Commande de haute performance sans capteur d'une machine asynchronen /

Abstract

Induction machine, when driven by a field oriented controller behaves like a separately excited dc machine, where torque and flux are naturally decoupled and are controlled independently; and this control strategy allows high performance to be achieved from it.However, conventional vector controlled induction motor drive has the disadvantage of requiring speed sensor which increases the cost and complexity of the drive system.Moreover, drive performance is affected by rotor resistance, whose unknown variation during the operation causes incorrect decoupling of flux and torque which leads to deterioration of drive performance. This thesis focusses on the development of a high performance sensorless induction motor drive. Control of the drive is done in rotor flux coordinates which allows natural decoupling of flux and torque producing components of stator current space vector. Sensorless control of the drive system is achieved by developing rotor flux and speed estimation algorithms using only the measurable stator terminal quantities: the current and voltage. The state and parameter estimation problem is looked into as a question of proper mathematical modeling of the machine in an appropriate reference frame, which along with proper choice of states, enables us to develop an estimation algorithm capable of accurate estimation.In this work a two pronged approach is adopted to achieve the research objective. First approach is based on the fact that dynamics of rotor speed is much slower than that of electrical states of the machine. Hence, the time derivative of rotor speed can be conveniently equated to zero in the machine model used for implementing the estimation

Adaptive Dynamic Control Based Optimization of Renewable Energy Resources for Grid-Tied Microgrids

“…Li-ion rechargeable batteries have been considered in the proposed system to charge and discharge according to the working scenario. Battery capacity (Ah) and battery power (kWh) can be calculated through Equations ( 14) and (15).…”

“…In order to address the concerns about the microgrid EMS problem, the authors of [11] used the pumped storage unit and DR programme in a novel stochastics optimization framework. In [12][13][14][15][16], the authors have presented an overview of contemporary innovations for the use of microgrid storage and DR operations. In [17][18][19], the authors analyzed power optimization in hybrid microgrids based on the formulation and optimization of spinning reserves.…”

Real-time implementation of SVPWM-sensorless vector control of induction motor using an extended Kalman filter

“…Induction machine control for high performance drive applications now adheres to the field oriented control (FOC) or vector control developed by Blaschke [3] and Hasse [4]. Induction motor control based on the field orientation concept provides good performance in variable speed applications [5]- [7], as well as control properties resembling a separately excited dc machine. Although the stator current space vector can be oriented along the mutual flux, stator flux, or rotor flux, doing so alone results in a natural decoupling between the torque and flux-producing components of the stator current space vector.…”