Contributions à l'étude de la machine à commutation électronique

Doctorat en sciences appliquées -- UCL, 197

[Contributions to the study of the electronic communication motor. I. Theoretical and experimental study of the controlled rectifier generator]

This paper presents an application of the commutation circuit theory to the study of the controlled rectifier generator: that is the association of a synchronous machine with a controlled rectifier where the triggering of thyristors is controlled by a sensor of the relative position field/armature. The three-phase generator associated with a full-wave bridge rectifier is especially studied. The analysis shows several possible operation modes: the controlled rectifier operation mode, the uncontrolled rectifier operation mode and the commutation failure causing an alternator operation mode. The developed model, suitable for transient analysis, could be used for the study of controlled rectifying and the behaviour of the electronic commutation DC motor (synchronous type).Francai

From smart actuators to smart sensors position and speed measurements using digital encoder.

Electrical actuators are generally applied in the field of robotics used to control speed or position using a numerical controller; digital sensors are then preferred because of their compatibility with the controller. Binary or digital encoders, generally of the optical type, are a good choice, since they provide a position information in a digital form which allows speed calculation by numerical derivation. The aim of this paper is to define the application limits of these digital encoders considering their correct use, taking into account an adequate signal processing but also particular application conditions

From smart sensors to smart actuators: application of digital encoders for position and speed measurements in numerical control systems.

Electrical actuators are generally applied in the field of robotics to control speed or position using a numerical control system; digital sensors are then preferred because of their compatibility with the control system. Binary or digital encoders, generally of the optical type, are well adapted, since they provide a position information in a digital form which allows speed calculation by numerical derivation. The aim of this paper is to define the application limits of these digital encoders considering their optimal use, taking into account an adequate signal processing but also particular application conditions

[Theoretical and experimental study of the generator- rectifier. II. Study of the generator-rectifier in transient conditions]

For pt. I see ibid., 61-70 (1972). This paper presents an application of the commutation circuits theory to the transient analysis of the synchronous machine with rectified output. The response of a three- phase generator with a bridge rectifier to a sudden load or field variation is studied. The analysis shows the unbalancing of the three phases during large transients and provides a model suitable for automatic control applications.Francai

Fuzzy logic based field orientation in an indirect FOC strategy of an induction actuator

The aim of this paper is to propose a modification in the classical indirect field oriented control strategy to reduce its sensitivity to electrical parameter uncertainties. This modification is based on a theoretical sensitivity analysis and introduces in the control strategy a very simple fuzzy logic block to ensure the field orientation. (C) 1998 IMACS/Elsevier Science B.V

[Simplified and robust digital control of low power induction actuators]

High performance motion control with AC actuators needs complex control strategies. The control strategies lead frequently to algorithms requiring powerful microprocessors for their digital implementation. In a previous paper published in the Journal de Physique III, we evolved an approach for the control of small power permanent magnet synchronous actuators which allows one to design and to implement control algorithms requiring reduced computation power, while maintaining satisfactory static and dynamic performance and a good insensitivity to perturbations and parameter uncertainties. In this paper, we extend this approach to the control of small power induction actuators.Francai