Single Phase PLL
Description of the Single Phase PLL component in Schematic Editor, which generates an output signal whose phase is related to the phase of an input signal.
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Description
The single phase PLL component has two operation modes, with enabled gain scheduling where P, I and D gains depend on error and will vary between lower and higher values. If the scheduling is disabled lower values of P, I and D gains will be used.
Single phase PLL component is based on Second Order Generalized integrator (SOGI). The second order generalized integrator has been widely used to implement grid synchronization for gridconnected converters.
A conceptual block diagram of the synchronous frame single phase PLL is shown in Figure 2.
The sinusoidal input value is represented by v_{i}. K is the damping factor of the SOGI algorithm. The αβ signals, generated by SOGI algorithm are transformed into directquadrature frame through the Park transformation.
The qaxis part of the signal in the dq reference frame, normalized with amplitude as the base value, represents the error signal which feeds the PID block. The goal of the PID is to keep qaxis part on the zero value, which captures whole input signal in daxis. Thus, daxis value represents value synchronized with the input signal.
Ports
 In (in)
 Sinusoidal input of the singlephase system whose phase and frequency is intended to
be extracted.
 Supported types: real.
 Vector support: no.
 Sinusoidal input of the singlephase system whose phase and frequency is intended to
be extracted.
 d (out)
 Output signal of the component related to the direct component of the αβframe
input.
 Supported types: real.
 Vector support: no.
 Output signal of the component related to the direct component of the αβframe
input.
 q (out)
 Output signal of the component related to the quadrature component of the αβ frame
input.
 Supported types: real.
 Vector support: no.
 Output signal of the component related to the quadrature component of the αβ frame
input.
 f (out)
 Frequency (Hz) of the singlephase input system.
 Supported types: real.
 Vector support: no.
 Frequency (Hz) of the singlephase input system.
 wt (out)
 Angle of the singlephase input system.
 Supported types: real.
 Vector support: no.
 Angle of the singlephase input system.
 sin(wt) (out)
 Value of the trigonometric function ‘sin’ applied to the value of the phase of the
singlephase system.
 Supported types: real.
 Vector support: no.
 Value of the trigonometric function ‘sin’ applied to the value of the phase of the
singlephase system.
Properties
 Gain scheduling
 Select for allowing for variable PID gains whose values depend on error amplitude. If this property is set to “Disable”, the gains of the PID controller will assume the lower values that are set on the component.
 Initial frequency
 Type in the initial frequency of the calculated PLL output signal.
 Max frequency change (+/)
 Type in the maximum range around the initial frequency that the input signal is allowed to vary.
 Initial amplitude
 Type in the initial amplitude of the calculated PLL output signal.
 Initial angle
 Type in the initial angle of the calculated PLL output signal.
 SOGI gain
 Type in the dumping factor to be applied to the SOGI algorithm.
 kp_PLL low
 Type in the lowest gain value to be applied to the proportional gain of the PID control block.
 kp_PLL high
 Type in the highest gain value to be applied to the proportional gain of the PID control block.
 ki_PLL low
 Type in the the lowest gain value to be applied to the integral gain of the PID control block.
 ki_PLL high
 Type in the the highest gain value to be applied to the integral gain of the PID control block.
 kd_PLL low
 Type in the the lowest gain value to be applied to the derivative gain of the PID control block.
 kd_PLL high
 Type in the highest gain value to be applied to the derivative gain of the PID control block.
 Derivative filter time constant

Type in the derivative lowpass filter time constant that is used to implement the derivative action since it is not possible to implement a transfer function like K_{d} . s. The implementation of a derivative action, therefore, is done as in:
Hence, if N is sufficiently large, u_{d} tends to the ideal implementation of a derivative action K_{d} . s.

 Lowpass cutoff vd
 Type in the cutoff frequency of the lowpass filter applied to the direct component of the dqframe input.
 Lowpass cutoff wPLL
 Type in the cutoff frequency of the lowpass filter applied to the internal angular frequency used to calculate the virtual β signal of the αβframe.
 Lowpass cutoff fPLL
 Type in the cutoff frequency of the lowpass filter applied to the frequency output by the component.
 Execution rate
 Type in the desired signal processing execution rate. This value must be compatible with other signal processing components of the same circuit: the value must be a multiple of the fastest execution rate in the circuit. There can be up to four different execution rates, but they must all be multiple of the basic simulation timestep. To specify the execution rate, you can use either decimal (e.g. 0.001) or exponential values (e.g. 1e3) in seconds. Alternatively, you can type in ‘inherit’ in which case the component will be assigned execution rate based on the execution rate of the components it is receiving input from.