Roma Rinkeviciene

Dynamic Models of Asymmetric Induction Drive

Some types of induction motors such as linear induction motors because their constructional properties are asymmetrical as well as some kinds of revolving motors, designed for special purposes also are characterized by asymmetric magnetic and electric circuits. The article presents dynamic mathematical models of asymmetric induction drive with Y connected windings with neutral wire and without it, as well as with Delta connected windings. Calculated starting transients of linear motor speed, force, currents and consumed power are presented and analyzed. The greater asymmetry of motor currents leads to increase considered variables.

Model of Vector Controlled Induction Drive

The paper presents the model of vector controlled induction motor. Induction motor model is carried out in reference frame, fixed on stator. Elaborated model of the drive is suitable for investigation dynamics because output signals appear as real currents, flux linkages and other variables. Vector control law model is implemented for variables in synchronous reference frame; therefore controller operates with transformed variables. Structure of designed model reflects the real variable speed drive. Model of vector controlled induction drive comprise model of induction motor, feedback signals and blocks as well as speed and flux reference blocks and controllers for producing motor supply signals. Feedback blocks are used for calculation stator current vector in the rotor flux linkage reference frame. For flux and speed control are designed lag controllers. Between advantages of that model is additional simulation of current channel law.

Design of Observer for Direct Current Drive

Control theory proposes to apply observers in systems with uncertain plant parameters. Observers can be used for calculation of feedback gains and getting desired, even strictly determined response requirements. The paper considers design of controller for direct current drive. As state space variables are chosen armature current and angular speed of motor. Mathematical model of the motor, operating with load which is assumed as disturbance, is elaborated. Full order Luenberg observer is designed according to desired characteristic equation of system. The results of simulation are presented and discussed.

Properties of Linear Induction Drive of Actuating Systems

Article deals with small power low speed linear induction drives of actuating systems. It is proved that current of these linear induction motors (LIM) does not depend on slip, transients of current are short and dynamical amplitudes are small. There are presented expressions, allowing to calculate the steady state and dynamic characteristics when the drive is controlled by changing supply voltage frequency.

Dynamics of Dust Explosion Localizing System

The problem of dust explosion in corn processing enterprises is analyzed. System for localizing of dust explosions with dampers driven by linear induction motors (LIM) is considered. The paper presents the developed mathematical and computer models of a damper drive together with results of simulations.