The PLL, 3-ph component models a Phase Lock Loop (PLL) closed-loop control system, which tracks the frequency and phase of a sinusoidal signal by using an internal frequency oscillator.
The input signal u is mixed with an internal oscillator signal. The DC component of the mixed signal is extracted with a variable frequency mean value (Phase detector section). A Proportional-Integral-Derivative (PID) controller keeps the phase difference to 0 by acting on a controlled oscillator.
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Symbol
Mask Parameters
Main tab
| Name | Description | Unit | Variable = {Possible Values} | |
|---|---|---|---|---|
| Description | Use this field to add all kinds of information about the component | Description = {'string'} | ||
| Initial frequency | Initial frequency for the first simulation cycle. This value cannot be modified during the simulation | Hz | Finit = { [0, 1e12] } | |
| Minimum frequency | Minimum expected frequency of the input signal. This value cannot be modified during the simulation | Hz | Fmin = { [0, 1e12] } | |
| Initial phase | Initial value of the phase of the output signal for the first simulation cycle. This value cannot be modified during the simulation | deg. | InitialPhase = { [0, 360] } | |
PID Controller tab
| Name | Description | Unit | Variable = {Possible Values} | |
|---|---|---|---|---|
| Kp | Internal PID controller proportional gain | Kp = { [0, 1e12] } | ||
| Ki | Internal PID controller integral gain | Ki = { [0, 1e12] } | ||
| Kd | Internal PID controller derivative gain | Kd = { [0, 1e12] } | ||
| Lower limit | Lower limit of the PI integral action. This value cannot be modified during the simulation | LowerLimit = { [-1e64, 1e64] } | ||
| Upper limit | Upper limit of the PI integral action. This value should be greater than the value of the Lower limit parameter. This value cannot be modified during the simulation | UpperLimit = { [-1e64, 1e64] } | ||
| Initial condition | Integrator initial condition. This value cannot be modified during the simulation | Integrator_InitialCondition = { [0, 1e12] } | ||
| Time constant for derivative action | Time constant for the first-order filter of the derivative action from the internal PID controller | s | Tc_Derivative = { [0, 1e12] } | |
| Duration of initial value | Duration of the initial value of the internal PID controller output signal. This value cannot be modified during the simulation | s | Tinit = { [0, 1e12] } | |
Second-Order FIlter tab
| Name | Description | Unit | Variable = {Possible Values} | |
|---|---|---|---|---|
| Maximum rate of change of frequency | Maximum positive and negative slope of the frequency of the second-order low pass filter input signal | Hz/s | Freq_RateLimiter = { [0, 1e12] } | |
| Filter natural frequency | Internal second-order natural low-passe filter frequency | Hz | FreqFilter_fn = { [0, 1e12] } | |
| Filter damping ratio | Second-order low-pass filter damping rate. The damping ratio is typically a value between 0 and 1 | FreqFilter_zeta = { [0, 1] } | ||
Input/Output Signals
| Name | Description | Unit | Type |
|---|---|---|---|
| abc | Vectorized signal that can contain phase-to-ground voltages (Va, Vb and Vc) or phase-to-ground currents (Ia, Ib and Ic) | pu | Input |
| f | Measured frequency signal | Hz | Output |
| wt | Angle signal varying between 0 and 2 * pi, synchronized to the zero-crossing (ascending) of the fundamental of the input signal | rad | Output |
Sensor Descriptions
| Name | Description | Unit |
|---|---|---|
abc[a] | Input signal that may contain the voltage or current of phase A V or A | pu |
abc[b] | Input signal that may contain the voltage or current of phase B | V or Apu |
abc[c] | Input signal that may contain the voltage or current of phase C | V or Apu |
f | Measured frequency signal | Hz |
wt | Angle signal varying between 0 and 2 * pi, synchronized to the zero-crossing (ascending) of the fundamental of the input signal | rad |
Internal Circuit of Component
Limitations
In the PLL, 3-ph component, since the internal Proportional-Integral-Derivative (PID) controller has no automatic gain control, the input signal should be in pu and have a value not too distant from one.