Implements five-phase inverter model for five-phase PM Synchronous motor drive
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The Inverter (Five-Phase) block models a standard five-leg, two-level inverter model when set to detailed mode or an average-value inverter model when set to average mode.
In detailed mode, this block consists of five Universal Bridge models configured as single-leg (one leg with two switches), force-commutated converters and connected in parallel.
In average mode, the Inverter (Five-phase) block implements an average-value inverter model where the inverter is represented using current and voltage sources, as shown in the figure.
The average-value model is composed of one controlled current source on the DC side and four controlled current sources and four controlled voltage sources on the AC side. The DC current source allows the representation of the average DC bus current behavior following the equation
Idc = (Pac + Plosses) / Vin,
with Plossesbeing the AC side instantaneous power, Plosses the losses in the power electronics devices, and Vin the DC bus voltage.
On the AC side, the current sources represent the average phase currents fed to the motor. Because the regulation is fast, the current values are set equal to the current references sent by the current regulator. A small current is injected to compensate for the current drawn by the five-phase load.
During loss of current tracking due to insufficient inverter voltage, the currents are fed by four controlled voltage sources. These voltage sources represent the square wave mode and allow good representation of the phase currents during inverter saturation. Each voltage source outputs either Vin or 0, depending on the values of the pulses (1 or 0) sent by the current controller. This mode of operation is detected by the Saturation detection block using the DC bus voltage and the counter electro-motive force generated by the AC machine.
Specify the model detail level to use:
Detailed
(default)
Average
The sample time of the inverter, in seconds. The default value
is 2e-6
.
The snubber resistance, in ohms. Set the Snubber resistance
Rs parameter to inf
to eliminate the
snubbers from the model. The default value is 500
.
The snubber capacitance, in farads. Set the Snubber
capacitance Cs parameter to 0
to eliminate
the snubbers or to inf
to get a resistive snubber.
The default value is 1e-9
.
Select the type of power electronic device to use in the inverter.
GTO / Diodes
(default)
MOSFET / Diodes
IGBT / Diodes
Internal resistance of the switch, in ohms. The default value
is 1e-3
.
Forward voltages, in volts, of the forced-commutated devices
(GTO, MOSFET, or IGBT) and of the antiparallel diodes. The default
value is [1.2,1.2]
.
Fall time Tf and tail time Tt, in seconds, for the GTO or the
IGBT devices. The default value is [1e-6,2e-6]
.
Synchronous frequency of the machine (Hz). This parameter is
visible only when the Model detail level parameter
is set to Average
. The default value is 60
.
The armature inductance of the sinusoidal model with round rotor
(Ld is equal to Lq). This parameter is visible only when the Model
detail level parameter is set to Average
.
The default value is 1350e-6
.
The constant flux, in weber, per pole pairs induced in the stator
windings by the magnets of the machine. This parameter is visible
only when the Model detail level parameter is
set to Average
. The default value is 0.05
.
The stator phase resistance Rs, in ohms, of the motor. This
parameter is visible only when the Model detail level parameter
is set to Average
. The default value is 0.12
.
The number of pole pairs of the machine controlled by the inverter.
This parameter is visible only when the Model detail level parameter
is set to Average
. The default value is 4
.
g
The gate input for the controlled switch devices. Pulses are
sent to upper and lower switches of inverter legs A, B, C, D, and
E. This input is visible only when the Model detail level parameter
is set to Detailed
.
ctrl
Control signals from the PMSM vector controller. In average
mode, the three-phase inverter no longer receives pulses for each
switch. The control signals are the AC current references for each
phase along with pulses (0 or 1) to enable square wave operating mode.
This input is visible only when the Model detail level parameter
is set to Average
.
+
The positive terminal on the DC side.
-
The negative terminal on the DC side.
A, B, C, D, E
The five-phase terminals on the AC side.
The Inverter (Five-Phase) block is used in the AC8 block of the Electric Drives library.
[1] Bose, B. K. Modern Power Electronics and AC Drives, NJ: Prentice-Hall, 2002.
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