WOLFRAM SYSTEM MODELER

DCPM_Cooling

Test example: Cooling of a DCPM motor

Diagram

Wolfram Language

In[1]:=
SystemModel["Modelica.Electrical.Machines.Examples.DCMachines.DCPM_Cooling"]
Out[1]:=

Information

This information is part of the Modelica Standard Library maintained by the Modelica Association.

Test example: Demonstrate cooling of a DCPM motor
The motor starts at no-load speed, then load pulses are applied.
The cooling circuit consists of armature's thermal capacitance, a thermal conductance between armature and core, core's thermal capacitance and a thermal conductance between core and coolant. The coolant flow circuit consists of inlet, volume flow, a pipe connected to the core and the outlet.
Please note:
  • All unused heat ports of the thermal port (i.e., without loss sources in the machine: brush, stray, friction, permanent magnet) have to be connected to a constant temperature source.
  • The thermal capacitances (i.e., time constants) are unusual small to provide short simulation time!
  • The coolant is a theoretical coolant with specific mass = 1 kg/m3 and cp = 1 J/kg.K.
  • The thermal conductances as well as the coolant flow are parametrized such way, that:
  1. the total coolant's temperature rise is 10 K (over coolant inlet)
  2. the core's temperature rise is 27.5 K (over coolant's average temperature between inlet and outlet)
  3. the armature's temperature rise is 55 K (over coolant's average temperature between inlet and outlet)
Simulate for 25 seconds and plot (versus time):
  • armature.T: armature temperature
  • core.T: core temperature
  • cooling.T: coolant temperature at outlet
Therefore the armature temperature would reach nominal armature temperature at constant nominal load.
Default machine parameters are used, but:
  • The armature winding material is set to Copper.
  • Armature reference temperature is set to 80 degC.
  • Nominal armature temperature is set to 80 degC.

Parameters (16)

Va

Value: 100

Type: Voltage (V)

Description: Actual armature voltage

Ve

Value: 100

Type: Voltage (V)

Description: Actual excitation voltage

w0

Value: Modelica.Units.Conversions.from_rpm(1500)

Type: AngularVelocity (rad/s)

Description: No-load speed

TLoad

Value: 63.66

Type: Torque (N⋅m)

Description: Nominal load torque

JLoad

Value: 0.15

Type: Inertia (kg⋅m²)

Description: Load's moment of inertia

TAmbient

Value: 293.15

Type: Temperature (K)

Description: Ambient temperature

Ca

Value: 20

Type: HeatCapacity (J/K)

Description: Armature's heat capacity

Cc

Value: 50

Type: HeatCapacity (J/K)

Description: Core's heat capacity

Losses

Value: dcpm.Ra * dcpm.IaNominal ^ 2

Type: Power (W)

Description: Nominal Losses

T0

Value: 293.15

Type: Temperature (K)

Description: Reference temperature 20 degC

dTCoolant

Value: 10

Type: TemperatureDifference (K)

Description: Coolant's temperature rise

dTArmature

Value: dcpm.TaNominal - T0 - dTCoolant / 2

Type: TemperatureDifference (K)

Description: Armature's temperature rise over coolant

G_armature_core

Value: 2 * Losses / dTArmature

Type: ThermalConductance (W/K)

Description: Heat conductance armature - core

G_core_cooling

Value: 2 * Losses / dTArmature

Type: ThermalConductance (W/K)

Description: Heat conductance core - cooling

CoolantFlow

Value: 50

Type: VolumeFlowRate (m³/s)

Description: Coolant flow

dcpmData

Value:

Type: DcPermanentMagnetData

Description: Common parameters for DC machines

Connectors (1)

thermalPort

Type: ThermalPortDCPM

Description: Thermal port of DC machine with permanent magnets

Components (16)

dcpm

Type: DC_PermanentMagnet

Description: DC machine data

armatureVoltage

Type: ConstantVoltage

Description: Source for constant voltage

groundArmature

Type: Ground

Description: Ground node

loadInertia

Type: Inertia

Description: 1D-rotational component with inertia

loadTorque

Type: Torque

Description: Input signal acting as external torque on a flange

pulse

Type: Pulse

Description: Generate pulse signal of type Real

armature

Type: HeatCapacitor

Description: Lumped thermal element storing heat

armatureCore

Type: ThermalConductor

Description: Lumped thermal element transporting heat without storing it

core

Type: HeatCapacitor

Description: Lumped thermal element storing heat

coreCooling

Type: ThermalConductor

Description: Lumped thermal element transporting heat without storing it

inlet

Type: Ambient

Description: Ambient with constant properties

volumeFlow

Type: VolumeFlow

Description: Enforces constant volume flow

cooling

Type: Pipe

Description: Pipe with optional heat exchange

outlet

Type: Ambient

Description: Ambient with constant properties

fixedTemperature

Type: FixedTemperature

Description: Fixed temperature boundary condition in Kelvin

dcpmData

Type: DcPermanentMagnetData

Description: Common parameters for DC machines