Implement three-phase series RLC load with selectable connection
Simscape / Electrical / Specialized Power Systems / Fundamental Blocks / Elements
The Three-Phase Series RLC Load block implements a three-phase balanced load as a series combination of RLC elements. At the specified frequency, the load exhibits a constant impedance. The active and reactive powers absorbed by the load are proportional to the square of the applied voltage.
Only elements associated with nonzero powers are displayed in the block icon.
The connection of the three phases. Select one of the following four connections:
| Neutral is grounded. Default. |
| Neutral is not accessible. |
| Neutral is made accessible through a fourth connector. |
| Three phases connected in delta |
The block icon is updated according to the load connection.
The nominal phase-to-phase voltage of the load, in volts RMS
(Vrms). Default is 1000
.
The nominal frequency, in hertz (Hz). Default is 60
.
Select to specify active powers, inductive reactive powers, and capacitive reactive powers for each phase of the load. Default is cleared.
The three-phase active power of the load, in watts. This parameter
is visible only when Specify PQ powers for each phase is
cleared. Default is 10e3
.
The three-phase inductive reactive power QL, in vars. Specify
a positive value or 0. This parameter is visible only when Specify
PQ powers for each phase is cleared. Default is 100
.
The three-phase capacitive reactive power QC, in vars. Specify
a positive value or 0. This parameter is visible only when Specify
PQ powers for each phase is cleared. Default is 100
.
The three-phase active power of the load, in watts. Specify
three positive values. You can specify different powers for each phase,
including 0. This parameter is visible only when you select Specify
PQ powers for each phase. Default is [10e3 9e3
11e3]
.
The three-phase inductive reactive power QL, in vars. Specify
three positive values. You can specify different powers for each phase,
including 0. This parameter is visible only when you select Specify
PQ powers for each phase. Default is [100 90 110]
.
The three-phase capacitive reactive power QC, in vars. Specify
three positive values. You can specify different powers for each phase,
including 0. This parameter is visible only when you select Specify
PQ powers for each phase. Default is [100 90 110]
.
Select Branch voltages
to measure
the three voltages across each phase of the Three-Phase Series RLC
Load block terminals. For a Y connection, these voltages are the phase-to-ground
or phase-to-neutral voltages. For a delta connection, these voltages
are the phase-to-phase voltages.
Select Branch currents
to measure
the three total currents (sum of R, L, C currents) flowing through
each phase of the Three-Phase Series RLC Load block. For a delta connection,
these currents are the currents flowing in each branch of the delta.
Select Branch voltages and currents
to
measure the three voltages and the three currents of the Three-Phase
Series RLC Load block.
Default is None
.
Place a Multimeter block in your model to display the selected measurements during the simulation. In the Available Measurements list box of the Multimeter block, the measurements are identified by a label followed by the block name.
Measurement | Label | |
---|---|---|
Branch voltages | Y(grounded) |
|
Y(floating) |
| |
Y(neutral) |
| |
Delta |
| |
Branch currents | Y(grounded) |
|
Y(floating) |
| |
Y(neutral) |
| |
Delta |
|
The parameters on this tab are used by the Load Flow tool of the Powergui block. These load flow parameters are used for model initialization only, they have no impact on the block model and on the simulation performance.
Specify the load type.
If you select constant Z
(default),
the load impedance is determined from the nominal phase-to-phase voltage
Vn, active power P, and reactive power (QL-QC) specified on the Parameters tab
of the block dialog box. During the load flow solution, the impedance
is kept constant. The effective P and Q are therefore varying proportionally
to the square of the bus voltage computed by the Load Flow tool.
If you select constant PQ
, the active
power P and reactive power Q are kept constant and equal to the values
specified on the Parameters tab of the block
dialog box. When you apply the load flow solution to the model (by
clicking the Apply button of the Load Flow
tool), the Nominal phase-to-phase voltage Vn parameter
on the Parameters tab is automatically adjusted
to the phase-to-phase bus voltage computed by the Load Flow tool.
If you select constant I
, the load
current is kept constant at its nominal value determined from base
voltage specified in the dialog box of the associated Load Flow Bus
block and from active power P and reactive power QL and QC specified
on the Parameters tab of the block dialog box.
The effective P and Q are therefore varying proportionally to the
bus voltage computed by the Load Flow tool. When you apply the load
flow solution to the model (by clicking the Apply button
of the Load Flow tool), the p.u. value of the nominal voltage Vn on
the Parameters tab is automatically adjusted
to the square root of the load voltage (in pu) computed by the Load
Flow tool.
Multimeter, Three-Phase Dynamic Load, Three-Phase Parallel RLC Branch, Three-Phase Parallel RLC Load, Three-Phase Series RLC Branch