MICROCONTROLLER BASED ONLINE IDENTIFICATION OF VARIABLE PARAMETERS IN INDUCTION MOTORS

ABSTRACT On-line identification of machine parameters has been a challenge in induction drives for the achievement of high performance operation of machines with variable parameters. Conventional recursive or iterative algorithms, in most cases, are not applicable because of computing time limitations and convergence problems. In addressing the issue of obtaining operating-condition dependent parameters in transportation linear induction motors (LIMs), this work proposes a microcontroller based on-line scheme, which is conceptually simple and operationally stable, for identification of key variable parameters, namely magnetizing inductance and secondary resistance, in induction motors. The algorithm is derived from the terminal equivalent impedance, and uniqueness is verified. A new algorithm for calculating Arctg(x) when x ≈ 1 is also derived to facilitate the real-time operations of microprocessor-based systems. The effectiveness of this new scheme is demonstrated by experimental results.

[1]  J. Duncan,et al.  Linear induction motor-equivalent-circuit model , 1983 .

[2]  G.C. Verghese,et al.  Recursive speed and parameter estimation for induction machines , 1989, Conference Record of the IEEE Industry Applications Society Annual Meeting,.

[3]  Graham E. Dawson,et al.  LIM dynamic performance assessment from parameter identification , 1993, Conference Record of the 1993 IEEE Industry Applications Conference Twenty-Eighth IAS Annual Meeting.

[4]  T. Matsui,et al.  An automated secondary resistance identification scheme in vector controlled induction motor drives , 1989, Conference Record of the IEEE Industry Applications Society Annual Meeting,.

[5]  Thomas A. Lipo,et al.  A Rotor Parameter Identification Scheme for Vector-Controlled Induction Motor Drives , 1985, IEEE Transactions on Industry Applications.

[6]  I Boldea,et al.  Linear Motion Electromagnetic Systems , 1985 .

[7]  J. Holtz,et al.  Identification of the machine parameters in a vector controlled induction motor drive , 1989, Conference Record of the IEEE Industry Applications Society Annual Meeting,.

[8]  Luis J. Garces.  Parameter Adaption for the Speed-Controlled Static AC Drive with a Squirrel-Cage Induction Motor , 1980, IEEE Transactions on Industry Applications.

[9]  Paresh C. Sen.  Electric motor drives and control-past, present, and future , 1990 .

[10]  M. Depenbrock,et al.  Determination of the induction machine parameters and their dependencies on saturation , 1989, Conference Record of the IEEE Industry Applications Society Annual Meeting,.

[11]  S. Nasar,et al.  A complete equivalent circuit of a linear induction motor with sheet secondary , 1988 .

[12]  M.U. Rao,et al.  Microprocessor based feedback control using reactive power measurement for squirrel cage induction motor drives , 1989, Conference Record of the IEEE Industry Applications Society Annual Meeting,.

[13]  Friedrich Loeser,et al.  Identification and Compensation of the Rotor Temperature of AC Drives by an Observer , 1985, IEEE Transactions on Industry Applications.

[14]  A. F. Puchstein,et al.  Alternating-current machines , 1942 .