Engee documentation

Generic Rotary Actuator

A universal rotary actuator controlled by a constant voltage source or a PWM driver.

blockType: AcausalElectricPowerSystems.Electromechanical.MechatronicActuators.GenericRotary

generic rotary actuator

Path in the library:

/Physical Modeling/Electrical/Electromechanical/Mechatronic Actuators/Generic Rotary Actuator

Description

Block Generic Rotary Actuator implements a model of a universal rotary drive designed for control from a constant voltage source or a PWM driver. Determine the characteristics of the torque-speed in the form of tabular values for powering the motor at rated voltage. This functionality allows you to simulate an engine without resorting to an equivalent circuit.

The architecture of a motor or drive determines how electrical losses depend on torque. For example, in a DC motor, losses are proportional to the square of the current. Since torque is proportional to current, losses are also proportional to mechanical torque. In most engines, electrical losses are proportional to the square of the torque. Block Generic Rotary Actuator calculates this loss value using the provided parameters Motor efficiency (percent) and Speed at which efficiency is measured.

Some engines also have a loss factor that is independent of the torque. An example is a shunt motor in which the field winding consumes direct current regardless of the load. Parameter Torque-independent electrical losses takes this effect into account.

Engine EFFICIENCY is the mechanical power divided by the sum of the mechanical power and both electrical losses. The block assumes that the speed at which the efficiency of the engine is determined is in the motor quadrant and, therefore, is positive.

You can work with the unit in the opposite direction by changing the sign of the applied voltage. For example, the block H-Bridge changes the direction of rotation of the motor if the voltage at the REV port is greater than the Reverse threshold voltage parameter. However, if the block is used in the opposite direction, then specify the data «torque-speed» to work in the forward direction:

  • Positive torques and positive speeds in the motor quadrant;

  • Positive torques and negative speeds in the counterclockwise generation quadrant;

  • Negative torque and positive velocity in the generating quadrant clockwise.

Thermal effects of the model

A thermal port can be opened to simulate the effects of losses during the conversion of energy into heat. To open the thermal port, select the checkbox for the parameter Enable thermal port.

Assumptions and limitations

  • Curve data «torque-speed» They correspond only to the rated voltage, so the unit produces accurate results only at plus or minus rated voltage.

  • In this block, it is necessary to provide torque data for the entire range in which the drive is used. To use the drive in the generation and braking areas, provide additional data outside the normal driving area.

  • The behavior of the model is sensitive to the torque-velocity data. For example, the idle speed is correctly determined and is finite only when the data intersects the speed axis.

  • To manage a block from a block H-Bridge:

    • Do not place any other blocks between the block H-Bridge and a block Generic Rotary Actuator.

    • In the dialog box of the block H-Bridge set the Freewheeling mode parameter to Via one semiconductor switch and one freewheeling diode. Choice Via two freewheeling diodes It does not set the output voltage of the bridge to zero when the input PWM signal is low.

    • In the dialog boxes of the blocks H-Bridge, Generic Rotary Actuator and Controlled PWM Voltage make sure that the value Simulation mode the same for all three blocks.

Variables

Use the parameter group Initial Targets to set the priority and initial target values for the block parameter variables before modeling. For more information, see Configuring physical blocks using target values.

Ports

Conserving

# + — positive terminal
electricity

Details

A non-directional port associated with the positive terminal of the drive.

Program usage name

p

# - — negative terminal
electricity

Details

Non-directional port associated with the negative terminal of the drive.

Program usage name

n

# R — rotor
`rotational mechanics

Details

A mechanical non-directional port associated with a rotor.

Program usage name

rod_flange

# C — hull
`rotational mechanics

Details

A mechanical non-directional port associated with the actuator housing.

Program usage name

case_flange

# H — heat port
heat

Details

Heat port.

Dependencies

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

Program usage name

thermal_port

Parameters

Electrical Torque

# Speed values — vector of velocity values
rad/s | deg/s | rad/min | deg/min | rpm | rps

Details

A vector of velocity values for constructing an interpolation table of the correspondence between the values of torque and speed.

Units

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

[-1500.0, -1000.0, -500.0, 0.0, 500.0, 1000.0, 1500.0, 2000.0, 2500.0, 3000.0] rpm
Program usage name

angular_velocity_vector
Evaluatable

Yes

# Torque values — vector of torque values
N*m | uN*m | mN*m | kN*m | MN*m | GN*m | kgf*m | lbf*in | lbf*ft

Details

A vector of torque values for constructing an interpolation table of matching torque and speed values.

Units

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

[0.04, 0.035, 0.03, 0.025, 0.02, 0.015, 0.01, 0.005, 0.0, -0.005] N*m
Program usage name

torque_vector
Evaluatable

Yes

# Rated voltage — Rated voltage
V | uV | mV | kV | MV

Details

Specify the voltage for which the device being modeled is designed.

Units

V | uV | mV | kV | MV
Default value

12.0 V
Program usage name

V_rated
Evaluatable

Yes

# Motor efficiency (percent) — Engine EFFICIENCY

Details

The efficiency that the unit uses to calculate electrical losses that depend on the torque.

Default value

80.0
Program usage name

efficiency
Evaluatable

Yes

# Speed at which efficiency is measured — the speed at which efficiency is measured
rad/s | deg/s | rad/min | deg/min | rpm | rps

Details

The speed that the unit uses to calculate electrical losses that depend on the torque.

Units

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

2000.0 rpm
Program usage name

angular_velocity_reference_for_efficiency
Evaluatable

Yes

# Torque-independent electrical losses — fixed electrical losses
W | uW | mW | kW | MW | GW | V*A | HP_DIN

Details

Fixed electrical losses associated with the drive when the torque is zero.

Units

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

0.1 W
Program usage name

P_loss_base
Evaluatable

Yes

# Simulation mode — Simulation mode
PWM | Averaged

Details

If set for the parameter Simulation mode meaning PWM, then apply a PWM signal to the electrical terminals of the unit, switching between zero and rated voltage. The current consumed from the power grid is equal to the amount needed to transfer mechanical power and compensate for electrical losses. If the applied voltage exceeds the rated voltage, the resulting torque increases proportionally. However, applying a voltage other than the rated voltage may give unrepresentative results.

If you set the parameter Simulation mode in the value Averaged, then the torque generated in response to the applied voltage will be equal to:

ω

where ω — the value of the torque at speed ω . The current consumed from the power supply is such that the product of the current and is equal to the average power consumption.

Values

PWM | Averaged
Default value

PWM
Program usage name

simulation_mode
Evaluatable

No

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 changing the motion 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

0.0001 kg*m^2
Program usage name

J
Evaluatable

Yes

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

Details

Damping of 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-8 N*m*s/rad
Program usage name

damping
Evaluatable

Yes

Temperature Dependence

# Resistance temperature coefficient — temperature coefficient of resistance
1/K | 1/degR | 1/deltaK | 1/deltadegC | 1/deltadegF | 1/deltadegR

Details

Temperature coefficient of resistance.

Dependencies

To enable this option, check the box next to the Enable thermal port option.

Units

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

0.00393 1/K
Program usage name

alpha
Evaluatable

Yes

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

Details

The temperature for which the drive parameters are defined.

Dependencies

To enable this option, check the box next to the Enable thermal port option.

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 — turning on the heat port

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 mass — thermal mass
J/K | kJ/K

Details

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

Dependencies

To enable this option, check the box next to the Enable thermal port option.

Units

J/K | kJ/K
Default value

100.0 J/K
Program usage name

thermal_mass
Evaluatable

Yes