The Power, pos-seq variable frequency component computes the positive-sequence power P (in watts) and reactive power Q (in vars) associated with a periodic set of three-phase voltages and currents.

P and Q are calculated by evaluating the positive-sequence of the input voltages and currents with a running window over one cycle of the fundamental frequency given by input f. The reference frame required for the computation is given by input wt.

The output is held constant to the specified Initial active power and Initial reactive power values for one cycle of the specified fundamental frequency.

Symbol

Mask Parameters

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 active power	Initial active power value of the magnitude of the output signal for the first simulation cycle. This value cannot be modified during the simulation	W	Pinit = { [-1e64 1e64] }
Initial reactive power	Initial reactive power value of the magnitude of the output signal for the first simulation cycle. This value cannot be modified during the simulation	Var	Qinit = { [-1e64 1e64] }

Input/Output Signals

Name	Description	Type
Vabc	Vectorized signal containing phase-to-ground voltages (Va, Vb and Vc)	Input
Iabc	Vectorized signal containing phase-to-ground currents (Ia, Ib and Ic)	Input
f	Frequency signal used to calculate the positive-sequence of the Vabc and Iabc signals	Input
wt	Angle of the reference signal used for the calculation of the positive-sequence of the Vabc and Iabc signals	Input
P	Signal containing the active power of the positive-sequence resulting from the variable frequency voltage and current signals	Output
Q	Signal containing the reactive power of the positive-sequence resulting from the variable frequency voltage and current signals	Output

Sensor Descriptions

Name	Description	Unit
Vabc[a]	Signal containing the voltage of phase A	V
Vabc[b]	Signal containing the voltage of phase B	V
Vabc[c]	Signal containing the voltage of phase C	V
Iabc[a]	Signal containing the current of phase A	A
Iabc[b]	Signal containing the current of phase B	A
Iabc[c]	Signal containing the current of phase C	A
f	Frequency signal used to calculate the positive-sequence of the Vabc and Iabc signals	Hz
wt	Angle of the reference signal used for the calculation of the positive-sequence of the Vabc and Iabc signals	rad/s
P	Signal containing the active power of the positive-sequence resulting from the voltage and current signals	W
Q	Signal containing the reactive power of the positive-sequence resulting from the voltage and current signals	Var

Internal Circuit of the Component

Example Model

This example demonstrates the usage of power calculation with variable frequency block. A 3-phase 240V, 60Hz source connected to a 3kW and 0.6kVar load is demonstrated with a time varying frequency. It can be seen that the power consumed changes with frequency.

Note that the following demo requires that users edit the ScopeView template, and replace the existing .oprec data source with the data generated during the simulation.

Power, pos-seq variable frequency