Thomas Devos

Antiwindup Design for Induction Motor Control in the Field Weakening Domain

Operation of induction machines in the high-speed and/or high-torque range requires field-weakening to comply with voltage and current physical limitations. This paper presents an anti-windup approach to this problem: rather than developing an ad-hoc field weakening strategy in the high-speed region, we equip an unconstrained vector-control design with an anti-windup module that automatically adjusts the current and flux set-points so that voltage and current constraints are satisfied at every operating point. The anti-windup module includes a feedforward modification of the set point aimed at maximizing the available torque in steady-state and a feedback modification of the controller based on an internal model-based antiwindup scheme. This paper includes a complete stability analysis of the proposed solution and presents encouraging experimental results on an industrial drive.

Robustness Analysis of a Position Observer for Surface{Mount Permanent Magnet Synchronous Motors vis{ a{vis Rotor Saliency

Abstract A gradient descent-based nonlinear observer for surface-mount permanent magnet synchronous motors (PMSMs) with remarkable stability properties was recently proposed in [7]. A key assumption for the derivation of the observer is the absence of rotor saliency, which is the case in surface-mount PMSMs. A question of great practical interest is to assess the performance of the observer in the presence of saliency. This is the topic of study of the present paper. It is shown that the robustness of the observer is fully determined by the sinusoidal steady-state values of the currents, providing some guidelines for the selection of their reference values to ensure good position estimation.

Robustness analysis of position observers for permanent magnet synchronous motors vis-à-vis rotor saliency

A gradient descent-based nonlinear observer for surface-mount permanent magnet synchronous motors (PMSMs) with remarkable stability properties was recently proposed in [7]. A key assumption for the derivation of the observer is the absence of rotor saliency, which is the case in surface-mount PMSMs. Practically, PMSMs have saliencies from low level for surface-mount PMSMs to high level for internal-mount PMSMs. A question of great practical interest is to firstly assess the performance of the observer in the presence of saliency, and secondly to propose way of enhancement to take this effect into account. This is the topic of study of the present paper. We show in simulation the performance of the different observers.