Bernard de Fornel

Power distribution law in a Doubly Fed Induction Machine

The paper deals with a Doubly Fed Induction Machine (DFIM). It presents a study of an active power distribution law between stator and rotor sides. The DFIM is supplied by two voltages PWM inverters in stator and rotor. The power distribution law imposes a relation between rotoric and statoric pulsations. Due to this relation, a new variation structure of the DFIM speed control is presented. The four quadrants working are considered. Simulation results under Matlab-Simulink illustrate the performances of the power distribution law.

Non-Linear Control with Adaptive Observer for the Sensorless Induction Speed Drives

Abstract In the framework of the sensorless non-linear control of a PWM fed induction motor drive, an original strategy is proposed. The latter is an association of the control based on the Inputs-Outputs (I/O) system lineatharion [2], with a MRAS (Model Reference Adaptive System) state observer [7]. The observer design and synthesis uses Popov’s hyper-stability theory. For the sensorless drive, the rotation speed adaptive law is proposed [5]. All control and observation parameters are determined analytically. The precise simulations of the global system allow to testing the basic Operation functions of this drive and especially the good behaviour at very low rotation speed. Significant experimental results are discussed to illustrate the dynamic performances of this induction motor drive in the four quadrants of the torque – speed plane.

INFLUENCE OF QUANTIZATION EFFECTS AND PARAMETERS DEVIATIONS ON THE PERFORMANCE OF A FIELD ORIENTED ASYNCHRONOUS DRIVE

SUMMARY During the last few years, the control of induction machine by the field orientation method has become the preferred technique which yields very good performances. This method allows to define the dynamic structure of an induction machine which is similar to that of D.C machine. This is obtained by controlling the angular position of the rotor flux so that the flux and torque can be decoupled. The process to be controlled is composed of an autopiloted induction machine fed by a voltage inverter. In this paper the authors study the influence of different problems due to the numerical processing of informations by the computer on the system performances. These problems, usually neglected, are closely related to the performances and the dynamic of the system to be controlled. It should be noted that the vector control method is very sensitive to the precision with which the angular position of the rotor flux has been determined. The use of a computer in the regulation chain implies a sampling time an...

Comparison of Cartesian vector control and polar vector control for induction motor drives

The performances of a vector control in the stator fixed frame are studied. This so called cartesian structure is compared with a classical vector control, which uses the flux polar coordinates. This cartesian control avoids the phase determination problem, but needs more complex controllers.