Engee documentation

Universal Motor

Universal (or serial) motor with electrical characteristics and torque characteristics.

blockType: AcausalElectricPowerSystems.Electromechanical.Brushed.UniversalMotor

universal motor

Path in the library:

/Physical Modeling/Electrical/Electromechanical/Brushed Motors/Universal Motor

Description

Block Universal Motor simulates the electrical characteristics and torque of a universal (or serial) motor using the following equivalent circuit:

universal motor 1

In this diagram

  • — armature winding resistance;

  • — inductance of the armature winding;

  • — resistance of the excitation winding;

  • — inductance of the excitation winding.

If the Model parameterization parameter is set to By equivalent circuit parameters, then the parameters of the equivalent circuit for this model are given. Block Universal Motor calculates the torque of the motor as follows:

  • The magnetic field in the motor induces the following back EMF in the armature winding:

    Where — the constant of proportionality, and — angular velocity.

  • The mechanical power is equal to the power caused by the back EMF:

  • Engine torque:

The dependence of torque on speed for the universal engine model is related to the parameters in the above diagram. If the Model parameterization parameter is set to By DC rated power, rated speed & maximum torque or By DC rated power, rated speed & electrical power, then the parameters of the equivalent circuit are calculated as follows:

  • Parameter does not affect the dependence of torque on speed in steady-state mode when using a DC source.

  • The voltages in the circuit are summed up:

  • Solve the previous equation for and substitute this value into the equation for torque:

    The unit uses the rated speed and power to calculate the rated torque. The unit uses the values of the rated torque and rated speed in the previous equation plus the corresponding electrical power to determine the values and .

If the Model parameterization parameter is set to By AC rated power, rated speed, current & electrical power, then inductive terms should be included in the model and . This requires information about the RMS rated current and voltage for the total inductance.

The block simulates the inertia of the engine and damping for all values of the Model parameterization parameter. The output torque is:

The unit creates a positive torque acting from the mechanical ports C to R.

Thermal effects of the model

Thermal ports can be opened to simulate the effects of losses in the conversion of energy into heat. To open thermal ports, select the check box for the Enable thermal port parameter.

Ports

Conserving

# + — positive terminal
electricity

Details

A non-directional port connected to the positive terminal of the universal motor.

Program usage name

p

# – — negative terminal
electricity

Details

A non-directional port connected to the negative terminal of the universal motor.

Program usage name

n

# R — engine rotor
rotational mechanics

Details

A mechanical non-directional port connected to the rotor of a universal motor.

Program usage name

rod_flange

# C — engine housing
rotational mechanics

Details

A mechanical non-directional port connected to the universal motor housing.

Program usage name

case_flange

# Hf — thermal port of the excitation winding
warm

Details

Thermal port of the excitation winding.

Dependencies

To use this port, select the Enable thermal port checkbox.

Program usage name

field_thermal_port

# Ha — thermal port of the armature winding
warm

Details

The thermal port of the armature winding.

Dependencies

To use this port, select the Enable thermal port checkbox.

Program usage name

armature_thermal_port

Parameters

Electrical Torque

# Model parameterization — parameterization of the block
By equivalent circuit parameters | By DC rated power, rated speed & maximum torque | By DC rated power, rated speed & electrical power | By AC rated power, rated speed, current & electrical power

Details

Select one of the following block parameterization methods:

  • By equivalent circuit parameters — set the electrical parameters for the equivalent motor circuit model.

  • By DC rated power, rated speed & maximum torque — set DC power values and speed parameters, which the unit converts into an equivalent motor circuit model.

  • By DC rated power, rated speed & electrical power — set the values of AC power and speed parameters, which the unit converts into an equivalent motor circuit model.

  • By AC rated power, rated speed, current & electrical power — set the values of AC power and speed parameters, which the unit converts into an equivalent motor circuit model.

Values

By equivalent circuit parameters | By DC rated power, rated speed & maximum torque | By DC rated power, rated speed & electrical power | By AC rated power, rated speed, current & electrical power
Default value

By DC rated power, rated speed & electrical power
Program usage name

parameterization
Evaluatable

No

# Total armature and field winding resistance — the total resistance of the armature winding and the excitation winding
Ohm | mOhm | kOhm | MOhm | GOhm

Details

The total resistance of the armature winding and the excitation winding.

Dependencies

To use this parameter, set the Model parameterization parameter to By equivalent circuit parameters.

Units

Ohm | mOhm | kOhm | MOhm | GOhm
Default value

132.8 Ohm
Program usage name

R_total
Evaluatable

Yes

# Back-emf constant — the anti-EMF ratio
V/(A*rad/s)

Details

The ratio of the voltage generated by the motor to the rotational speed of the motor.

Dependencies

To use this parameter, set the Model parameterization parameter to By equivalent circuit parameters.

Units

V/(A*rad/s)
Default value

0.1722 V/(A*rad/s)
Program usage name

emf_constant
Evaluatable

Yes

# Rated speed (at rated load) — nominal rotation speed
rad/s | deg/s | rad/min | deg/min | rpm | rps

Details

Engine rotation speed at rated mechanical power.

Dependencies

To use this parameter, set the Model parameterization parameter to By DC rated power, rated speed & maximum torque, By DC rated power, rated speed & electrical power or By AC rated power, rated speed, current & electrical power.

Units

rad/s | deg/s | rad/min | deg/min | rpm | rps
Default value

6500.0 rpm
Program usage name

rated_angular_velocity
Evaluatable

Yes

# Rated load (mechanical power) — Rated load
W | uW | mW | kW | MW | GW | V*A | HP_DIN

Details

The mechanical load that the engine is designed for at the rated rotational speed.

Dependencies

To use this parameter, set the Model parameterization parameter to By DC rated power, rated speed & maximum torque, By DC rated power, rated speed & electrical power or By AC rated power, rated speed, current & electrical power.

Units

W | uW | mW | kW | MW | GW | V*A | HP_DIN
Default value

75.0 W
Program usage name

P_m_rated
Evaluatable

Yes

# Rated DC supply voltage — Rated DC power supply voltage
V | uV | mV | kV | MV

Details

The voltage for which the rated power is set.

Dependencies

To use this parameter, set the Model parameterization parameter to By DC rated power, rated speed & maximum torque or By DC rated power, rated speed & electrical power.

Units

V | uV | mV | kV | MV
Default value

200.0 V
Program usage name

V_DC_rated
Evaluatable

Yes

# Maximum (starting) torque — maximum torque
N*m | uN*m | mN*m | kN*m | MN*m | GN*m | kgf*m | lbf*in | lbf*ft

Details

The maximum torque generated by the engine.

Dependencies

To use this parameter, set the Model parameterization parameter to By DC rated power, rated speed & maximum torque.

Units

N*m | uN*m | mN*m | kN*m | MN*m | GN*m | kgf*m | lbf*in | lbf*ft
Default value

0.39 N*m
Program usage name

max_torque
Evaluatable

Yes

# Electrical power in at rated load — electrical power at rated mechanical power
W | uW | mW | kW | MW | GW | V*A | HP_DIN

Details

The amount of electrical power consumed by the motor at rated mechanical power.

Dependencies

To use this parameter, set the Model parameterization parameter to By DC rated power, rated speed & electrical power or By AC rated power, rated speed, current & electrical power.

Units

W | uW | mW | kW | MW | GW | V*A | HP_DIN
Default value

160.0 W
Program usage name

P_e_rated
Evaluatable

Yes

# RMS rated voltage — RMS rated voltage
V | uV | mV | kV | MV

Details

RMS power supply voltage when the motor is powered by AC.

Dependencies

To use this parameter, set the Model parameterization parameter to By AC rated power, rated speed, current & electrical power.

Units

V | uV | mV | kV | MV
Default value

240.0 V
Program usage name

V_AC_rated
Evaluatable

Yes

# RMS current at rated load — RMS current at rated load
A | pA | nA | uA | mA | kA | MA

Details

RMS current when the motor is powered by AC at rated load.

Dependencies

To use this parameter, set the Model parameterization parameter to By AC rated power, rated speed, current & electrical power.

Units

A | pA | nA | uA | mA | kA | MA
Default value

0.8 A
Program usage name

I_AC_rated
Evaluatable

Yes

# AC frequency — frequency of alternating current
Hz | kHz | MHz | GHz

Details

The frequency of the AC power supply.

Dependencies

To use this parameter, set the Model parameterization parameter to By AC rated power, rated speed, current & electrical power.

Units

Hz | kHz | MHz | GHz
Default value

50.0 Hz
Program usage name

f
Evaluatable

Yes

# Total armature and field winding inductance — the total inductance of the armature winding and the excitation winding
H | nH | uH | mH

Details

The total inductance of the armature winding and the excitation winding. If the value of this inductance is not known, then set a small non-zero number.

Note

You can set the value of Total armature and field winding induction to zero, but this only makes sense if the motor is controlled using a DC power source.

Dependencies

To use this parameter, set the Model parameterization parameter to By equivalent circuit parameters, By DC rated power, rated speed & maximum torque or By DC rated power, rated speed & electrical power.

Units

H | nH | uH | mH
Default value

0.525 H
Program usage name

L_total
Evaluatable

Yes

Mechanical

# Rotor inertia — inertia of the rotor
kg*m^2 | g*m^2 | kg*cm^2 | g*cm^2 | lbm*in^2 | lbm*ft^2 | slug*in^2 | slug*ft^2

Details

The resistance of the rotor to a change in the rotation speed of the motor. The value can be zero.

Units

kg*m^2 | g*m^2 | kg*cm^2 | g*cm^2 | lbm*in^2 | lbm*ft^2 | slug*in^2 | slug*ft^2
Default value

2e-4 kg*m^2
Program usage name

J
Evaluatable

Yes

# Rotor damping — dissipated rotor energy
N*m*s/rad | mN*m*s/rad | kN*m*s/rad | kgf*m*s/rad | lbf*ft*s/rad

Details

The energy dissipated by the rotor. The value can be zero.

Units

N*m*s/rad | mN*m*s/rad | kN*m*s/rad | kgf*m*s/rad | lbf*ft*s/rad
Default value

1e-6 N*m*s/rad
Program usage name

damping
Evaluatable

Yes

# Initial rotor speed — initial rotation speed
rad/s | deg/s | rad/min | deg/min | rpm | rps

Details

The rotation speed of the rotor at the beginning of the simulation.

Units

rad/s | deg/s | rad/min | deg/min | rpm | rps
Default value

0.0 rpm
Program usage name

angular_velocity_start
Evaluatable

Yes

Temperature Dependence

# Field to armature resistance ratio, Rf/Ra — the ratio of the resistances of the excitation winding and the armature winding

Details

The ratio of the resistances of the excitation winding and the armature winding. This parameter is required only when using the thermal ports of the armature and excitation windings. It is used to determine the individual resistance values for the field and armature windings in order to properly distribute the heat generated by the two resistors.

Dependencies

To use this option, select the Enable thermal port checkbox.

Default value

1.0
Program usage name

resistance_ratio
Evaluatable

Yes

# Resistance temperature coefficients, [alpha_f, alpha_a] — temperature coefficients of armature and rotor resistance
1/K | 1/degR | 1/deltaK | 1/deltadegC | 1/deltadegF | 1/deltadegR

Details

A vector is a 1 by 2 row containing the coefficients in the equation relating resistance to temperature. The first element corresponds to the excitation winding, and the second element corresponds to the armature winding. The default values are for copper.

Dependencies

To use this option, select the Enable thermal port checkbox.

Units

1/K | 1/degR | 1/deltaK | 1/deltadegC | 1/deltadegF | 1/deltadegR
Default value

[3.93e-3, 3.93e-3] 1/K
Program usage name

alpha_vector
Evaluatable

Yes

# Measurement temperature — Measurement temperature
K | degC | degF | degR | deltaK | deltadegC | deltadegF | deltadegR

Details

The temperature for which the engine parameters are determined.

Dependencies

To use this option, select the Enable thermal port checkbox.

Units

K | degC | degF | degR | deltaK | deltadegC | deltadegF | deltadegR
Default value

25.0 degC
Program usage name

T_measurement
Evaluatable

Yes

Thermal Port

# Enable thermal port — switching on thermal ports

Details

Modeling of thermal effects.

To enable the simulation of thermal effects, set the option checkbox to enabled.

Default value

false (switched off)
Program usage name

has_thermal_port
Evaluatable

No

# Thermal masses, [Mf, Ma] — thermal masses
J/K | kJ/K

Details

The vector is a 1 by 2 row containing the values of the thermal mass for the excitation windings and the armature.

Thermal mass is the energy required to raise the temperature by one degree.

Dependencies

To use this option, select the Enable thermal port checkbox.

Units

J/K | kJ/K
Default value

[100.0, 100.0] J/K
Program usage name

thermal_mass_vector
Evaluatable

Yes

# Initial temperatures, [T_field, T_armature] — initial temperatures
K | degC | degF | degR | deltaK | deltadegC | deltadegF | deltadegR

Details

The vector is a 1 by 2 row containing the temperature values of the thermal excitation ports and the armature at the beginning of the simulation.

Dependencies

To use this option, select the Enable thermal port checkbox.

Units

K | degC | degF | degR | deltaK | deltadegC | deltadegF | deltadegR
Default value

[25.0, 25.0] degC
Program usage name

T_vector_start
Evaluatable

Yes

Literature

Bolton, W. _Mechatronics: Electronic Control Systems in Mechanical Engineering and Electrical Engineering, 3rd Edition Pearson Education, 2004.