Improvement of Indirect Field-Oriented Vector Control in Induction Motors

نوع: Type: Thesis

مقطع: Segment: masters

عنوان: Title: Improvement of Indirect Field-Oriented Vector Control in Induction Motors

ارائه دهنده: Provider: mohammad safari

اساتید راهنما: Supervisors: Dr. Mohammad Hassan Moradi

اساتید مشاور: Advisory Professors: Dr. Alireza Jahangiri

اساتید ممتحن یا داور: Examining professors or referees: Dr. Mohammad Mehdi Shahbazi – Dr. Mohsen Hassan Babaei Nozadian

زمان و تاریخ ارائه: Time and date of presentation: 2026

مکان ارائه: Place of presentation: 34

چکیده: Abstract: Precise control of torque and speed in induction motors has always been a fundamental challenge in electric drives due to the motor's nonlinear nature and the strong coupling between flux and torque. Conventional methods—such as Indirect Field-Oriented Control (IFOC) and Direct Torque Control (DTC)—rely on complex flux and torque estimators; consequently, their performance degrades significantly under conditions of parameter uncertainty and at low speeds. In this thesis, an indirect active and reactive power control method is proposed to enhance induction motor drive performance, and the IFOC structure is modified accordingly. In this approach, rather than estimating flux and torque, instantaneous active and reactive powers are calculated using measured voltage and current and compared against reference values. PI power controllers generate reference currents aligned with the stator flux, while hysteresis current controllers—working in conjunction with a switching table—determine the inverter's switching states. The primary advantage of the proposed method is the complete elimination of flux and torque estimators, resulting in significantly improved robustness against motor parameter variations and enhanced performance across various speeds. Additional benefits include a simplified control scheme, the elimination of complex calculations and extra sensors, and rapid dynamic response. To validate the proposed method's effectiveness, simulation results obtained in MATLAB—covering a wide speed range and accounting for both accurate and inaccurate motor parameter assumptions—are presented and compared with the classical IFOC method. The results demonstrate the proposed method's clear superiority in terms of robustness, dynamic response quality, and low-speed performance.