PLECS 1.3 Online Help

DC Machine

Purpose

Simple model of DC machine.

Library

Machines

Description

[Picture]

The machine operates as a motor or generator; the sign of the mechanical torque determines the mode of operation (positive for motoring, negative for generating). In the component icon, the positive poles of armature and field winding are marked with dots.

Electrical System

pict

Electromagnetic torque:

Te = Laf  if   ia

Induced voltage of the armature winding:

Ea = Laf  if   !m

Mechanical System

!m  =  1(Te   F !m    Tm)
       J

Parameters and Dialog Box

[Picture]

Armature resistance
Armature winding resistance Ra in ohms (_O_).
Armature inductance
Armature winding inductance La in henries (H).
Field resistance
Field winding resistance Rf in ohms (_O_).
Armature inductance
Field winding inductance Lf in henries (H).
Field-armature mutual inductance
Field-armature mutual inductance Laf in henries (H).
Inertia
Combined rotor and load inertia J in Nms2.
Friction coefficient
Viscous friction F in Nms.
Number of pole pairs
Number of pole pairs p.
Initial rotor speed
Initial mechanical speed !m;0 in radians per second (s1).
Initial armature currents
Initial current ia;0 in the armature winding in amperes (A).
Initial field current
Initial current if;0 in the field winding in amperes (A).

Inputs and Outputs

Mechanical torque
The input signal Tm represents the mechanical torque at the rotor shaft, in Nm.

The output vector "m" contains the following 2 signals:

(1) Rotor speed
The rotational speed !m of the rotor in radians per second (s1).
(2) Electrical torque
The electrical torque Te of the machine in Nm.