Skip to main content
SpringerLink
Log in

An improved approach to the prediction of line current spectrum in induction machines

  • Published:
Electrical Engineering Aims and scope Submit manuscript

Abstract

This paper concentrates on the estimation of the magnitude and frequency of the spectral components of line current that may be used for sensorless speed detection. The prediction method uses a mixture of permeance-magnetomotive force, finite element and reluctance mesh techniques to establish the airgap magnetic field. This traditional type of approach is chosen to maintain a visible link between cause and effect, so enhancing understanding of complex interactions. The approach is enhanced by the use of slot permeance effects calculated by finite element techniques, where saturation due to the current carrying conductors in the slots is incorporated. Further enhancements include examining slot permeance effects over one or more poles so that the influence of the spatial distribution of slot currents and slot top saturation can be incorporated. The large number of independent speed harmonic terms found experimentally in the line current spectrum is explained by rotor pole aliasing. Special equivalent circuits are introduced to enable these current harmonics to be predicted. A thorough experimental validation of the model is then conducted using a 30-kW experimental machine with adjustable eccentricity, rotors of different slotting form, slot number and skew to determine their effect on the speed-dependent harmonic components. Very good agreement was observed.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1.
Fig. 2.
Fig. 3.
Fig. 4.
Fig. 5.
Fig. 6.
Fig. 7.
Fig. 8.
Fig. 9.
Fig. 10.
Fig. 11.

Similar content being viewed by others

Abbreviations

B :

flux density

D :

diameter of stator bore

F :

magnetomotive force

I :

rms current

L :

length of machine

N ph :

number of series turn per phase

R :

number of rotor slot

S :

number of stator slot

Z :

impedance

e :

induced EMF

f :

frequency

k w , k p :

winding and pitch factors

l g :

airgap length

s :

slip

t :

time

v :

rms value of induced EMF

ε :

relative eccentricity

φ :

flux

Λ :

permeance

θ :

αngular distance

ω :

angular frequency

i, j, n, m :

integers

r:

for rotor

s:

for stator

h:

harmonic

sa:

saturation

se:

static eccentricity

so:

source

References

  1. Penman J, Dey MN (1986) Condition monitoring of electrical drives. IEE Proc B 133:142–148

    Google Scholar 

  2. Schoen RR, Habetler TG (1995) Effects of time varying loads on rotor fault detection in induction machines. IEEE Trans Ind Applic 31:900–906

    Article  Google Scholar 

  3. Schoen RR, Habetler TG (1995) Motor bearing damage detection using stator current monitoring. IEEE Trans Ind Applic 31:1274–1279

    Article  Google Scholar 

  4. Bradley KJ, Ferrah A, Asher GM (1992) Analysis of speed measurement using FFT spectral estimation for mains or inverter driven induction motors. In: International Conference on Electrical Machines (Icem'92), pp 923–927

  5. Blasco R, Sumner M, Asher GM (1994) Speed measurement of inverter fed induction motors using the FFT and the rotor slot harmonics. In: 5th International Conference on Power Electronics and Variable Speed Drives, pp 470–475

  6. Hillenbrand F (1983) A method for determining the speed and rotor flux of the asynchronous machine by measuring the terminal quantities only. IFAC, Control in Power Electronics and Electrical Drives, Lausanne, pp 55–62

  7. Guldemir H, Bradley KJ (2001) The effect of rotor design on rotor slot harmonics in induction machines. Electr Power Comp Syst 29:771–788

    Article  Google Scholar 

  8. Hurst KD, Habetler TG (1996) Sensorless speed measurement using current harmonic spectral estimation in induction machine drives. IEEE Trans Power Electron 11:66–73

    Article  Google Scholar 

  9. Beguenane R, Ghyselen C, Schoorens H (1994) Induction motor speed sensorless from supply current by utilising FFT algorithm. In: Symposium on Power Electronics, Electrical Drives, Advanced Electrical Motors, Taormina, Italy, pp 139–144

  10. Schauder C (1992) Adaptive speed identification for vector control of induction motors without rotational transducers. IEEE Trans Ind Applic 28:1054–1061

    Article  Google Scholar 

  11. Odok AM (1958) Stray load losses and stray torques in induction machines. IEE Proc 43–53

  12. Belmans R, Vandenput J, Geysen W (1987) Analysis of the audible noise of three phase squirrel cage induction motors supplied by inverters. IEEE Trans Ind Applic 23:842–847

    Google Scholar 

  13. Wallace AK, Martin LG (1990) Current harmonics and acoustic noise in ac adjustable speed drives. IEEE Trans Ind Applic 26:267–273

    Article  Google Scholar 

  14. Buck FGG (1979) Losses and parasitic torques in electric motors subjected to pwm waveforms. IEEE Trans Ind Applic 15:47–53

    Google Scholar 

  15. Robinson RB (1962) Harmonics in ac machines. IEE Proc 380–387

  16. Williamson S, Lim LH, Robinson MJ (1990) Finite element models for cage induction motor analysis. IEEE Trans Ind Applic 26:1007–1017

    Article  Google Scholar 

  17. Guldemir H (1999) Prediction of induction motor line current spectra from motor design data. PhD Thesis, University of Nottingham

  18. Guldemir H, Bradley KJ (1998) Estimation of rotor slot harmonic amplitudes and frequencies in the line current of induction motors. In: International Conference on Electrical Machines (ICEM'98), 1–3 September, Istanbul, Turkey, pp 209–214

Download references

Author information

Authors and Affiliations

  1. Technical Education Faculty, Department of Electronics and Computer Science, University of Firat, 23100, Elazig, Turkey

    H. Guldemir

  2. School of Electrical and Electronics Engineering, University of Nottingham, University Park, Nottingham, NG7 2RD, UK

    K. J. Bradley

Authors
  1. H. Guldemir
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. K. J. Bradley
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to H. Guldemir.

Appendix

Appendix

The motor parameters are shown in Table 2.

Table 2. Motor parameters
Full size table

The stator and rotor slot dimensions are shown in Table 3 and Fig. 12.

Table 3. Stator and rotor slot dimensions in cm
Full size table
Fig. 12.
figure 12

Stator and rotor slot

Full size image

Rights and permissions

Reprints and permissions

About this article

Cite this article

Guldemir, H., Bradley, K.J. An improved approach to the prediction of line current spectrum in induction machines. Electr Eng 86, 17–24 (2003). https://doi.org/10.1007/s00202-003-0180-8

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00202-003-0180-8

Keywords

Search

Navigation