Single bus star connected reluctance drive and method
View Patent ↗A system and methods for operating a switched reluctance machine includes a controller, an inverter connected to the controller and to the switched reluctance machine, a hysteresis control connected to the controller and to the inverter, a set of sensors connected to the switched reluctance machine and to the controller, the switched reluctance machine further including a set of phases the controller further comprising a processor and a memory connected to the processor, wherein the processor programmed to execute a control process and a generation process.
1. A method for controlling a switched reluctance machine comprising the steps of:
determining a conduction band for an electrical phase angle for each phase of a set of phases;
enforcing a reference current in each phase of the set of phases;
determining a preemptive band for the electrical phase angle for each phase of the set of phases;
increasing the reference current to a preemptive reference current in each phase of the set of phases;
discharging the reference current from each phase of the set of phases;
wherein the preemptive reference current (i pre *) is in accordance with:
i
pre
*
=
2
i
*
1
+
e
L
k
k
θ
′
ω
+
R
k
L
k
k
t
discharge
;
wherein a time to discharge the current (y discharge ) is in accordance with:
t
discharge
=
-
L
j
j
L
j
j
θ
′
ω
+
R
j
ln
(
v
dc
v
d
c
+
i
*
(
L
j
j
θ
′
ω
+
R
j
)
)
;
and,
wherein currents of the switched reluctance machine during the time to discharge are in accordance with:
i
k
(
t
)
-
i
pre
*
e
-
L
k
k
θ
′
ω
+
R
k
L
k
k
t
;
i
j
(
t
)
i
*
e
L
j
j
θ
′
ω
+
R
j
L
j
j
t
+
-
v
d
c
L
j
j
θ
′
ω
+
R
j
(
1
-
e
-
L
j
j
θ
′
ω
+
R
j
L
j
j
t
)
.
2. The method of claim 1 , wherein the step of determining a conduction band for the electrical phase angle for each phase of the set of phases further comprises the steps of:
determining a starting angle of the conduction band; and
determining an ending angle of the conduction band.
3. The method of claim 2 , wherein the steps of enforcing a reference current in each phase of the set of phases, determining a preemptive band for the electrical phase angle for each phase of the set of phases, and increasing the reference current to a preemptive reference current in each phase of the set of phases, are performed when the electrical phase angle is greater than the starting angle and less than the ending angle.
4. The method of claim 2 , wherein the step of discharging the reference current from each phase of the set of phases is performed when the electrical phase angle is greater than the ending angle.
5. The method of claim 1 , wherein the step enforcing a reference current in each phase of the set of phases further comprises the step of applying a hysteresis control to enforce the reference current in each phase of the set of phases.
6. The method of claim 1 , wherein the steps of determining a preemptive band for the electrical phase angle for each phase of the set of phases further comprises the steps of:
determining a starting preemptive angle; and
determining an ending preemptive angle.
7. The method of claim 6 , wherein the step of increasing the reference current to a preemptive reference current in each phase of the set of phases is performed when the electrical phase angle is greater than the starting preemptive angle and less than the ending preemptive angle.
8. The method of claim 6 , further comprising the step of turning off a current in a phase i−1 when the electrical phase angle is greater than the starting preemptive angle and less than the ending preemptive angle.
9. A method for controlling a switched reluctance machine comprising the steps of:
determining a conduction band for an electrical phase angle for each phase of a set of phases;
increasing a first current in each phase of the set of phases;
determining a reference current for the first current in each phase of the set of phases;
enforcing the reference current on each phase of the set of phases;
determining a preemptive band for the electrical phase angle for each phase of the set of phases;
reducing the reference current to a preemptive current in each phase of the set of phases; and discharging the reference current from each phase of the set of phases;
wherein the preemptive current ( pre *) is in accordance with:
i
pre
*
=
2
i
*
1
+
e
L
k
k
θ
′
ω
+
R
k
L
k
k
t
discharge
;
wherein a time to discharge the current (t discharge ) is in accordance with:
t
discharge
=
-
L
j
j
L
j
j
θ
′
ω
+
R
j
ln
(
v
dc
v
d
c
+
i
*
(
L
j
j
θ
′
ω
+
R
j
)
)
;
and,
wherein currents of the switched reluctance machine during the time to discharge are in accordance with:
i
k
(
t
)
-
i
pre
*
e
-
L
k
k
θ
′
ω
+
R
k
L
k
k
t
;
i
j
(
t
)
i
*
e
L
j
j
θ
′
ω
+
R
j
L
j
j
t
+
-
v
d
c
L
j
j
θ
′
ω
+
R
j
(
1
-
e
-
L
j
j
θ
′
ω
+
R
j
L
j
j
t
)
.
10. The method of claim 9 , wherein the step of enforcing the reference current on each phase of the set of phases further comprises the steps of applying a hysteresis control to enforce the reference current in each phase of the set of phases.
11. The method of claim 9 , wherein the step of determining a conduction band for the electrical phase angle for each phase of the set of phases further comprises the steps of:
determining a starting angle of the conduction band; and
determining an ending angle of the conduction band.
12. The method of claim 11 , wherein the steps of increasing a current in each phase of the set of phases, determining a reference current for the current for each phase of the set of phases, enforcing the reference current on each phase of the set of phases, determining a preemptive band for the electrical phase angle for each phase of the set of phases, and reducing the reference current to a preemptive current in each phase of the set of phases, are performed when the electrical phase angle is greater than the starting angle and less than the ending angle.
13. The method of claim 11 , wherein the step of discharging the reference current from each phase of the set of phases is performed when the electrical phase angle is greater than the ending angle.
14. The method of claim 9 , wherein the step of determining a preemptive band for the electrical phase angle for each phase of the set of phases further comprises the steps of:
determining a starting preemptive angle; and
determining an ending preemptive angle.
15. The method of claim 14 , wherein the step of decreasing the reference current to a preemptive reference current in each phase of the set of phases is performed when the electrical phase angle is greater than the starting preemptive angle and less than the ending preemptive angle.
16. The method of claim 14 , further comprising the step of charging a phase i+1with a second current when the electrical phase angle is greater than the starting preemptive angle and less than the ending preemptive angle.
17. A system for operating a switched reluctance machine comprises:
a controller;
an inverter connected to the controller and to the switched reluctance machine;
a hysteresis control connected to the controller and to the inverter;
a set of sensors connected to the switched reluctance machine and to the controller;
the switched reluctance machine further comprising a set of phases;
the controller further comprising a processor and a memory connected to the processor;
wherein the processor is programmed to carry out the steps of:
determining a conduction band for an electrical phase angle for each phase of the set of phases;
enforcing a reference current in each phase of the set of phases;
determining a preemptive band for the electrical phase angle for each phase of the set of phases;
increasing the reference current to a preemptive reference current in each phase of the set of phases;
discharging the reference current from each phase of the set of phases;
wherein the preemptive reference current (i pre *) is in accordance with:
i
pre
*
=
2
i
*
1
+
e
L
k
k
θ
′
ω
+
R
k
L
k
k
t
discharge
;
wherein a time to discharge the current (t discharge ) is in accordance with:
t
discharge
=
-
L
j
j
L
j
j
θ
′
ω
+
R
j
ln
(
v
dc
v
d
c
+
i
*
(
L
j
j
θ
′
ω
+
R
j
)
)
;
and,
wherein currents of the switched reluctance machine during the time to discharge are in accordance with:
i
k
(
t
)
-
i
pre
*
e
-
L
k
k
θ
′
ω
+
R
k
L
k
k
t
;
i
j
(
t
)
i
*
e
L
j
j
θ
′
ω
+
R
j
L
j
j
t
+
-
v
d
c
L
j
j
θ
′
ω
+
R
j
(
1
-
e
-
L
j
j
θ
′
ω
+
R
j
L
j
j
t
)
.
18. The system of claim 17 , wherein the processor is further programmed to carry out the step of:
turning off a current in a phase i−1 during the preemptive band.
19. A system for operating a switched reluctance machine comprises:
a controller;
an inverter connected to the controller and to the switched reluctance machine;
a hysteresis control connected to the controller and to the inverter;
a set of sensors connected to the switched reluctance machine and to the controller;
the switched reluctance machine further comprising a set of phases;
the controller further comprising a processor and a memory connected to the processor;
wherein the processor is programmed to carry out the steps of:
determining a conduction band for an electrical phase angle for each phase of the set of phases;
increasing a first current in each phase of the set of phases;
determining a reference current for the first current in each phase of the set of phases;
enforcing the reference current on each phase of the set of phases;
determining a preemptive band for the electrical phase angle for each phase of the set of phases;
reducing the reference current to a preemptive reference current in each phase of the set of phases;
discharging the reference current from each phase of the set of phases;
wherein the preemptive reference current (i pre *) is in accordance with:
i
pre
*
=
2
i
*
1
+
e
L
k
k
θ
′
ω
+
R
k
L
k
k
t
discharge
;
wherein a time to discharge the current (t discharge ) is in accordance with:
t
discharge
=
-
L
j
j
L
j
j
θ
′
ω
+
R
j
ln
(
v
dc
v
d
c
+
i
*
(
L
j
j
θ
′
ω
+
R
j
)
)
;
and,
wherein currents of the switched reluctance machine during the time to discharge are in accordance with:
i
k
(
t
)
-
i
pre
*
e
-
L
k
k
θ
′
ω
+
R
k
L
k
k
t
;
i
j
(
t
)
i
*
e
L
j
j
θ
′
ω
+
R
j
L
j
j
t
+
-
v
d
c
L
j
j
θ
′
ω
+
R
j
(
1
-
e
-
L
j
j
θ
′
ω
+
R
j
L
j
j
t
)
.
20. The system of claim 19 , wherein the processor further programmed to carry out the step of:
charging a phase i+1 with a second current during the preemptive band.