Modelica.Electrical.Analog.Basic

Basic electrical components

Information

This package contains very basic analog electrical components such as resistor, conductor, capacitor, inductor, and the ground (which is needed in each electrical circuit description. Furthermore, controlled sources, coupling components, and some improved (but nevertheless basic) are in this package.

Extends from Modelica.Icons.Package (Icon for standard packages).

Package Content

Name	Description
Ground	Ground node
Resistor	Ideal linear electrical resistor
HeatingResistor	Temperature dependent electrical resistor
Conductor	Ideal linear electrical conductor
Capacitor	Ideal linear electrical capacitor
Inductor	Ideal linear electrical inductor
SaturatingInductor	Simple model of an inductor with saturation
Transformer	Transformer with two ports
M_Transformer	Generic transformer with free number of inductors
Gyrator	Gyrator
EMF	Electromotoric force (electric/mechanic transformer)
TranslationalEMF	Electromotoric force (electric/mechanic transformer)
VCV	Linear voltage-controlled voltage source
VCC	Linear voltage-controlled current source
CCV	Linear current-controlled voltage source
CCC	Linear current-controlled current source
OpAmp	Simple nonideal model of an OpAmp with limitation
OpAmpDetailed	Detailed model of an operational amplifier
VariableResistor	Ideal linear electrical resistor with variable resistance
VariableConductor	Ideal linear electrical conductor with variable conductance
VariableCapacitor	Ideal linear electrical capacitor with variable capacitance
VariableInductor	Ideal linear electrical inductor with variable inductance
Potentiometer	Adjustable resistor
GeneralCurrentToVoltageAdaptor	Signal adaptor for an Electrical OnePort with voltage and derivative of voltage as outputs and current and derivative of current as inputs (especially useful for FMUs)
GeneralVoltageToCurrentAdaptor	Signal adaptor for an Electrical OnePort with current and derivative of current as output and voltage and derivative of voltage as input (especially useful for FMUs)

Modelica.Electrical.Analog.Basic.Ground

Ground node

Information

Ground of an electrical circuit. The potential at the ground node is zero. Every electrical circuit has to contain at least one ground object.

Connectors

Modelica.Electrical.Analog.Basic.Resistor

Ideal linear electrical resistor

Information

The linear resistor connects the branch voltage v with the branch current i by i*R = v. The Resistance R is allowed to be positive, zero, or negative.

Extends from Modelica.Electrical.Analog.Interfaces.OnePort (Component with two electrical pins p and n and current i from p to n), Modelica.Electrical.Analog.Interfaces.ConditionalHeatPort (Partial model to include a conditional HeatPort in order to describe the power loss via a thermal network).

Parameters

Connectors

Modelica.Electrical.Analog.Basic.HeatingResistor

Temperature dependent electrical resistor

Information

This is a model for an electrical resistor where the generated heat is dissipated to the environment via connector heatPort and where the resistance R is temperature dependent according to the following equation:

    R = R_ref*(1 + alpha*(heatPort.T - T_ref))

alpha is the temperature coefficient of resistance, which is often abbreviated as TCR. In resistor catalogues, it is usually defined as X [ppm/K] (parts per million, similarly to percentage) meaning X*1e-6 [1/K]. Resistors are available for 1 .. 7000 ppm/K, i.e., alpha = 1e-6 .. 7e-3 1/K;

Via parameter useHeatPort the heatPort connector can be enabled and disabled (default = enabled). If it is disabled, the generated heat is transported implicitly to an internal temperature source with a fixed temperature of T_ref.

If the heatPort connector is enabled, it must be connected.

Extends from Modelica.Electrical.Analog.Interfaces.OnePort (Component with two electrical pins p and n and current i from p to n), Modelica.Electrical.Analog.Interfaces.ConditionalHeatPort (Partial model to include a conditional HeatPort in order to describe the power loss via a thermal network).

Parameters

Connectors

Modelica.Electrical.Analog.Basic.Conductor

Ideal linear electrical conductor

Information

The linear conductor connects the branch voltage v with the branch current i by i = v*G. The Conductance G is allowed to be positive, zero, or negative.

Extends from Modelica.Electrical.Analog.Interfaces.OnePort (Component with two electrical pins p and n and current i from p to n), Modelica.Electrical.Analog.Interfaces.ConditionalHeatPort (Partial model to include a conditional HeatPort in order to describe the power loss via a thermal network).

Parameters

Connectors

Modelica.Electrical.Analog.Basic.Capacitor

Ideal linear electrical capacitor

Information

The linear capacitor connects the branch voltage v with the branch current i by i = C * dv/dt. The Capacitance C is allowed to be positive or zero.

Extends from Interfaces.OnePort (Component with two electrical pins p and n and current i from p to n).

Parameters

Connectors

Modelica.Electrical.Analog.Basic.Inductor

Ideal linear electrical inductor

Information

The linear inductor connects the branch voltage v with the branch current i by v = L * di/dt. The Inductance L is allowed to be positive, or zero.

Extends from Interfaces.OnePort (Component with two electrical pins p and n and current i from p to n).

Parameters

Connectors

Modelica.Electrical.Analog.Basic.SaturatingInductor

Simple model of an inductor with saturation

Information

This model approximates the behaviour of an inductor with the influence of saturation, i.e., the value of the inductance depends on the current flowing through the inductor (Fig. 1). The inductance decreases as current increases. Note, that hysteresis is not taken into account.

The approximation of the flux linkage is based on the atan function with an additional linear term, as shown in Fig. 2:

Psi = Linf*i + (Lzer - Linf)*Ipar*atan(i/Ipar)
L = Psi/i = Linf + (Lzer - Linf)*atan(i/Ipar)/(i/Ipar)

This approximation is with good performance and easy to adjust to a given characteristic with only four parameters (Tab. 1).

The parameter Ipar is calculated internally from the relationship:

Lnom = Linf + (Lzer - Linf)*atan(Inom/Ipar)/(Inom/Ipar)

Fig. 1: Actual inductance Lact versus current i

Fig. 2: Actual flux linkage Psi versus current i

The flux slope in Fig. 2 is equal to Lzer for small currents. The limit of the flux slope is Linf as the current i approaches infinity. The nominal flux is indicated by the product of the nominal inductance Lnom and the nominal current Inom.

Extends from Modelica.Electrical.Analog.Interfaces.OnePort (Component with two electrical pins p and n and current i from p to n).

Parameters

Name	Description
Inom	Nominal current [A]
Lnom	Nominal inductance at Nominal current [H]
Lzer	Inductance near current=0 [H]
Linf	Inductance at large currents [H]

Connectors

Modelica.Electrical.Analog.Basic.Transformer

Transformer with two ports

Information

The transformer is a two port. The left port voltage v1, left port current i1, right port voltage v2 and right port current i2 are connected by the following relation:

         | v1 |         | L1   M  |  | i1' |
         |    |    =    |         |  |     |
         | v2 |         | M    L2 |  | i2' |

L1, L2, and M are the primary, secondary, and coupling inductances respectively.

Extends from Interfaces.TwoPort (Component with two electrical ports, including current).

Parameters

Connectors

Modelica.Electrical.Analog.Basic.M_Transformer

Generic transformer with free number of inductors

Information

The model M_Transformer is a model of a transformer with the possibility to choose the number of inductors. Inside the model, an inductance matrix is built based on the inductance of the inductors and the coupling inductances between the inductors given as a parameter vector from the user of the model.

An example shows that approach:
The user chooses a model with three inductors, that means the parameter N has to be 3. Then he has to specify the inductances of the three inductors and the three coupling inductances. The coupling inductances are no real existing devices, but effects that occur between two inductors. The inductances (main diagonal of the inductance matrix) and the coupling inductances have to be specified in the parameter vector L. The length dimL of the parameter vector is calculated as follows: dimL=(N*(N+1))/2

The following example shows how the parameter vector is used to fill in the inductance matrix. To specify the inductance matrix of a three inductances transformer (N=3):

the user has to allocate the parameter vector L[6] , since Nv=(N*(N+1))/2=(3*(3+1))/2=6. The parameter vector must be filled like this: L=[1,0.1,0.2,2,0.3,3] .

Inside the model, two loops are used to fill the inductance matrix to guarantee that it is filled in a symmetric way.

Parameters

Connectors

Modelica.Electrical.Analog.Basic.Gyrator

Gyrator

Information

A gyrator is a two-port element defined by the following equations:

    i1 =  G2 * v2
    i2 = -G1 * v1

where the constants G1, G2 are called the gyration conductance.

Extends from Interfaces.TwoPort (Component with two electrical ports, including current).

Parameters

Connectors

Modelica.Electrical.Analog.Basic.EMF

Electromotoric force (electric/mechanic transformer)

Information

EMF transforms electrical energy into rotational mechanical energy. It is used as basic building block of an electrical motor. The mechanical connector flange can be connected to elements of the Modelica.Mechanics.Rotational library. flange.tau is the cut-torque, flange.phi is the angle at the rotational connection.

Parameters

Connectors

Modelica.Electrical.Analog.Basic.TranslationalEMF

Electromotoric force (electric/mechanic transformer)

Information

EMF transforms electrical energy into translational mechanical energy. It is used as basic building block of an electrical linear motor. The mechanical connector flange can be connected to elements of the Modelica.Mechanics.Translational library. flange.f is the cut-force, flange.s is the distance at the translational connection.

Parameters

Connectors

Modelica.Electrical.Analog.Basic.VCV

Linear voltage-controlled voltage source

Information

The linear voltage-controlled voltage source is a TwoPort. The right port voltage v2 is controlled by the left port voltage v1 via

    v2 = v1 * gain. 

The left port current is zero. Any voltage gain can be chosen.

Extends from Interfaces.TwoPort (Component with two electrical ports, including current).

Parameters

Connectors

Modelica.Electrical.Analog.Basic.VCC

Linear voltage-controlled current source

Information

The linear voltage-controlled current source is a TwoPort. The right port current i2 is controlled by the left port voltage v1 via

    i2 = v1 * transConductance. 

The left port current is zero. Any transConductance can be chosen.

Extends from Interfaces.TwoPort (Component with two electrical ports, including current).

Parameters

Connectors

Modelica.Electrical.Analog.Basic.CCV

Linear current-controlled voltage source

Information

The linear current-controlled voltage source is a TwoPort. The right port voltage v2 is controlled by the left port current i1 via

    v2 = i1 * transResistance. 

The left port voltage is zero. Any transResistance can be chosen.

Extends from Interfaces.TwoPort (Component with two electrical ports, including current).

Parameters

Connectors

Modelica.Electrical.Analog.Basic.CCC

Linear current-controlled current source

Information

The linear current-controlled current source is a TwoPort. The right port current i2 is controlled by the left port current i1 via

    i2 = i1 * gain. 

The left port voltage is zero. Any current gain can be chosen.

Extends from Interfaces.TwoPort (Component with two electrical ports, including current).

Parameters

Connectors

Modelica.Electrical.Analog.Basic.OpAmp

Simple nonideal model of an OpAmp with limitation

Information

The OpAmp is a simple nonideal model with a smooth out.v = f(vin) characteristic, where "vin = in_p.v - in_n.v". The characteristic is limited by VMax.v and VMin.v. Its slope at vin=0 is the parameter Slope, which must be positive. (Therefore, the absolute value of Slope is taken into calculation.)

Parameters

Connectors

Modelica.Electrical.Analog.Basic.OpAmpDetailed

Detailed model of an operational amplifier

Information

The OpAmpDetailed model is a general operational amplifier model. The emphasis is on separating each important data sheet parameter into a sub-circuit independent of the other parameters. The model is broken down into five functional stages input, frequency response, gain, slew rate and an output stage. Each stage contains data sheet parameters to be modeled. This partitioning and the modelling of the separate submodels are based on the description in [CP92].

Using [CP92] Joachim Haase (Fraunhofer Institute for Integrated Circuits, Design Automation Division) transferred 2001 operational amplifier models into VHDL-AMS. Now one of these models, the model "amp(macro)" was transferred into Modelica.

Reference:

[CP92] Conelly, J.A.; Choi, P.: Macromodelling with SPICE. Englewood Cliffs: Prentice-Hall, 1992

Parameters

Connectors

Modelica.Electrical.Analog.Basic.VariableResistor

Ideal linear electrical resistor with variable resistance

Information

The linear resistor connects the branch voltage v with the branch current i by
i*R = v
The Resistance R is given as input signal.

Attention!!!
It is recommended that the R signal should not cross the zero value. Otherwise depending on the surrounding circuit the probability of singularities is high.

Extends from Modelica.Electrical.Analog.Interfaces.OnePort (Component with two electrical pins p and n and current i from p to n), Modelica.Electrical.Analog.Interfaces.ConditionalHeatPort (Partial model to include a conditional HeatPort in order to describe the power loss via a thermal network).

Parameters

Connectors

Modelica.Electrical.Analog.Basic.VariableConductor

Ideal linear electrical conductor with variable conductance

Information

The linear conductor connects the branch voltage v with the branch current i by
i = G*v
The Conductance G is given as input signal.

Attention!!!
It is recommended that the G signal should not cross the zero value. Otherwise depending on the surrounding circuit the probability of singularities is high.

Extends from Modelica.Electrical.Analog.Interfaces.OnePort (Component with two electrical pins p and n and current i from p to n), Modelica.Electrical.Analog.Interfaces.ConditionalHeatPort (Partial model to include a conditional HeatPort in order to describe the power loss via a thermal network).

Parameters

Connectors

Modelica.Electrical.Analog.Basic.VariableCapacitor

Ideal linear electrical capacitor with variable capacitance

Information

The linear capacitor connects the branch voltage v with the branch current i by
i = dQ/dt with Q = C * v.
The capacitance C is given as input signal. It is required that C ≥ 0, otherwise an assertion is raised. To avoid a variable index system, C = Cmin, if 0 ≤ C < Cmin, where Cmin is a parameter with default value Modelica.Constants.eps.

Besides the Cmin parameter the capacitor model has got the two parameters IC and UIC that belong together. With the IC parameter the user can specify an initial value of the voltage over the capacitor, which is defined from positive pin p to negative pin n (v=p.v - n.v).

Hence the capacitor is charged at the beginning of the simulation. The other parameter UIC is of type Boolean. If UIC is true, the simulation tool uses

the IC value at the initial calculation by adding the equation v= IC. If UIC is false, the IC value can be used (but it does not need to!) to calculate the initial values in order to simplify the numerical algorithms of initial calculation.

Extends from Modelica.Electrical.Analog.Interfaces.OnePort (Component with two electrical pins p and n and current i from p to n).

Parameters

Connectors

Modelica.Electrical.Analog.Basic.VariableInductor

Ideal linear electrical inductor with variable inductance

Information

The linear inductor connects the branch voltage v with the branch current i by
v = d Psi/dt with Psi = L * i .
The inductance L is as input signal. It is required that L ≥ 0, otherwise an assertion is raised. To avoid a variable index system, L = Lmin, if 0 ≤ L < Lmin, where Lmin is a parameter with default value Modelica.Constants.eps.

Besides the Lmin parameter the inductor model has got the two parameters IC and UIC that belong together. With the IC parameter the user can specify an initial value of the current that flows through the inductor.

Hence the inductor has an initial current at the beginning of the simulation. The other parameter UIC is of type Boolean. If UIC is true, the simulation tool uses

the IC value at the initial calculation by adding the equation i= IC. If UIC is false, the IC value can be used (but it does not need to!) to calculate the initial values in order to simplify the numerical algorithms of initial calculation.

Extends from Modelica.Electrical.Analog.Interfaces.OnePort (Component with two electrical pins p and n and current i from p to n).

Parameters

Connectors

Modelica.Electrical.Analog.Basic.Potentiometer

Adjustable resistor

Information

This models a potentiometer where the sliding contact is placed between pin_n (r = 0) and pin_p (r = 1), dependent on either the parameter rConstant or the signal input r.

The total resistance R is temperature dependent.

Extends from Modelica.Electrical.Analog.Interfaces.ConditionalHeatPort (Partial model to include a conditional HeatPort in order to describe the power loss via a thermal network).

Parameters

Connectors

Modelica.Electrical.Analog.Basic.GeneralCurrentToVoltageAdaptor

Signal adaptor for an Electrical OnePort with voltage and derivative of voltage as outputs and current and derivative of current as inputs (especially useful for FMUs)

Information

Adaptor between an electrical oneport and a signal representation of the oneport. This component is used to provide a pure signal interface around an Electrical model and export this model in form of an input/output block, especially as FMU (Functional Mock-up Unit). Examples of the usage of this adaptor are provided in Electrical.Analog.Examples.GenerationOfFMUs. This adaptor has current and derivative of current as inputs and voltage and derivative of voltage as output signals.

Note, the input signals must be consistent to each other (di=der(i)).

Note, the adaptor contains no ground. Bear in mind that separating physical components and connecting them via adaptor signals requires to place appropriate ground components to define electric potential within the subcircuits.

Extends from Modelica.Blocks.Interfaces.Adaptors.FlowToPotentialAdaptor (Signal adaptor for a connector with flow, 1st derivative of flow, and 2nd derivative of flow as inputs and potential, 1st derivative of potential, and 2nd derivative of potential as outputs (especially useful for FMUs)).

Parameters

Connectors

Modelica.Electrical.Analog.Basic.GeneralVoltageToCurrentAdaptor

Signal adaptor for an Electrical OnePort with current and derivative of current as output and voltage and derivative of voltage as input (especially useful for FMUs)

Information

Adaptor between an electrical openport and a signal representation of the oneport. This component is used to provide a pure signal interface around an Electrical model and export this model in form of an input/output block, especially as FMU (Functional Mock-up Unit). Examples of the usage of this adaptor are provided in Electrical.Analog.Examples.GenerationOfFMUs. This adaptor has voltage and derivative of voltage as input signals and current and derivative of current as output signal.

Note, the input signals must be consistent to each other (dv=der(v)).

Note, the adaptor contains no ground. Bear in mind that separating physical components and connecting them via adaptor signals requires to place appropriate ground components to define electric potential within the subcircuits.

Extends from Modelica.Blocks.Interfaces.Adaptors.PotentialToFlowAdaptor (Signal adaptor for a connector with potential, 1st derivative of potential, and 2nd derivative of potential as inputs and flow, 1st derivative of flow, and 2nd derivative of flow as outputs (especially useful for FMUs)).

Parameters

Connectors