CLAIMS
WE CLAIM:
1. A switchover asymmetric H-Bridge circuit (200) for operation of a switched
reluctance motor (SRM) comprising:
5 a plurality of windings arranged on each phase of a switched reluctance motor
(SRM) motor; and wherein the plurality of windings of each phase of the SRM
motor comprises of a plurality of sub-windings or segments of equal turns; and
wherein each of the plurality of sub-windings is controlled individually by an
asymmetric H-Bridge circuit;
10 wherein the asymmetric H-Bridge circuit comprises a plurality of switches
configured with a plurality of diodes; and wherein the asymmetric H-Bridge
circuit, configuring each of the plurality of sub-windings is connected to each
other through a plurality of cross-over switches; and wherein the connection
between the asymmetric H-Bridge circuit, configuring the plurality of sub15 windings with the plurality of cross-over switches is established by connecting
an end of one segment of the plurality of sub-windings and a start of the next
segment of the plurality of sub-windings; and wherein the connection between
the plurality of sub-windings through the plurality of cross-over switches
provides an option to perform both series and parallel mode of operation for
20 each phase of the SRM to vary the inductance and torque or speed performance;
and wherein the each of the series-parallel combination of the plurality of subwindings with the plurality of cross-over switches is considered as a gear setting,
and wherein the gear setting with the plurality of sub-windings in series is
considered as a lower gear and the gear setting with the plurality of sub25 windings in parallel is considered as a higher gear.
2. The system (200) according to Claim 1, wherein the asymmetric H-Bridge circuit
with the plurality of cross-over switches is configured to achieve higher inductance
and torque at lower speeds, and lower inductance and torque at higher speeds of
operation.
5 3. The system (200) according to Claim 1, wherein the plurality of cross-over switches
used to connect asymmetric H-Bridge circuit to support series and parallel mode of
operation for each phase of SRM, comprises two cross-over switches; and wherein
the plurality of cross-over switches includes MOSFETs, SCR, Thyristor or Solidstate relays.
10 4. The system (200) according to Claim 1, wherein the plurality of cross-over switches
is used as bi-directional blocking devices and slow switching devices; and wherein
the use of the plurality of cross-over switches as bi-directional blocking devices, is
achieved by coupling the two cross-over switches in opposite directions.
5. The system (200) according to Claim 1, wherein the plurality of switches in the
15 asymmetric H-Bridge circuit includes MOSFETs, Power BJTs, IGBTs, SiC
MOSFETs or GaN MOSFETs; and wherein the plurality of diodes is used in the
asymmetric H-Bridge circuit to conduct current in one direction.
6. The system (200) according to Claim 1, wherein the plurality of sub-windings
connected through the plurality of cross-over switches in series mode, achieves
20 higher effective inductance or torque at lower speeds; and wherein the effective
inductance of the plurality of windings in series mode is twice the inductance of
each of the plurality of sub-windings.
7. The system (200) according to Claim 1, wherein the plurality of sub-windings
connected through the plurality of cross-over switches in parallel mode, achieves
25 lower effective inductance or torque at higher speeds; and wherein the effective inductance of the plurality of windings in parallel mode is half the inductance of
each of the plurality of sub-windings.
8. The system (200) according to Claim 1, wherein the asymmetric H-Bridge circuit
with the plurality of cross-over switches is configured to connect the plurality of
5 sub-windings in the series or parallel mode to achieve a wider range of inductance
variation; and wherein the number of sub-windings is selected/chosen based on user
requirement; and wherein the number of plurality of sub-windings, connected in
series or parallel are increased, by using additional asymmetric H-Bridge circuits
and the plurality of cross-switches.
10 9. A method (500) for operation of a switched reluctance motor (SRM) using
switchover asymmetric H-Bridge circuit comprising the steps of:
a. configuring a plurality of windings on each phase of a SRM motor (502);
and wherein the plurality of windings of each phase of the SRM comprises
of a plurality of sub-windings or segments of equal turns;
15 b. controlling individually each of the plurality of sub-windings by an
asymmetric H-Bridge circuit (504);
c. configuring the asymmetric H-Bridge circuit with a plurality of switches and
a plurality of diodes (506);
d. connecting the asymmetric H-Bridge circuit, configuring each of the
20 plurality of sub-windings through a plurality of cross-over switches (508);
and wherein the connection between the asymmetric H-Bridge circuit,
configuring plurality of sub-windings through the plurality of cross-over
switches is established by connecting an end of one segment of the plurality
of sub-windings and a start of the next segment of the plurality of sub25 windings; and
e. performing both series and parallel mode of operation for each phase of the
SRM to vary the inductance and torque or speed performance (510); and
wherein the each of the series-parallel combination of the plurality of subwindings with the plurality of cross-over switches is considered as a gear
5 setting, and wherein the gear setting with the plurality of sub-windings in
series is considered as a lower gear and the gear setting with the plurality of
sub-windings in parallel is considered as a higher gear; and wherein the
different gear settings are switched mutually to achieve the application
demands of the SRM motor in an optimal manner.
10 10. The method (500) according to Claim 9, wherein the required inductance or torque
is achieved by:
a. measuring current torque and speed, and estimating a commanded torque;
b. evaluating and continuing to function normally, when the commanded torque
and speed is within the capability of current inductance;
15 c. increasing inductance by determining whether the commanded torque level
is above maximum torque at current speed level, and the current speed level
is below a maximum speed limit at next higher gear; and
d. reducing inductance by determining whether the current speed level is above
the maximum speed limit at the current torque level, and the commanded
20 torque level is below the maximum torque level at next lower gear.