WE CLAIM:
1. A method for real-time controlling a Switched Reluctance Machine (SRM) 102, the
method comprising:
receiving, by a processor, one or more electrical and mechanical parameters of an SRM 102 from one or more sensors and one or more constants of an SRM 102 from the database;
calculating, by the processor, relative rotor position using at least one or more
mechanical parameters;
determining, by the processor, whether the relative rotor position is within a stroke period of the SRM 102;
determining, by the processor, a phase inductance of the SRM 102 using at least the one or more electrical parameters, when the rotor position is within a stroke period;
determining, by the processor, an effective inverse inductance using at least the phase inductance;
determining, by the processor, a DC bus current and a rate parameter using at least the one or more electrical parameters measured in each interval corresponding to each value of maximum number of conducting phases;
determining, by the processor, whether the relative rotor position has reached end of electrical cycle;
determining, by the processor, a change in switching angles (ΔƟon, ΔƟoff) to maintain the average DC bus current at the defined value while minimizing the RMS DC bus current, when the rotor position has reached end of electrical cycle;
determining, by the processor, updated switching angles (Ɵon, Ɵoff) based on the change in switching angles (ΔƟon, ΔƟoff);
determining, by the processor, a switching state signal (s1, s2, …, sn) using at least updated switching angles (Ɵoff, Ɵon); and
controlling, by the processor, the SRM 102 according to the switching state signal (s1, s2, …, sn).
2. The method as claimed in claim 1, wherein, the SRM 102 operates in a generation mode.
3. The method as claimed in claim 1, wherein, the SRM 102 operates in a motoring mode.

4. The method as claimed in claim 2, wherein, operating the SRM 102 in the generation mode comprises applying voltage pulse to phase windings during falling duration of phase inductance profile.
5. The method as claimed in claim 3, wherein, operating the SRM 102 in motoring mode comprises applying voltage pulse to phase windings during rising duration of phase inductance profile.
6. The method as claimed in claim 2, wherein, when the SRM 102 is operated in the generation mode,
the one or more electrical parameters from the one or more sensors of the SRM 102 comprises:
phase currents (i1, i2, …, in) 211; a DC link voltage (Vdc); the one or more mechanical parameters from the one or more sensors of the SRM 102 comprises:
a mechanical rotor position (Ɵ) 213 of the SRM 102. one or more constants of the SRM 102 stored in database comprises: phase resistances (R1, R2, …. Rn); number of rotor poles (nr); a stroke period (Ɵs);
a pair of turn-on and turn-off switching angles (Ɵon, Ɵoff) during falling duration of phase inductance profile;
7. The method as claimed in claim 3, wherein, when the SRM 102 is operated in the
motoring mode,
the one or more electrical parameters from the one or more sensors of the SRM 102 comprises:
phase currents (i1, i2, …, in) 211; a DC link voltage (Vdc); the one or more mechanical parameters from the one or more sensors of the SRM 102 comprises;
a mechanical rotor position (Ɵ) 213 of the SRM 102; a mechanical rotor speed (ωm) 214 of the SRM 102; and a mechanical Torque (T) of the SRM 102.

one or more constants of the SRM 102 stored in database comprises: phase resistances (R1, R2, …. Rn); number of rotor poles (nr); a stroke period (Ɵs);
a pair of turn-on and turn-off switching angles (Ɵon, Ɵoff) during rising duration of phase inductance profile;
8. The method as claimed in claim 1, wherein, the electrical rotor position with respect to each phase of SRM (α1, α2, …., αn) is calculated using corresponding mechanical rotor position (Ɵ) 213, number of rotor poles (nr) and stroke period (Ɵs).
9. The method as claimed in claim 1, wherein, determining the phase inductance of each phase comprises:
determining phase voltages using the relative rotor position, a DC link voltage (Vdc) 212 and the switching angles (Ɵon, Ɵoff);
determining an updated phase flux-linkage using phase voltages, phase currents (i1, i-2, …, in) 211 and phase resistances (R1, R2, …. Rn);
and determining the phase inductance based on the updated phase flux-linkage and phase current.
10. The method as claimed in claim 1, wherein, determining the effective inverse
inductance (Linv1, Linv2, … Linvn) comprises:
determining maximum number of conducting phases in a stroke interval (nc) using the switching angles (Ɵon, Ɵoff) and stroke angle (Ɵs);
and determining the effective inverse inductance using conducting phases (nc) and the phase inductance (L1, L2, ..., Ln).
11. The method as claimed in claim 1, wherein, determining the rate parameter indicating
rate of change of the DC bus current comprises:
determining the sampling instants (γ1, γ2, … γn) indicating start or end or both instants of one or more intervals using conducting phases (nc), the switching angles (Ɵon, Ɵoff) and the stroke angle (Ɵs);
determining effective phase currents (is1, is2 … isn) using sampling instants (γ1, γ2, … γn) and phase currents (i1, i2, …, in) 211;

determining instantaneous DC bus current (idc) using the phase currents (i1, i2, …, in)
211 and conducting phases (nc) in the one or more intervals (Int-1, Int-2, … Int-n) or using a
current sensor;
and determining the rate parameters using effective phase currents (is1, is2, …, isn) , effective inverse inductances (Linv1, Linv2, … Linvn), the instantaneous DC bus current (idc) and a DC link voltage (Vdc) 212.
12. The method as claimed in claim 1, wherein, instantaneous DC bus current (idc) is integrated to determine an average value of total instantaneous DC bus current (idc.avg) of the SRM 102.
13. The method as claimed in claim 1, wherein, determining whether the relative rotor position of the SRM 102 has reached end of electrical cycle (2π) comprises:
determining whether the relative rotor position indicating electrical rotor position with respect to any one phase (α1, α2, … αn) of the SRM 102 has reached end of electrical cycle (2π).
14. The method as claimed in claim 1, wherein, determining the change in the switching
angles (ΔƟon, ΔƟoff) for controlling of the DC bus current of the SRM 102 running in generation
mode comprises;
determining the change in the switching angles indicating the change in the switching angles (ΔƟon, ΔƟoff) using an average reference DC bus current (idc,avg,ref), rate parameters (rate1, rate2, rate3, rate4), and an average DC bus current (idc,avg).
15. The method as claimed in claim 1, wherein, determining the change in angle indicating
the change in the switching angles (ΔƟon, ΔƟoff) for controlling of DC link voltage (Vdc) 212
of the SRM 102 running in generation mode comprises;
determining an average reference DC bus current (idc,avg,ref) using DC link voltage (Vdc)
212 and a reference DC link voltage (Vdc.ref);
and determining the change in the switching angles (ΔƟon, ΔƟoff) using average reference DC bus current (idc,avg,ref), rate parameters (rate1, rate2, rate3, rate4), and an average DC bus current (idc,avg).
16. The method as claimed in claim 1, wherein, determining the change in the switching
angles indicating the change in the switching angles (ΔƟon, ΔƟoff) for controlling speed of the
SRM 102 running in motoring mode comprises;

determining average reference DC bus current (idc,avg,ref) using rotor speed (ωm) and a reference rotor speed (ωm,ref);
and determining the change in switching angles (ΔƟon, ΔƟoff) using average reference DC bus current (idc,avg,ref), rate parameters (rate1, rate2, rate3, rate4), and an average DC bus current (idc,avg).
17. The method as claimed in claim 1, wherein, determining the change in the switching
angles (ΔƟon, ΔƟoff) for controlling torque of the SRM 102 running in motoring mode comprises:
determining average reference DC bus current (idc,avg,ref) using rotor torque (T) and a reference rotor torque (Tref);
and determining the change in switching angles (ΔƟon, ΔƟoff) using average reference DC bus current (idc,avg,ref), rate parameters (rate1, rate2, rate3, rate4), and an average DC bus current (idc,avg).
18. The method as claimed in claim 1, wherein, determining the updated switching angles
(Ɵon, Ɵoff) comprises:
adding the change in angles (ΔƟon, ΔƟoff) with the switching angles (Ɵon, Ɵoff).
19. The method as claimed in claim 1, wherein, determining switching state signal (s1, s2, …, sn) based on updated switching angles (Ɵon, Ɵoff).
20. The method as claimed in claim 1, wherein, controlling electrical and mechanical output of the SRM 102 according to switching state signals (s1, s2, …, sn).
21. An apparatus comprising a processor 203 and a memory, wherein the processor 203 is configured to:
receive one or more electrical and mechanical parameters of an SRM 102 from one or more sensors and one or more constants from a database;
calculate relative rotor position using at least one or more mechanical parameters;
determine whether the relative rotor position is within a stroke period of the SRM 102;
determine a phase inductance of the SRM 102 using at least the one or more electrical parameters, when the rotor position is within a stroke period;
determine an effective inverse inductance using at least the phase inductance;
determine a DC bus current and a rate parameter using at least one or more electrical parameters measured in each interval corresponding to each value of conducting phase (nc);

determine whether the relative rotor position has reached end of electrical cycle;
determine a change in switching angles (ΔƟon, ΔƟoff) to maintain the DC bus current at defined value, when the rotor position has reached end of electrical cycle;
determine an updated switching angles (Ɵon, Ɵoff) based on the change in the switching angles (ΔƟon, ΔƟoff);
determine a switching state signal (s1, s2, …, sn) using at least updated switching angles (Ɵoff, Ɵon); and
controlling the SRM 102 according to the switching state signal (s1, s2, …, sn).
22. The apparatus as claimed in claim 21, wherein, the processor 203 is configured to operate the SRM 102 in generation mode, wherein, the processor 203 is configured to apply voltage pulse to phase windings at position ahead of maximum phase inductance.
23. The apparatus as claimed in claim 21, wherein, the processor 203 is configured to operate the SRM 102 in motoring mode, wherein, the processor 203 is configured to apply the voltage pulse to phase windings at position ahead of minimum phase inductance.
24. The apparatus as claimed in claim 22, wherein, the processor 203 is configured to control the SRM 102,
wherein the voltage pulse is applied to the phase windings of the SRM during falling duration of phase inductance profile to operate the SRM 102 in generation mode and the voltage pulse is applied to the phase windings of the SRM 102 during rising duration of the phase inductance profile to operate the SRM 102 in motoring mode.
25. The apparatus as claimed in claim 22, wherein, when the processor 203 is configured
to operate the SRM 102 in the generation mode,
the one or more electrical parameters from the one or more sensors of the SRM 102 comprises:
phase currents (i1, i2, …, in) 211; a DC link voltage (Vdc) 212; the one or more mechanical parameters from the one or more sensors of the SRM 102 comprises:
a mechanical rotor position (Ɵ) of the SRM 102. one or more constants of the SRM stored in database comprises: phase resistances (R1, R2, …. Rn);

number of rotor poles (nr); a stroke period (Ɵs);
a pair of turn-on and turn-off switching angles (Ɵon, Ɵoff) during falling duration of phase inductance profile;
26. The apparatus as claimed in claim 23, wherein, the processor 203 is configured to
operate the SRM in the motoring mode,
the one or more electrical parameters from the one or more sensors of the SRM 102 comprises:
phase currents (i1, i2, …, in) 211;
a DC link voltage (Vdc) 212; the one or more mechanical parameters from the one or more sensors of the SRM 102 comprises;
a mechanical rotor position (Ɵ) 213 of the SRM 102;
a mechanical rotor speed (ωm) 214 of the SRM 102; and
a mechanical Torque (T) of the SRM 102. one or more constants of the SRM stored in database comprises:
phase resistances (R1, R2, …. Rn);
number of rotor poles (nr);
a stroke period (Ɵs);
a pair of turn-on and turn-off switching angles (Ɵon, Ɵoff) during rising duration of phase inductance profile;
27. The apparatus as claimed in claim 21, wherein, the processor 203 is configured to calculate electrical rotor position (α) with respect to each phase (α1, α2, …., αn) using corresponding mechanical rotor position (Ɵ) 213, number of rotor poles (nr) and stoke period (Ɵs).
28. The apparatus as claimed in claim 21, wherein, the processor 203 is configured to determine the phase inductance of each phase based on phase voltages, phase currents 211 and updated phase flux-linkage, wherein, the processor 203 is configured to:
determine the phase voltages based on the relative rotor position, DC link voltage (Vdc) 212 and the switching angles (Ɵon, Ɵoff),
determine updated phase flux-linkage based on the phase voltages, phase currents 211 and phase resistances.

29. The apparatus as claimed in claim 21, wherein, the processor 203 is configured to
determine the effective inverse inductance (Linv1, Linv2, … Linvn) based on conducting phases
(nc) and the phase inductance (L1, L2, ..., Ln), wherein, the processor 203 is configured to:
determine the conducting phases (nc) based on the switching angles (Ɵon, Ɵoff) and stroke angle (Ɵs).
30. The apparatus as claimed in claim 21, wherein, the processor 203 is configured to
determine the rate parameter using effective phase currents (is1, is2, …, isn) , effective inverse
inductance (Linv1, Linv2, … Linvn), DC bus current (idc) and DC link voltage (Vdc) 212, wherein,
the processor 203 is configured to: determine sampling instants (γ1, γ2, … γn) based on the
conducting phases (nc), the switching angles (Ɵon, Ɵoff) and the stroke angle (Ɵs),
determine the effective phase currents (is1, is2, …, isn) based on the sampling instants (γ1, γ2, … γn) and the phase currents (i1, i2, …, in) 211,
determine the DC bus current based on phase currents (i1, i2, …, in) 211, the conducting phases (nc) in one or more intervals (Int-1, Int-2, … Int-n) or using a current sensor.
31 The apparatus as claimed in claim 21, wherein, the processor 203 is configured to determine an average value of total instantaneous DC bus current (idc,avg) of the SRM 102 through integrating DC bus current(idc).
32. The apparatus as claimed in claim 21, wherein, the processor 203 is configured to
determine whether the relative rotor position of the SRM 102 has reached end of electrical
cycle (2π), wherein,
the processor 203 configured to determine the relative rotor position indicating electrical position of rotor with respect to any one phase (α1 or α2 or … or αn) of the SRM 102 has reached end of electrical cycle (2π).
33. The apparatus as claimed in claim 21, wherein, the processor 203 is configured to determine the change in the switching angles (ΔƟon, ΔƟoff) for controlling of DC bus current of the SRM 102 running in generation mode based on an average reference DC bus current (idc,avg,ref), rate parameters (rate1, rate2, rate3, rate4), and an average DC bus current (idc,avg).
34. The apparatus as claimed in claim 20, wherein, the processor 203 is configured to determine the change in the switching angles (ΔƟon, ΔƟoff) for controlling of DC link voltage (Vdc) 212 of the SRM 102 running in generation mode based on an average reference DC bus

current(idc,avg,ref), rate parameters (rate1, rate2, rate3, rate4), and an average DC bus current (idc,avg). wherein,
determine an average reference DC bus current (idc,avg,ref) based on DC link voltage (Vdc) 212 and a reference voltage (Vdc.ref).
35. The apparatus as claimed in claim 21, wherein, the processor 203 is configured to determine the change in the switching angles (ΔƟon, ΔƟoff) for controlling speed of the SRM 102 running in motoring mode based on an average reference DC bus current (idc,avg,ref), rate parameters (rate1, rate2, rate3, rate4), and an average DC bus current (idc,avg).36. The apparatus as claimed in claim 35, wherein, the processor 203 is configured to determine the average reference DC bus current (idc,avg,ref) using the mechanical rotor speed (ωm) and a reference rotor speed (ωref).
37. The apparatus as claimed in claim 21, wherein, the processor 203 is configured to
determine the change in the switching angles (ΔƟon, ΔƟoff) for controlling torque of the SRM
102 running in motoring using average reference DC bus current (idc,avg,ref), rate parameters
(rate1, rate2, rate3, rate4), and an average DC bus current (idc,avg).
wherein, the processor 203 is configured to determine average reference DC bus current (idc,avg,ref) using rotor torque (T) and a reference rotor torque (Tref);
38. The apparatus as claimed in claim 21, wherein, the processor 203 is configured to determine the updated switching angles (Ɵon, Ɵoff) by adding the change in angles (ΔƟon, ΔƟoff) with the switching angles (Ɵon, Ɵoff).
39. The apparatus as claimed in claim 21, wherein, the processor 203 is configured to determine switching state signal (s1, s2, …, sn) based on updated switching angles (Ɵon, Ɵoff).
40. The apparatus as claimed in claim 21, wherein, the processor 203 is configured to control electrical and mechanical output of the SRM 102 according to switching state signals (s1, s2, …, sn).

41. A system for optimal control of SRM comprises: a Switched Reluctance Machine (SRM) 102; one or more sensors; a processor 203 configured to perform method steps of 1-20.