Stability Analysis of Single Inverter Fed Two Induction Motors in Parallel

This paper discusses the novel graphical approach for
stability analysis of multi induction motor drive controlled by a single
inverter. Stability issue arises in parallel connected induction motors
under unbalanced load conditions. The two powerful globally
accepted modeling and simulation software packages such as
MATLAB and LabVIEW are selected to perform the stability
analysis. The stability investigation is performed for different load
conditions and difference in stator and rotor resistances among the
two motors. It is very simple and effective than the techniques
presented to obtain the stability of the parallel connected induction
motor drive under unbalanced load conditions. Approximate transfer
functions are considered to model the induction motors, load
dynamics, speed controllers and inverter. Simulink library tools are
utilized to model the entire drive scheme in MATLAB. Stability
study is discussed in LabVIEW using control design and simulation
toolkits. Simulation results are illustrated for various running
conditions to demonstrate the effectiveness of the transfer function
method.

• R. Gunabalan
• V. Subbiah

• Induction motor
• Modeling
• Stability analysis
• Transfer function model.

[1] G K.Matsuse, Y.Kouno, H.Kawai, J.Oikawa, "Characteristics of speed
sensor-less vector controlled dual induction motor drive connected in
parallel fed by a single Inverter”, IEEE Trans. Ind. Appl., vol. 40, pp.
153-161, Jan./Feb. 2004.
[2] Wang Ruxi, Wang Yue, Dong Qiang He Yanhui and Wang Zhaoan,
"Study of control methodology for single inverter parallel connected
dual induction motors based on the dynamic model”, IEEE PESC’06,
2006.
[3] B. K. Bose, "Modern Power Electronics and AC Drives”, Upper Saddle
River, NJ: pp.348-350, Prentice-Hall, 2001.
[4] Yoshinaga T., Terunuma T. and Matsuse K., "Basic characteristic of
parallel connected dual induction motor drives with matrix converter”,
In: Proceedings of 34th Annual conference of IEEE Ind. Electronics,
2008, pp.584-589.
[5] Osawa A., Yamazaki M. and Matsuse K., "Vector control method of
parallel connected induction motor drives fed by a matrix converter”, In:
Proceedings of IEEE IAS meeting, Oct. 2011.
[6] Osawa A., Yamazaki M. and Matsuse K., "Vector control method and
driving characteristics of parallel connected induction motor drives fed
by a matrix converter”, In: Proceedings of IEEE power engineering
conference, 2011.
[7] Masao Yano, Satoru Kuramoti and Hiroyuki Matsuda, "Vector control
method of parallel connected induction motors”, Electrical engineering
report, pp. 34-39, NR-12, Nov.2001.
[8] H. Kubota, I.Sato, Y. Tamura, K.Matuse, H. Ohta and Y. Hori,
"Regenerative mode low speed operation of induction motor drive with
adaptive observer”, IEEE Trans. Ind. Appl., vol.38, no.4, pp.1081-1086,
July/Aug. 2002.
[9] Lennart Harnefors Marko Hinkkanen, "Complete stability of reducedorder
and full-order observers for sensorless IM drives”, IEEE Trans.
Ind. Eelectron., vol. 55, no. 3, pp.1319-1329, March 2008.
[10] Hisao Kubota, Kouki Matsuse and Takayoshi Nakano, " DSP-based
speed adaptive flux observer of induction motor”, IEEE Trans. Ind.
Appl., vol. 29, no. 2, pp.344-348, March/April 1993.
[11] P. Vaclavek and P. Blaha, "Lyapunov function based flux and speed
observer for AC induction motor sensorless control and parameter
estimation”, IEEE Trans. Ind. Electron., vol. 53, no.1, Feb. 2006.
[12] R. Krishnan, "Electric motor drives modeling, analysis and control”, pp.
492-501, PHI learning private limited, New Delhi, 2001.
[13] R. Gunabalan, V. Subbiah, "Speed sensorless vector control of parallel
connected induction motor drive with fuzzy controller”, In: Proceedings
of IEEE conference (ICCIC’12), 2012, pp. 473-478.
[14] Lab-view control design user manual, National Instruments, 2008.