We claim:
1. A converter system (100) for driving a Switched Reluctance Machine
(SRM), the converter system (100) comprising:
a multi-phase power bridge circuit (110) comprising of a plurality of half bridge legs (104a, 104b, 104c, 104d….104n), each of the half bridge legs comprises of two switches ((M1,M2), (M3,M4), (M5,M6), (M7,M8)…. (Mn, Mn+1)), each of the two switches are connected to a common node (n1, n2, n3, n4….nn), wherein phase coils (L1, L2, L3…. Ln) of the SRM are connected between the consecutive nodes (n1, n2, n3, n4…nn), and wherein the number of half bridge legs is one more than the number of phases to be controlled; and
a power controller (106) configured to control triggering of the switches ((M1, M2), (M3, M4), (M5, M6), (M7, M8) …. (Mn, Mn+1)) of the multi-phase power bridge circuit (110) such that the phase coils (L1, L2, L3…. Ln) of the SRM are activated in series, wherein a maximum of two phases are activated at a time with an overlap in phase angles of phase coils (L1, L2, L3…. Ln) and energy is transferred in a single stage from an outgoing phase to an incoming phase, where current in the outgoing phase is falling and the current in the incoming phase is rising such that a net summation of the current and torque is constant and positive, thereby reducing torque ripple in the SRM.
2. The converter system (100) as claimed in claim 1, wherein the converter
system (100) has a linear configuration such that when the incoming phase
is energised, the outgoing phase has a voltage but does not conduct current
as diodes in the multi-phase power bridge circuit (110) are blocked, thereby
leading to phase independence by preventing current flow in the outgoing
phase that are not required to be activated.

3. The converter system (100) as claimed in claim 1, wherein the converter system (100) is configured to activate the maximum of two phases of the SRM at a time by energizing the incoming phase and the outgoing phase, and enabling faster current rise in the incoming phase as energy from the outgoing phase is pushed into the incoming phase.
4. The converter system (100) as claimed in claim 1, wherein the power controller (106) is configured to control triggering of the switches ((M1, M2), (M3, M4), (M5, M6), (M7, M8) …. (Mn, Mn+1)) such that a series current flows through a maximum of two phase coils of the phase coils (L1, L2, L3…. Ln).
5. The converter system (100) as claimed in claim 1, wherein the converter system (100) enables rotation of the SRM in a first direction by operating the outgoing and incoming phases as per a first pre-determined sequence of phase energization and enables rotation of the SRM in a reverse direction by operating the outgoing and incoming phases as per a second pre¬determined sequence of phase energization.
6. The converter system (100) as claimed in claim 1, wherein the power controller (106) is configured to provide a commutation angle of more than 120 electrical degrees and less than 180 electrical degrees for a three phase SRM and more than 90 electrical degrees and less than 180 electrical degrees for a four phase SRM, thereby providing an overlap between phases leading to the reduction in torque ripple.
7. A method for driving a Switched Reluctance Machine (SRM), the method comprising:
triggering a plurality of switches ((M1, M2), (M3, M4), (M5, M6), (M7, M8) …. (Mn, Mn+1)) of a converter system (100) such that phase coils of the SRM are activated in series; and
activating a maximum of two phases at a time with an overlap in phase angles of the phase coils and energy is transferred in a single stage

f p
from an outgoing phase to an incoming phase where current in the outgoing phase is falling and the current in the incoming phase is rising such that a net summation of the current and torque is constant and positive, thereby reducing torque ripple in the SRM.
8. The method as claimed in claim 7, wherein the method comprises:
(a) activating a first phase of the SRM by enabling flow of current through a first phase coil of the phase coils;
(b) activating a second phase of the SRM such that a phase overlap occurs between the first phase and the second phase;
(c) deactivating the first phase and activating a third phase such that a phase overlap occurs between the second phase and the third phase;
(d) activating the first phase and deactivating the third phase of the SRM by disabling flow of current through a third phase coil of the phase coils;
(e) repeating steps (a) to (d).
9. The method as claimed in claim 7, wherein the method comprises:
(a) activating a first phase of a three-phase SRM by enabling flow of current through a first phase coil of the phase coils;
(b) activating a second phase of the SRM such that a phase overlap occurs between the first phase and the second phase;
(c) deactivating the first phase and activating a third phase such that a phase overlap occurs between the second phase and the third phase;
(d) activating the first phase such that current flows from the switch M3 to the switch M2 and the third phase has current flow from the switch M5 and the switch M8;
(e) maintaining the first phase active and deactivating the third phase;
(f) activating the first and the second phases such that current flows through the switches M5 and M2 ;

(g) deactivating the first phase and maintaining the second phase as active;
(h) maintaining the second phase and the third phase active with current flowing from the switches M7 and M4 leading to overlap of the second and the third phases;
(i) deactivating the second phase and maintaining the third phase active; and
(j) repeating steps (a) to (i).