INDIRECT-FIELD-ORIENTATED CONTROL OF AN ASYNCHRONOUS GENERATOR WITH ROTOR-RESISTANCE ADAPTATION BASED ON A REFERENCE MODEL Pedro Luis Roncero S´ anchez * Aurelio Garc´ ıa Cerrada ** Vicente Feliu Batlle * * Departamento Ingenier´ ıa El´ ectrica, Electr´ onica y Autom´ atica. UCLM. Campus universitario s/n, 13071 Ciudad Real, Spain ** E.T.S. de Ingenier´ ıa (ICAI), Universidad Pontificia Comillas, Alberto Aguilera 23, 28015 Madrid, Spain Abstract: This paper studies in detail a method for rotor-resistance adaptation for indirect-field orientated control of induction generators based on the reactive-power reference model. First of all, it will be shown how the adaptation procedure can be made independent of stator frequency and load torque. Secondly, the stability of the adaptation procedure will be demonstrated rigorously by means of Lyapunov theorem. Simulation results using data from two different machines will be presented to validate the main contributions. Finally, the sensitivity of the algorithm to errors in other machine parameters will be investigated. Keywords: Field-Orientated Control, Induction Motors, MRAS 1. INTRODUCTION Field-orientated control of induction motors has made it possible to extend the use of induction machines in high performance applications. Direct-field-orientated control (DFOC) includes a closed-loop rotor-flux controller and requires the calculation of rotor-flux modulus and po- sition. This is the standard solution for high- performance drives but requires complicated al- gorithms. Indirect-field-orientated control (IFOC) does not have a closed-loop rotor-flux controller and only requires the angular position of the rotor-flux vector which is calculated integrating the vector angular speed (Murphy and Turnbull, 1988). This can be computed using the rotor speed and the stator-current measurement. IFOC is a very simple and, therefore worth-to-be-considered solution in many applications. However, the cal- culation of the angular speed of the rotor flux is very sensitive to errors in rotor resistance which changes widely with temperature. Several algorithms to estimate the rotor resistance have been presented in the literature. Those based on Model Reference Adaptive Systems (MRAS) are particularly well suited for IFOC systems (Rowan et al., 1991). Typically: a) Torque Reference Model . The torque refer- ence model uses the torque equation to adapt the rotor resistance (Lorenz and Lawson, 1990). The adaptation can be utilised even during transient torque conditions. However, there is the need to know the stator resistance (variable with temperature) and L 2 M /L R , where L M and L R are the magnetizing induc- tance and the rotor inductance, respectively. Although the implementation of this method is analysed in (Lorenz and Lawson, 1990), the convergence is not studied in detail. Copyright © 2002 IFAC 15th Triennial World Congress, Barcelona, Spain