Real-Time Analysis of a Nonlinear State Observer with Improved Disturbance Compensation for Sensorless Induction Motor

  • S. Mohan Krishna
  • J. L. Febin Daya
  • C. Kamal Basha
Conference paper
Part of the Advances in Intelligent Systems and Computing book series (AISC, volume 695)


This paper presents a comparison and real-time analysis of sliding mode disturbance observers for speed sensorless induction motor drives. The rotor speed tracking bandwidth and the load rejection capability are improved by altering the profile of the sliding hyperplane used in the state observer. The entire system is built in Simulink environment, and real-time RT-lab blocksets are integrated into the same and tested in a new Processor-in-Loop-based test bench. The Processor-in-Loop test bench uses the OP4500 real-time target and loop back adapters for signal routing. This ensures that there is a real-world signal transfer between the plant and the controller.


Sensorless State estimation Adaptive control Model-based design Processor-in-loop (PIL) RT-lab 


\( {\text{i}}_{\text{ds}}^{\text{s}} ,{\text{i}}_{\text{qs}}^{\text{s}} ,{\text{i}}_{\text{dr}}^{\text{r}} ,{\text{i}}_{\text{qr}}^{\text{r}} ,{\text{i}}_{\text{as}}^{\text{ * }} , {\text{i}}_{\text{bs}}^{\text{ * }} , {\text{i}}_{\text{cs}}^{\text{ * }} \)

D-, q-, and three-phase reference current components

\( {\text{v}}_{\text{ds}}^{\text{s}} ,{\text{v}}_{\text{qs}}^{\text{s}}\)

D- and q-axis stator voltage components

Tr,Rs, Rr

Rotor time constant, stator, and rotor resistance

Σ,Lr, Lm, Ls

Leakage reactance, rotor, magnetizing, and stator self-inductance


Stator and rotor leakage inductances

\({{\uppsi}}_{\text{ds}}^{\text{s}} ,{{\uppsi}}_{\text{qs}}^{\text{s}}, {{\uppsi}}_{\text{dr}}^{\text{s}}, {{\uppsi}}_{\text{qr}}^{\text{s}}\)

D-axis and q-axis flux linkages

\( \uptheta_{\text{f}} ,\uptheta_{\text{sl}} ,\uptheta_{\text{r}} \)\( {\text{T}}_{\text{e}}^{ *} \)

Field, slip, and rotor angle, reference electromagnetic torque


  1. 1.
    Krishna, M., Daya, J.L.F.: Dynamic performance analysis of mras based speed estimators for speed sensorless induction motor drives. In: IEEE International Conference on Advances in Electronics, Computers and Communication, pp 1–6 (2014)Google Scholar
  2. 2.
    Krishna, M., Daya, J.L.F.: MRAS speed estimator with fuzzy and PI stator resistance adaptation for sesnorless induction motor drives using RT-Lab. Perspectives in Science, pp. 121–126. Elsevier (2016)Google Scholar
  3. 3.
    Krishna, M., Daya, J.L.F.: An improved stator resistance adaptation mechanism in MRAS estimator for sensorless induction motor drives. In: Advances in Intelligent Systems and Computing, vol. 458, pp. 371–385. Springer-Verlag (2016)Google Scholar
  4. 4.
    Krishna, M., Daya, J.L.F., Sanjeevikumar, P., Mihet-Popa, L.: Real-time performance and analysis of a modified state observer for sensorless induction motor drives using RT-Lab for electric vehicle applications. Energies, MDPI, pp. 1–23 (2017)Google Scholar
  5. 5.
    Krishna, M., Daya, J.L.F.: Effect of Parametric variations and Voltage unbalance on adaptive speed estimation schemes for speed sensorless induction motor drives, pp. 77–85. IAES, Indonesia, Int. J. Power. Elect. Drive. Sys (2015)Google Scholar
  6. 6.
    Krishna, M., Daya, J.L.F.: A modified disturbance rejection mechanism in sliding mode state observer for sensorless induction motor drive. Arab. J. Sci. Eng. 3571–3586 (2016) (Springer-Verlag)Google Scholar
  7. 7.
    Krishna, M., Daya, J.L.F.: Adaptive speed observer with disturbance torque compensation for sensorless induction motor drives using RT-lab. Turk. J. Elect. Eng. Comp. Sci. Tubitak 3792–3806 (2016)Google Scholar
  8. 8.
    Slotine, J.J.E., Li, W.: Applied Non Linear Control. Prentice-Hall (1991)Google Scholar
  9. 9.
    Comanescu, M.: Design and analysis of a sensorless sliding mode flux observer for induction motor drives. In: IEEE International Electric Machines & Drives Conference, pp. 569–574 (2011)Google Scholar
  10. 10.
    Bose, B.K.: Power Electronics and Variable Frequency Drives—Technology and Applications. Wiley (2013)Google Scholar

Copyright information

© Springer Nature Singapore Pte Ltd. 2018

Authors and Affiliations

  • S. Mohan Krishna
    • 1
  • J. L. Febin Daya
    • 2
  • C. Kamal Basha
    • 1
  1. 1.Department of Electrical and Electronics EngineeringMITS (Madanapalle Institute of Technology and Science)MadanapalleIndia
  2. 2.School of Electrical EngineeringVIT UniversityChennaiIndia

Personalised recommendations