A. Petrovas

Bio: A. Petrovas is an academic researcher from Vilnius Gediminas Technical University. The author has contributed to research in topics: Induction motor & Stationary Reference Frame. The author has an hindex of 5, co-authored 20 publications receiving 60 citations.

New Model of Linear Induction Drive

Abstract: The article deals with mathematical model of linear induction drive and a developed Simulink model based on that. Developed model gives possibility to investigate transients of electric drives with rotating and linear induction motors at balanced and unbalanced supply voltage and at equal or distinct parameters of phase windings during starting process of motor with load or no-load. Derived formula to calculate developed force or torque is presented. Model of linear induction motor is developed as entity of objects corresponding to proper parts of motor: model of winding object, model of mechanical part object and model of electromechanical part object. Analysed dependencies between mechanical quantities in both rotating and linear motor used to develop model, Calculated results: force developed by linear induction motor, speed, currents of all phase windings of inductor and secondary and other parameters are obtained in form of graphs. Ill. 5, bibl. 13 ( in English; summaries in Lithuanian, English and Russian).

Research of Six-Phase Induction Motor Windings

Abstract: 1 Abstract—Advantages of multi-phase motors raise interest in its construction. The article deals with elaboration of schemes of six-phase induction motor winding, calculation and analysis of magnetomotive forces and comparison of two type six phase motor windings: concentrated double layer full pitch coil six-phase winding and short pitch coil six-phase winding.

Model of Vector Controlled Induction Drive

Abstract: 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.

Modelling of Frequency Controlled Induction Drive with Ventilator Type Load

Abstract: The great number of induction motors, controlled by frequency converters, is employed in pumps, fans and blowers Their operation develops ventilator load of the motor For matching dynamic characteristics of motor, load and converter, Simulink model of frequency controlled drive with smooth starting was developed and simulation results were analyzed Simulation results were compared with experimental ones Investigation of transients in the system with scalar control indicates good matching experimental and simulation results Average torque value during starting at no load approximately is constant at assumed acceleration 600 rpm/s The maximum torque and current values at beginning of starting do not exceed rated those Simulation of the drive with ventilator load at smooth starting and chosen ramp indicates the maximum torque value not exceeding rated that at the beginning of the starting transients Afterwards the torque rises as the load increases with speed square Steady-state speed error corresponds to 10℅ in the open loop system For greater accuracy closed loop control system with speed feedback or vector control systems should be used Ill 7, bibl 5 (in English; abstracts in English, Russian and Lithuanian)

Low-Voltage Low-Power Integrable CMOS Circuit Implementation of Integer- and Fractional–Order FitzHugh–Nagumo Neuron Model

Abstract: The low-voltage low-power sinh-domain (SD) implementations of integer- and fractional-order FitzHugh–Nagumo (FHN) neuron model have been introduced in this paper. Besides, the effect of fractional-orders on the external excitation current and dynamics of the neuron has been examined in this paper. The proposed SD designs of FHN neuron model have the benefits of: 1) low-voltage operation; 2) integrability, due to resistor-less design and the employment of only grounded components; 3) electronic tunability of performance parameters; and 4) low-power implementation due to the inherent properties of SD technique. HSPICE simulator tool and Taiwan Semiconductor Manufacturing Company, Hsinchu, Taiwan 130-nm CMOS process was used to evaluate and verify the correct functioning of the model. In addition, to experimentally verify the operation of the proposed fractional-order FHN neuron model, field-programmable analog array (FPAA) implementation of the model has been presented, and the proper functioning of the model has been verified. To the best of the authors’ knowledge, this is the first paper that describes the electronic realization of the fractional-order FHN neuron model. In addition, it is the first time that the FPAA implementation of any fractional-order neuron model has been presented.

Improving the Performance of a 1-MW Induction Machine by Optimally Shifting From a Three-Phase to a Six-Phase Machine Design by Rearranging the Coil Connections

Abstract: It is well known that multiphase machines exhibit the better performance (efficiency, torque density, fault tolerance, etc.) than three-phase machines. From the manufacturing point of view, it is interesting to have the possibility of improving a machine design by just conducting minor changes in the production process. In this regard, six-phase machines emerge as the natural choice to improve a design without modifying the active parts. This article presents an optimal procedure to shift from a three-phase to a six-phase induction motor design by just rearranging the coil connections. By starting from a three-phase winding design, different six-phase winding arrangements are analyzed. A methodology to define all the possible six-phase winding arrangements is presented. Discard criteria based on balanced radial forces and impedances are defined. Afterward, selected winding candidates are compared in terms of analytical calculations and later on, based on finite element (FE) simulations for a 690 V, 1-MW induction machine design. Different possible configurations are evaluated in terms of stator Joule losses, torque ripple, power factor, and electromagnetic efficiency both under healthy and faulted inverter conditions. Finally, a six-phase machine prototype is tested in order to verify the improvement in machine characteristics, thus validating the proposed method.

Hardware design of LIF with Latency neuron model with memristive STDP synapses

Abstract: In this paper, the hardware implementation of a neuromorphic system is presented. This system is composed of a Leaky Integrate-and-Fire with Latency (LIFL) neuron and a Spike-Timing Dependent Plasticity (STDP) synapse. LIFL neuron model allows to encode more information than the common Integrate-and-Fire models, typically considered for neuromorphic implementations. In our system LIFL neuron is implemented using CMOS circuits while memristor is used for the implementation of the STDP synapse. A description of the entire circuit is provided. Finally, the capabilities of the proposed architecture have been evaluated by simulating a motif composed of three neurons and two synapses. The simulation results confirm the validity of the proposed system and its suitability for the design of more complex spiking neural networks