blockRayleigh
Rayleigh wind distribution
Information
This block provides a discrete velocity distribution in the time domain according to a Rayleigh distribution
where 
is the approximate mean velocity of the distribution. The greater the number of velocity intervals 
and the greater the maximum velocity, 
, is, the more accurate is the approximation of the mean velocity. The velocity interval is determined by:
The sum of all probabilities 
is equal to one.
The boolean parameter increaseDecrease indicates whether
false: discrete velocities over time are only increasing in each period
, ortrue: discrete velocities over time are alternatingly increasing and decreasing, in every other period.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.Velocity | vMean | 5 | Mean velocity |
| Modelica.Units.SI.Velocity | vMax | 20 | Maximum velocity (v<=vMax) |
| Integer | n | 10 | Number of intervals |
| Modelica.Units.SI.Time | T | 100 | Time period |
| Boolean | increaseDecrease | false | If true, altering velocity increase and decrease after one period |
| Modelica.Units.SI.Velocity | dv | vMax/n | Velocity increment |
| Modelica.Units.SI.Velocity[n] | vDiscrete | array(k*dv for k in 1:n) | Discrete velocities |
| Real[n] | rayleigh | array(dv*pi/2*vDiscrete[k]/vMean^2*exp(-pi/4*vDiscrete[k]^2/vMean^2) for k in 1:n) | Rayleigh probaility |
| Real | rayleigh_sum | sum(rayleigh) | Sum of all rayleigh probabilities |
| Real[n] | probability | rayleigh/rayleigh_sum | Probabilities of velocities |
| Modelica.Units.SI.Time[n] | tDiscrete | probability*T | Discrete durations |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Blocks.Interfaces.RealOutput | v | Wind velocity |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Integer | counter | Counter of repeating velocity distribution after time T | |
| Integer | index | Velocity index | |
| Integer | increment | Increment of index | |
| Modelica.Units.SI.Time | tNext | Time of next event | |
| Modelica.Units.SI.Velocity | velocity | Velocity |