modelGenerator
Information
This model describes the conversion between mechanical power and electrical power in an ideal synchronous generator, with ideal voltage control. Only active power generation is considered.
For proper system initialization and operation, it is recommended to use the generator model to represent the overall inertia of the turbo-generator group, i.e., to connect the generator model to turbine models that do not have any inertia on their own.
The inertia of the turbo-generator group is characterized by the acceleration time Ta, which is defined as two times
the ratio between the turbo-group kinetic energy at nominal rotational speed and the nominal turbo-group power. Oftentimes, the time constant H
is given instead, which is defined as just the ratio between the turbo-group kinetic energy at nominal rotational speed and the nominal turbo-group power.
Obviously, Ta = 2*H. Typical values of Ta are beteween 5 s and 15 s.
In order to obtain well-posed initialization problems, it is also necessary to set referenceGenerator = true on one (and only one)
generator for each synchronously connected island at the initial time. This ensures that all initial voltage angles are well defined. Please note
this is not required if the generator belongs to a system connected to a Grid component,
as the grid provides a reference for the initial voltage angles.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| SI.Power | Pnom | Nominal/rated power of the generator | |
| SI.Time | Ta | 10 | Acceleration time of the turbo-generator group |
| Integer | Np | 2 | Number of electrical poles |
| SI.PerUnit | eta | 1 | Electrical conversion efficiency |
| SI.AngularVelocity | omega_e_nom | 2*pi*system.fnom | Nominal angular velocity of voltage vector |
| SI.AngularVelocity | omega_m_nom | 2*pi*system.fnom/Np | Nominal angular velocity of turbo-group |
| SI.MomentOfInertia | J | Pnom*Ta/omega_m_nom^2 | Turbo-generator group moment of inertia |
| SI.PerUnit | D | 0.01 | Damping coefficient |
| SI.Time | Tf | 1 | Time constant of omega_e_filt |
| SI.Torque | tau_d | 2*D*Pnom*sqrt(Ta/omega_m_nom) | |
| Boolean | referenceGenerator | false | Set to true if reference generator in a synchronous island |
| Real | pi | Modelica.Constants.pi | |
| Initialization | |||
| SI.Frequency | fstart | system.fnom | Start value of the electrical frequency |
| SI.Angle | thetastart | 0 | Start value of the voltage phasor angle |
| ThermoPower.Choices.Init.Options | initOpt | system.initOpt | Initialization option |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| PowerConnection | port | ||
| Modelica.Mechanics.Rotational.Interfaces.Flange_a | shaft |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| System | system | System object | |
| SI.Angle | theta | Voltage angle | |
| SI.Angle | phi | Shaft angle | |
| SI.Torque | tau | Torque at shaft | |
| SI.AngularVelocity | omega_m | Angular velocity of the shaft | |
| SI.AngularVelocity | omega_e | Angular velocity of the voltage phasor | |
| SI.Frequency | f | Electrical frequency | |
| SI.Power | Pm | Mechanical power | |
| SI.ActivePower | Pe | Electrical Power | |
| SI.ActivePower | Pd | Damping power | |
| SI.AngularVelocity | omega_e_filt | Low-pass filtered angular velocity of the voltage phasor | |
| SI.AngularVelocity | de | omega_e - omega_e_filt |
Revisions
- 21 Feb 2019
by Francesco
Casella:
Rewrote from scratch.