Contents
D-decomposition technique is used to determine the stability/instability regions of a variable frequency induction motor. The technique is more simple, straightforward and elegant when compared to the conventional classical methods like root locus technique, Nyquist criterion and Routh-Hurwitz criterion. The machine equations are used in Park's vector notation which reduces the order of the system equation to three. The equation, however contains complex coefficients. The linearised model based on small displacements is used in the stability analysis to investigate the effects of variation of machine parameters such as stator and rotor resistances, leakage reactances etc. on the stability regions of the motor.
Übersicht
Zur Bestimmung der Stabilitätsgrenzen eines mit variabler Frequenz gespeisten Asynchronmotors wird die Methode derD-Zerlegung verwendet. Diese zeichnet sich gegenüber dem klassischen Verfahren wie dem Wurzelortsverfahren, dem Nyquist-Kriterium und dem Routh-Hurwitz-Kriterium durch Einfachheit und Direktheit aus. Infolge der Verwendung der Parkschen Transformierten stellen sich die Spannungsgleichungen der Maschine lediglich als System dritter Ordnung, jedoch mit komplexen Koeffizienten dar. Das Modell wird für kleine Abweichungen linearisiert; danach erfolgt die Untersuchung der Auswirkungen von Parameteränderungen, u. a. der Widerstände von Stator und Rotor sowie der Streureaktanz, auf den Stabilitätsbereich des Motors.
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Abbreviations
- f :
-
operating frequency
- fb :
-
rated frequency
- fr :
-
ratio of operating frequency to rated frequency
- H :
-
inertia constant
- i ds i qs :
-
two axis components of stator currents
- i s :
-
Park's vector of stator currents
- i dr ,i qr :
-
two axis currents of rotor currents
- i r :
-
Park's vector of rotor currents
- J :
-
moment of inertia
- K :
-
gain constantP/J
- l :
-
a parameter
- L s ,L r :
-
self inductances of stator and rotor respectively
- L m :
-
mutaual inductance
- P :
-
pairs of poles
- p :
-
differential operator d/dt
- R s ,R r :
-
stator and rotor resistances per phase respectively
- T d ,T L :
-
electromagnetic torque developed and load torque respectively
- u ds ,u qs :
-
two axis components of stator voltages
- u s :
-
Park's vector of stator voltages
- u dr ,u qr :
-
two axis components of rotor voltages
- u r :
-
Park's vector of rotor voltages
- ψds, ψqs :
-
two axis components of stator flux linkages
- ψs :
-
Park's vector of stator flux linkages
- ψdr, ψqr :
-
two axis components of rotor flux linkages
- ψr :
-
Park's vector of rotor flux linkages
- ωs :
-
synchronous angular velocity
- ωr :
-
rotor angular velocity
- ωr0 :
-
rotor angular velocity at an operating point
- Ω:
-
angular frequency used in the frequency domain plotting
- σ:
-
leakage coefficient 1−L 2 m /(L s L r )
References
Rogers, G. J.: Linearised analysis of induction motor transients. Proc. IEE 12 (1965) 1917–1926
Nelson, R. H.; Lipo, T. A.; Krause, P. C.: Stability analysis of a symmetrical induction machine. IEEE Trans. Power App. Syst., PAS 88 (1969) 1710–1717
Bedford, R. E.; Padhye, S. S.: Computational techniques in determining stability limits of inverter-fed induction motor, J. Inst. Eng. (India) (1975)
Jordan, H.; Müller, J.; Seinsch, O. H.: Über elektromagnetische und mechanische Ausgleichvorgänge bei Drehstromantrieben. Wiss. Ber. AEG Telefunken 52 (1979) 263–270
Jordan, H.; Kulig, T. S.: Kopplung elektromagnetischer und mechanischer Systeme in Elektroantrieben, Teil 2. Dynamisches Verhalten von Asynchronmaschinen, Siemens Forsch. Entwicklungsber. 11 (1982) 133–138
Lawrenson, P. J.; Bowes, S. R.: Generalisation ofD-decomposition techique. Proc. IEE 116 (1969) 1463–1470
Lawrenson, P. J.; Bowes, S. R.; Stephenson, J. M.: Efficient application ofD-decomposition technique to determine stability boundaries for multiparameter system, with particular reference to induction machines. Electron Lett. 4 (1968) 435–437
Lawrenson, P. J.; Bowes, S. R.: Stability of reluctance motors. Proc. IEE 118 (1971) 356–369
Novotny, D. W.: Steady state performance of inverterfed induction machines by means of time domain complex variables. IEEE Trans. Power App. Syst., PAS 95 (1976) 927–935
Subrahmanyam, V.; Subbarayudu, D.; Rao, M. V. C.: Analysis of inverter-fed induction motor via state transition signal flow graph technique. Proc. IEE 124 (1976) 259–260
Subrahmanyam, V.; Subbarayudu, D.: Steady state analysis of an induction motor fed from a current source inverter using complex state (Park's) vector. Proc IEE 126 (1979)
Lipo, T. A.; Cornell, E. P.: State variable steady state analysis of a current controlled induction motor drive. Conf. Rec. IEEE IAS (1975)
Charlton, W.: Matrix methods for the steady state analysis of induction motors. Proc. IEE 120 (1973) 363–364
Kovacs, K. P.; Racz, I.: Transiente Vorgänge in Wechselstrommaschinen. Ungar. Akad. Wiss., Budapest 1959
Neimark Yu, I.: Determination of values of parameters for which an automatic control system is stable. Autom. Telech. (1948) 190–203
Aizermann M. A.: Theory of automatic control. London: Pergamon press 1961
Mellitt, B.: The ANSI Fortran Program DDC2 forD-decomposition. Int. Commun., Dept. Electr. Electron. Eng., Univ. Birmingham
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Mwandosya, M.J., Subrahmanyam, V. & Mohamed, M.R. Stability analysis of a variable frequency induction motor usingD-decomposition method. Archiv f. Elektrotechnik 68, 345–353 (1985). https://doi.org/10.1007/BF01573585
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DOI: https://doi.org/10.1007/BF01573585