Analysis and Improvement of Low-Frequency Control of Speed-Sensorless AC Drive Fed by Three-Level Inverter

  • 발행 : 2005.12.01

초록

In induction machine drive without a speed sensor, the estimation of the motor flux and speed often becomes deteriorated at low speeds with low back EMF. Our analysis shows that, in addition to the state resistance variation, the estimated value of field orientation angle is often corrupted by accumulative errors from the integration of voltage variables at motor terminals that have low signal/noise ratio at low frequencies. A repetitive loop path of integration in the feedback can amplify this type of error, thus speeding up the degradation process. The control system runs into information starvation due to the loss of correct field orientation. The machine's spiral vectors are controlled only in a reduced dimension in this situation. A novel control scheme is developed to improve the control performance of motor's current, torque and speed at low frequencies. The scheme gains a full-dimensional vector control and is less sensitive to the combined effect of the error sources at the low frequencies. Experimental tests demonstrate promising performances are achievable even below 0.5 Hz.

키워드

참고문헌

  1. F. Blaschke, 'A New Method for The Structure Decoupling of AC Induction Machines,' 2nd IFAC on Multi-variable Tech. Control Systems, Pt 3, pp11-13, Oct. 1971
  2. R. Jotten and G. Maeder, 'Control Methods for Good Dynamic Performance of Induction Motor Drives Based on Current and Voltage As Measured Quantities,' IEEE Trans. lAS Vol. IA-19, No.3, 1983, pp. 356-363
  3. A. Abbondanti and M. B. Brennen, 'Variable Speed Induction Motor Drives Use Electronic Slip Calculator Based on Motor Voltage and Currents,' IEEE Trans. lAS, Vol. IA-11, No.5, 1975, pp. 483-488
  4. T. M. Rowan, R.J. Kerkman, 'A New Synchronous Current Regulator and an Analysis of Current-Regulated PWM Inverters,' IEEE Trans. Ind. Appl., vol. 22, 1986, pp.678-690 https://doi.org/10.1109/TIA.1986.4504778
  5. L. Xu, R. D. Doncker and D. W. Novotny, 'A Stator Flux Oriented Induction Machine Drive,' PESC' 88 Conference Record, pp. 870-876 https://doi.org/10.1109/PESC.1988.18219
  6. C. D. Schauder, 'Adaptive Speed Identification for Vector Control of Induction Motors Without Rotational Transducers,' 1989 IEEE lAS Conf. Record, pp. 491-499 https://doi.org/10.1109/IAS.1989.96696
  7. X. Xu and D. W. Novotny, 'Implementation of Direct Stator Flux Orientation Control on a Versatile DSP Based System,' IEEE Trans. lAS, Vol. 27, No. 4, July/August 1991, pp. 694-700
  8. H. Nakano and I. Takahashi, 'Sensorless Field Oriented Control of An Induction Motor Using An Instantaneous Slip Frequency Estimation Method,' 1988 IEEE PESC Record, pp. 847-854 https://doi.org/10.1109/PESC.1988.18216
  9. J.C. Moreira, K.T. Hung, T.A. Lipo and R.D. Lorenz, 'A Simple and Robust Adaptive Controller for Detuning Correction in Field Oriented Induction Machines,' 1991 IEEE lAS Annual Meeting Conference, pp. 397-403
  10. R.J. Kerkman, B.J. Seibel, T. M. Rowan and D. Schlegel, 'A New Flux And Stator Resistor Identifier For AC Drive Systems,' 1995 IEEE lAS Conf., pp. 310-318
  11. Jie Zhang (Chang), 'High Performance Control of A Three-Level IGBT Inverter Fed AC Drive,' IEEE lAS Annual Meeting Conference Record, 1995, pp. 22-28
  12. Jie Zhang (Chang) and T. H. Barton, 'Microprocessor Based Primary Current Control for A Cage Induction Motor Drive,' IEEE Trans. on Power Electronics, Vol. 4, No.1, Jan. 1989, pp. 73-82 https://doi.org/10.1109/63.21874