Damien Grenier

Experimental nonlinear torque control of a permanent-magnet synchronous motor using saliency

In this paper, a new nonlinear control strategy is proposed for a permanent-magnet salient-pole synchronous motor. This control strategy simultaneously achieves accurate torque control and copper losses minimization without recurring to an internal current loop nor to any feedforward compensation. It takes advantage of the rotor saliency by allowing the current (i/sub d/) to have nonzero values. This, in turn, allows us to increase the power factor of the machine and to raise the maximum admissible torque. We apply input-output linearization techniques where the inputs are the stator voltages and the outputs are the torque and a judiciously chosen new output. This new output insures a well-defined relative degree and is linked to the copper losses in such a way that, when forced to zero, it leads to maximum machine efficiency. The performance of our nonlinear controller is demonstrated by a real-time implementation using a digital signal processor (DSP) chip on a permanent-magnet salient-pole synchronous motor with sinusoidal flux distribution. The results are compared to the ones obtained with a scheme which forces the i/sub d/ current to zero.

Development of a Spherical Induction Motor With Two Degrees of Freedom

This paper reports on the development of a spherical actuator with two actuated degrees of freedom (DOFs). The electromechanical conversion principle is that of an induction motor. The paper first discusses possibilities of adapting the actuator to a spherical rotor actuated with an unlimited angular range along two DOFs. These concepts are then characterized and compared by analytical and numerical modeling, and the final shape of the actuator, composed of a two-layer rotor with teeth surrounded by five inductors, is described. A prototype has been built, and its performance, in terms of characteristic torque-speed and efficiency, has been measured.

Two-degree-of-freedom spherical actuator for Omnimobile ROBOT

This paper deals with the design of a two-degree-of-freedom spherical electrical actuator for mobile robotic applications. It presents the different steps involved in this design, namely the choice of the actuation principle, the modelling of the motor (including the electromechanical) the sizing and the manufacture of a first prototype.

Design of PM Motor Drive Course and DSP Based Robot Traction System Laboratory

This paper presents a part of North Africa/Europe collaboration results in education to develop project-oriented courses in power electronics and motor drive field. The course aims to teach Permanent Magnet motor drives close to a real world project of significant size and depth so as to be motivational, namely mobile robot project. Particular skills, student will acquire, are those relative to the detailed design and implementation of PM motor controllers in DSP based rapid prototyping environment. Simulation work is completed using graphical modeling tools in Simulink/Plecs, while real-time implementation is achieved by means of eZdspF2812 board and Simulink/TI C2000 Embedded Target tools. This flexible development environment fit the robot traction system very well and provides exactly the functionality necessary for an efficient PM motor drives teaching as demonstrated by a set of simulation and experiments.

Direct torque control of PM AC motor with non-sinusoidal flux distribution using state-feedback linearization techniques

In this paper, the authors present a direct torque control scheme for a permanent-magnet (PM) AC motor. For this purpose, state feedback input-output linearization techniques are used with a systematic way of selecting outputs in such a way that not only the torque-voltage (or speed-voltage and position-voltage if necessary) relationship is linearized but a physical criterion is optimized (the minimization of copper losses for example). This strategy can be applied to various types of motors, such as brushless DC motors and PM stepper motors, and can also be seen as method to extend the Parks transformation. Simulations show the high performances of the proposed direct torque control scheme.

Hybrid magnetic equivalent circuit – finite element modelling of transformer fed electrical machines

This paper deals with the modelling of transformer supply in the two‐dimensional (2D) finite element (FE) simulation of rotating electrical machines. Three different transformer models are compared. The reference one is based on two 2D FE models, considering a cross‐section either parallel or perpendicular to the laminations of the magnetic core. The parameters of the two other transformer models, a magnetic equivalent circuit and an electrical equivalent circuit, can be derived from the reference model. Particular attention is paid to some common features of the transformer models, e.g. with regard to the inclusion of iron losses. The three models are used in the 2D FE simulation of the steady‐state load operation and the starting from stand‐still of an induction motor.

Electrical Actuation Systems with AC Motors an Example of Complex Automatic Control

Abstract Digitally controlled actuation systems with VSI fed AC motors are examples of complex hybrid systems combining digital and continuous variables : - synchronous or induction motors are non linear multivariable subsystems; - the control amplifier consisting in a power electronic converter feeding the motor can only produce a limited number of control vectors from which control variables are obtained by an appropriate sequence in order to follow the references generated by the digital regulator. It will be shown how the discrete and non linear characteristics of these systems can be taken into account even if the control is fully digital.

Looking into the implementation of AC motor control on a fixed point processor

The purposes of this paper are first to show that fixed point processors can meet the needs of high performances, and even complex AC motor control algorithms; and then to present a way, well adapted for the normalized fixed point structure, in which voltages can be rounded in the d-q frame, in order to avoid overflows in the a-b-c frame, while keeping as much dynamic as possible.