Fuzzy learning enhananced speed control of indirect field oriented drive aplative hysteresis band current controller

مقدم أطروحة جامعية

Hammadi, Amjad Jalil

الجامعة

الجامعة التكنولوجية

الكلية

-

القسم الأكاديمي

قسم الهندسة الكهربائية

دولة الجامعة

العراق

الدرجة العلمية

دكتوراه

تاريخ الدرجة العلمية

2006

الملخص الإنجليزي

Field orientation control (FOC) methods of an induction machine achieve decoupled torque and flux dynamics leading to independent control of torque and flux as for separately excited DC motor, but they are sensitive to motor parameter variations.

The present work selected the indirect field orientation control (IFOC) as an effective method for eliminating the coupling effect.

The results showed how well the drive performance has been improved by this control strategy.

However, to which extent the control strategy can perform the decoupling relies on the accuracy of the slip frequency calculation, which depends on the rotor time constant that varies continuously according to the operational conditions and, then, the coupling effect may again arise.

To compensate such parameter variations in the drive, a proportional integral derivative PI controller is firstly candidate in the outer speed loop of IFOC drive to generate a command current, directly proportional to the required torque.

However, the results showed that this fixed parameter controller is not an intelligent controller and changes in rotor time constant will degrade the speed performance.

As an intelligent control technology', fuzzy logic control (FLC) is replaced by PI controller and It has been shown that a properly designed conventional fuzzy controller outperforms (PI) controllers.

However, the performance may still be unsatisfactory when rotor time constant varies too much.

A fuzzy model reference learning control (FMRLC) technique is applied in an IFOC IM drive, such that the machine can follow a reference model (an ideal field oriented machine) to achieve desired speed performance.

This learning control algorithm can intelligently synthesize a direct fuzzy controller for the plant, and later tune it on-line if there are disturbances or / and plant variations An FMRLC scheme has been designed for an IFO induction machine drive system and the results of computer simulation showed that a better performance of the IFO drive system is attained with this controller, as compared to PI and fuzzy logic controllers, in terms of overshoot, steady-state error, load disturbance rejection and variable speed tracking.

The results showed that the FMRLC makes the speed control of the IFO drive robust against motor parameter variations.

Hysteresis current controller is one of the simplest techniques used to control the magnitude and phase of AC currents of high performance drive systems.

However, conventional fixed band hysteresis controller has a variable switching frequency throughout the fundamental period.

An adaptive hysteresis-band current controller (HBCC) comes as a solution to reach an optima! ripple current.

التخصصات الرئيسية

الهندسة الميكانيكية

الموضوعات

• الحوسبة

• APA
• MLA
• AMA

لغة النص

الإنجليزية

نوع البيانات

رسائل جامعية

رقم السجل

BIM-305613