State Estimation in Induction Motors Using the Closed Loop Observers

Abstract

This paper presents an estimation technique for the state variables of a three phase squirrel-cage induction motor such as stator current and, rotor flux components. Closed loop observers, which can be classified as full-order and reduced-order observers, are used for estimation. In observer design, the state-space d-q axis model of induction motor is used. Estimation algorithms given for either observer are implemented by using MATLAB software.

In the estimation algorithms, some results for different observer gain matrices are obtained from input/output data of the state-space simulation of induction motor supplied by sinusoidal voltage sources.

It is shown that estimation results are compatible with the simulation results of induction motor.

Keywords

• Induction Motor,Closed-Loop Observer,Full rank observer

References

1. [1] BOSE, B.K., Modern power electronics and ac drives, Prentice-Hall Inc., USA, 2002.
2. [2] MATSUO, T., LIPO, T.A., A rotor parameter identification scheme for vector-controlled induction motor drives, IEEE Trans. On Ind. Appl., Vol. IA-21, No. 4, pp. 612-614, 1985.
3. [3] ZAMARA, J.L., CERRADA, G., Online estimation of the stator parameters in an induction motor using only voltage and current measurements, IEEE Trans. On Ind. Appl., Vol. 36, No. 3, 2000.
4. [4] ROBOAM, X., ANDRIEUX, C., de FORNEL, B., HAPIOT, J.C., Rotor flux observation and control in squirrel-cage induction motor: reliability with respect to parameters variations, IEEE Proceedings, Vol. 139, No. 4, 1992.
5. [5] IWASAKI, T., KATAOKA, T., Application of an extended Kalman filter to parameter identification of an induction motor, IEEE, pp. 248-253, 1989.
6. [6] PARK, R.H., Two reaction theory of synchronous machines, AIEE Transactions, 48, pp. 716-730, 1929.
7. [7] KEYHANI, A., TSAI, H., IGSPICE simulation of induction machines with saturable inductances, IEEE Transactions on Energy Conversion, Vol.4, No.1, pp. 118-125, 1989.
8. [8] LIPO, T.A., CONSOLI, A., Modeling and simulation of induction motors with saturable leakage reactances, IEEE Transactions on Industry Applications, Vol. IA-20, No.1, pp. 180-189, 1984.

9. [9] PAREKH, R., AC induction motor fundamentals, Microchip Technology Inc., AN887, pp. 1-2, 2003.
10. [10] ONG, C.M., Digital simulation of electric machinery, Prentice-Hall Inc., pp. 170-180, New Jersey, USA, 1998.
11. [11] OKORO, O.I., MATLAB simulation of induction machine with saturable leakage and magnetizing inductances, The Pacific Journal of Science and Technology, Vol. 5, No. 1, p. 7, Enugu State, Nigeria, 2003.
12. [12] LUENBERGER, D.G., Introduction to dynamic systems, John Wiley, pp. 301-303, USA, 1979.
13. [13] LUENBERGER, D.G., Observing the state of a linear system, IEEE Transactions on Military Electronics, Vol. 8, pp. 74-80, 1964.
14. [14] OGATA, K., Modern Control Engineering, Prentice-Hall Inc., 3rd ed., p. 832, New Jersey, USA, 1997.