Volume 4, number 1, 2010: Print version and published papers:
HIGH FREQUENCY ELECTROMAGNETIC PROCESSES IN INDUCTION MOTORS SUPPLIED FROM PWM INVERTERS
Ioan ŢILEA,North University of Baia Mare
Keywords: electromagnetic interference, inverter, induction motor
Abstract: The paper presents the electromagnetic interference between induction motors and inverters when at high frequency electromagnetic process appears in induction motors having a parallel resonant effect because of parasitic capacitive coupling between windings and ground, using a numerical model in simulink and a high frequency induction motor equivalent circuit model this effect is shown.
ON DISTRIBUTED MODEL PREDICTIVE CONTROL FOR LOAD FREQUENCY PROBLEM
Cristinel COSTEA, North University of Baia Mare, ccostea@ubm.ro
Keywords: distributed control, load frequency control, multi-agent systems
Abstract: The paper discribe a multi-agent application in power systems for the problem of Load Frequency Control. The connections between subsystems are treated by each controller agent as a set of disturbance signals. Each area maintain the tie-lines power flow to specified values,based on communication between neighboring agents.
CONSIDERATIONS REGARDING ASYNCHRONOUS MOTOR ROTOR PARAMETERS DETERMINATION BY FEM
Olivian CHIVER, Liviu NEAMT, Zoltan ERDEI, Eleonora POP,North University of Baia Mare, email: olich@ubm.ro, liviu_neamt@ubm.ro, nora@ubm.ro, erdeiz@ubm.ro.
Keywords: asynchronous motor, rotor parameters, finite elements method
Abstract: The paper presents some considerations about asynchronous motor rotor parameters determination, using software based on finite elements method (FEM). For this, 2D magnetostatic and time harmonic analysis will be realized, at different frequencies, in case of a three phase asynchronous motor.
SWITCHED RELUCTANCE MOTOR OPTIMAL GEOMETRY DESIGN
Liviu NEAMŢ, Arthur DEZSI, North University of Baia Mare, Romania, Eaton Electrical Group, Romania, liviu_neamt@ubm.ro
Keywords: SRM, Finite Element Method, Design
Abstract: This paper deals with the Switched Reluctance Motor (SRM) analysis using Finite Element Method (FEM) for geometrical optimization in terms of volume ratio of torque on the rotor, the so-called specific torque. The optimization parameter is the pair: stator and rotor pole angles, which forms a crucial part of the design process.
COMPARISON BETWEEN ANALOG AND DIGITAL FILTERS
Zoltan ERDEI, Paul BORLAN and Olivian CHIVER, North University of Baia Mare, Romania, erdeiz@yahoo.com
Keywords: analog filters, digital filters, signal proccesing
Abstract: Digital signal processing(DSP) is one of the most powerful technologies and will model science and engineering in the 21st century. Revolutionary changes have already been made in different areas of research such as communications, medical imaging, radar and sonar technology, high fidelity audio signal reproducing etc. Each of these fields developed a different signal processing technology with its own algorithms, mathematics and technology, Digital filters are used in two general directions: to separate mixed signals and to restore signals that were compromised in different modes. The objective of this paper is to compare some basic digital filters versus analog filters such as low-pass, high-pass, band-pass filters. Scientists and engineers comprehend that, in comparison with analog filters, digital filters can process the same signal in real-time with broader flexibility. This understanding is considered important to instill incentive for engineers to become interested in the field of DSP. The analysis of the results will be made using dedicated libraries in MATLAB and Simulink software, such as the Signal Processing Toolbox.
AN ECONOMICAL AND TECHNICAL CASE STUDY FOR A SMALL HYDROPOWER SYSTEM
Dumitru Dan POP, Vasile Simion CRACIUN, Liviu NEAMT, Radu TIRNOVAN, Teodor VAIDA, Technical University of Cluj Napoca, dan.pop@eps.utcluj.ro, Keywords: hydropower system, RETScreen, renewable energy, turbine
Abstract: This paper presents a case study regarding the economical and technical parameters of a hydropower system for a mountain chalet – hotel. The calculations are made using RETScreen software starting from the average flow values of the considered river, and according to this, the hydro power plant equipments are chosen. In this case study the hydropower system is connected to central grid but also having its own storage backup system, part of the energy is consumed by the mountain chalet – hotel and the remaining energy is delivered to the central grid.