subtracted from the power flow constant <b>P</b> load before the static load model is applied.  The remainder of the load, if any, is then represented by the static load model.<br /></p>
Attribute
Public <a href="../../../EA1/EA52.htm">Float</a>
  d

Details:
GUIDBasedOn={E924980F-8F48-4fbd-A0F0-F1D6AFD10A3D}
Notes: Damping factor (D).  Dimension = delta P/delta speed.
Public <a href="../../../EA1/EA71.htm">Seconds</a>
  h

Details:
GUIDBasedOn={F0FD1C52-0775-434a-9500-FB4301BC7E34}
Notes: Inertia constant (H) (not=0).
Public <a href="../../../EA1/EA52.htm">Float</a>
  lfac

Details:
GUIDBasedOn={7B55D1AF-F5B6-4c9b-85AC-44A71019BDCD}
Notes: Loading factor – ratio of initial P to motor MVA base (Lfac).
Public <a href="../../../EA1/EA66.htm">PU</a>
  lp

Details:
GUIDBasedOn={CFCCAC01-5A98-46bd-8114-530A5D13C6B1}
Notes: Transient reactance (Lp).
Public <a href="../../../EA1/EA66.htm">PU</a>
  lpp

Details:
GUIDBasedOn={B75DCE7C-EE1B-4f60-909D-64CD5F999CFD}
Notes: Sub-transient reactance (Lpp).
Public <a href="../../../EA1/EA66.htm">PU</a>
  ls

Details:
GUIDBasedOn={A7D4FF09-5F6C-4cf3-8D09-A1ECC0B90A8B}
Notes: Synchronous reactance (Ls).
Public <a href="../../../EA1/EA52.htm">Float</a>
  pfrac

Details:
GUIDBasedOn={1D8468A9-BB75-439b-9CDD-031979BEDDAD}
Notes: Fraction of constant-power load to be represented by this motor model (Pfrac) (>=0.0 and <=1.0).
Public <a href="../../../EA1/EA66.htm">PU</a>
  ra

Details:
GUIDBasedOn={2EBF719B-7221-43f6-89D0-2262283F223F}
Notes: Stator resistance (Ra).
Public <a href="../../../EA1/EA71.htm">Seconds</a>
  tbkr

Details:
GUIDBasedOn={F3B08BB9-8193-4eb0-B62C-DFBB9AC72F0E}
Notes: Circuit breaker operating time (Tbkr) (default=999).
Public <a href="../../../EA1/EA71.htm">Seconds</a>
  tpo

Details:
GUIDBasedOn={31ACC981-C4AC-45bd-8CA1-01B3F8B3B1BA}
Notes: Transient rotor time constant (Tpo) (not=0).
Public <a href="../../../EA1/EA71.htm">Seconds</a>
  tppo

Details:
GUIDBasedOn={FFCCD719-96F8-4d29-88AE-7AC5107217C7}
Notes: Sub-transient rotor time constant (Tppo).
Public <a href="../../../EA1/EA71.htm">Seconds</a>
  tv

Details:
GUIDBasedOn={8D2E6339-44AA-470f-9644-7978BEDD30BD}
Notes: Voltage trip pickup time (Tv) (default=999).
Public <a href="../../../EA1/EA66.htm">PU</a>
  vt

Details:
GUIDBasedOn={8DB2CEC8-F4C3-486a-82BD-040623B3666F}
Notes: Voltage threshold for tripping (Vt) (default=0).
Element Source Role Target Role
LoadAggregate1
Class  
Name: LoadMotor
Aggregate motor (dynamic) load associated with this aggregate load.
Name: LoadAggregate
Aggregate load to which this aggregate motor (dynamic) load belongs.
Details:
 
Tag Value
GUIDBasedOn {26A10608-6EE9-42d6-8969-6212CD99C9E0}
Details:
 
Object Type Connection Notes
IdentifiedObject Class Generalization