![](bg5.png)
Table 1: Experimental Results for 2 cv Motor.
f
s
n measure (rpm) n estimated (rpm) τ measured(Nm) τ estimated (Nm) error (%)
59.992 1792 1790 0.82 1.01 23
60.005 1782 1782 2.02 1.94 3.96
59.978 1764 1763 4.03 3.95 1.99
59.978 1744 1744 6.03 6.04 0.17
60.031 1724 1723 8.08 8.28 2.48
60.005 1696 1696 10.05 11.23 11.74
60.024 1667 1666 12.01 14.44 20.23
to accuracy of manufacturer data.
7 CONCLUSION
The estimation methods of torque and speed are suf-
ficiently accurate inside operation nominal band of
three-phase induction motors. The use of these meth-
ods makes possible the GP supervision without the
installation of encoders, tachometers or torquimeters.
This means cost reduction of systems like SGPA in
GP wells.
A next step is the test of the system using frequency
inversor and its evaluation on the wells. It is intended
also improvement of hardware using a dedicated sub-
system. This subsystem must be built with microcon-
troller and digital signal processor (DSP). The com-
plete system will be used in the supervision of ap-
proximately 200 oil wells installed in Bahia State, in
Brazil.
ACKNOWLEDGEMENTS
The authors would like to thank in order the Finan-
ciadora de Estudos e Projetos (FINEP), the PETRO-
BRAS S. A., and the Conselho Nacional de Desen-
volvimento Cient
´
ıfico e Tecnol
´
ogico, all of Brazil, by
their support for this work.
REFERENCES
Alegre, L., Morooka, C. K., and Rocha, A. F. (1993). In-
telligent diagnosis of rod pumping problems. In Pro-
ceedings of the Annual Technical Conference and Ex-
hibition of the Society of Petroleum Engineers, pages
97–107, Houston, USA.
Benbouzid, M. E. (2000). A review of induction motors sig-
nature analysis as a medium for faults detection. IEEE
Transations on Industrial Electronics, 47(5):984–993.
Blasco-Gimenez, R., Asher, G. M., Summer, M., and
Bradley, K. J. (1996). Performance of FFT-rotor slot
harmonic speed detector for sensorless induction mo-
tor drives. IEE-Proceedings on Electronic Power Ap-
plied, 11(1):66–73.
Cerqueira, J. J. F., Corr
ˆ
ea, J. F., Lepkison, H., Bitencourt,
A. C., and Schnitman, L. (2002a). Development of an
intelligent distribuited manegement system for auto-
mated wells. In Proceedings of the Annual Technical
Conference and Exhibition of the Society of Petroleum
Engineers, pages 3053–3058, San Antonio, USA.
Cerqueira, J. J. F., Jesus, A., Dantas, E., Pereira, C. H.,
Albuquerque, G., Bitencourt, A. C., Pereira, F., Lep-
kison, H., and Corr
ˆ
ea, J. F. (2002b). An intelligent
distributed system applied on automated lift system.
In Proceedings of the WSEAS International Confer-
ence on System Science 2002, pages 1951–1955, Rio
de Janeiro, Brazil.
Cerqueira, J. J. F., Jesus, A., Dantas, E., Pereira, C. H.,
Albuquerque, G., Bitencourt, A. C., Pereira, F., Lep-
kison, H., and Corr
ˆ
ea, J. F. (2003). An intelligent
distributed system applied on automated lift system.
WSEAS Transactions on Systems, 2(2):482–486.
Cerqueira, J. J. F., Lepkison, H., Corr
ˆ
ea, J. F., Biten-
court, A. C., Reis, A. C., Jesus, A., Fisch, M., Dan-
tas, E., Pereira, C. H., Albuquerque, G., and Pereira,
F. (2002c). Sistema de gerenciamento de poos de
petr
´
oleo automatizados. In Anais do XIV Congresso
Brasileiro de Autom
´
atica, pages 3053–3058, Natal-
RN, Brazil.
Damasceno, S. M. N. (2002). Uma contribuio a avaliac¸
˜
ao de
rendimento de motores de induc¸
˜
ao trif
´
asicos. Master’s
thesis, Escola Polit
´
ecnica da Universidade Federal da
Bahia, Salvador-BA, Brazil.
Damasceno, S. M. N., Cerqueira, J. J. F., Lima, A. C. C.,
Oliveira, A., and Jesus, R. J. (2002a). Uma pro-
posta para avaliac¸
˜
ao de rendimento de motores de
induc¸
˜
ao em cho de fbrica. In Anais do XIV Congresso
Brasileiro de Autom
´
atica, pages 1136–1141, Natal-
RN, Brazil.
Damasceno, S. M. N., Oliveira, A., Cerqueira, J. J. F., Lima,
A. C. C., Santos, E. T. F., Cunha, V. J. G., and Jesus,
R. J. (2002b). Studies about yhe methodology for the
evaluation of energetic efficiency in trifasic induction
motors on field. In Anais do V INDUSCON - Con-
ICINCO 2004 - INTELLIGENT CONTROL SYSTEMS AND OPTIMIZATION
274