Petru Livinti - Academia.edu (original) (raw)

Papers by Petru Livinti

The driving system of the industrial robot RBH2 is hydraulic. It is composed of a hydraulic unit ... more The driving system of the industrial robot RBH2 is hydraulic. It is composed of a hydraulic unit with a drive power KW and 12 solenoid valves. The control system of the industrial robot is composed of: a) TWIDO programmable automation made by the firm Schneider, b) interface for controlling the solenoid valves, c) supply source for solenoid valves, d) solenoid valves, e) position sensors. The TWIDO programmable logic controller (PLC) has the following features: 20 numerical inputs, 16 numerical outputs. The numerical signal from the position sensors of the industrial robots are taken over programmable automation. The numerical signals for controlling the solenoid valves are transmitted from programmable automation to the solenoid valve control interface. Depending on the technological process where the robot is used a control program for the solenoid valves of the robot driving circuit is issued. For each control algorithm of the industrial robot required by the technological proces...

This paper is presenting a control system equipped with programmable automation TWIDO for star-de... more This paper is presenting a control system equipped with programmable automation TWIDO for star-delta starting of three-phase asynchronous motors with short circuited rotor. For programming the TWIDO programmable logic controller (PLC), the program TWIDO-SOFT.EXE is used. The control system is composed of: TWIDO programmable logic controller, high voltage contactor for the asynchronous motor supply, interface for controlling the contactor coils, control buttons and signal circuits. The star- delta automatic start-up of three-phase asynchronous motor is provided.

Sustainability , 2021

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Digital Technologies and Applications, 2021

This paper presents a non-invasive procedure to detect inter-turn short circuit faults in the sta... more This paper presents a non-invasive procedure to detect inter-turn short circuit faults in the stator windings of AC electrical machines. It proposes the use of the stray external magnetic field measured in the vicinity of the machine to determine stator faults. The originality introduced by this procedure is the analysis method presented in the paper, which when compared to usual diagnosis methods, does not require any data on the healthy state of the machine. The procedure uses the magnetic unbalance created by the rotor poles and the load variation in faulty cases. The presented method can be applied to induction and synchronous machines used as a motor or generator. It is based on the variation of sensitive spectral lines obtained from the external magnetic field when the load changes. Analytical relationships are developed in the paper to justify the proposed method and to explain the physical phenomenon. To illustrate these theoretical considerations, practical experiments are ...

This paper is presenting a control system equipped with programmable automation TWIDO for stardel... more This paper is presenting a control system equipped with programmable automation TWIDO for stardelta starting of three-phase asynchronous motors with short circuited rotor. For programming the TWIDO programmable logic controller (PLC), the program TWIDO-SOFT.EXE is used. The control system is composed of: TWIDO programmable logic controller, high voltage contactor for the asynchronous motor supply, interface for controlling the contactor coils, control buttons and signal circuits. The stardelta automatic start-up of three-phase asynchronous motor is provided.

In the performance increase area of autonomous wind power stations I have worked on the modeling ... more In the performance increase area of autonomous wind power stations I have worked on the modeling three-phase asynchronous generators used in their construction as well as the design and the implementation of the synchronous generators with permanent supermagnets that can be used in their construction. I have also developed control algorithms in real-time for priority and non priority loads connected to the output terminals of asynchronous generators in the componence of the low-power wind power stations. I have also developed an intelligent system for real time energy management of the energy produced by wind power stations. Concerning the performance increase in the area of photovoltaic systems for electricity production I worked for the photovoltaic systems modeling and the development of the control algorithms of fophotovoltaic systems with data acquisition and control board CompactRIO 9074. In this area I have developed control algorithms in the programming LabVIEW environment f...

This work presents an experimental stand for the study of a power electronics control system to l... more This work presents an experimental stand for the study of a power electronics control system to locate and track the maximum power point of a photovoltaic (PV) array to ensure efficient power transfer from the solar cells to the load under varying environmental conditions. A real-time photovoltaic solar cell measurements and a control system was developed to guarantee that the maximum power output is attained. This stand is built at the Electrical Machinery Laboratory of “Vasile Alecsandri” University of Bacau, Romania.

International Journal of Advanced and Applied Sciences, 2021

This paper was presented a comparative study on the methods of adjusting the speed of a three-pha... more This paper was presented a comparative study on the methods of adjusting the speed of a three-phase asynchronous motor with a rotor in a short circuit. For the same structure of the experimental stand used, two programs were created, implemented, and validated in LabVIEW. For the first method, the program in LabVIEW was made with the PI (proportional-integrative) controller and for the second method, the program in LabVIEW was made with the Fuzzy Logic controller. Following the analysis of the resulting graphs, it was found that the speed control system made with the fuzzy logic controller ensures an increase in its performance compared to the speed control system made with the conventional PI type controller. The indicial responses of the adjustment system of the three-phase asynchronous motor speed with PI controller or Fuzzy Logic controller have been determined in real-time by means of the experimental stand. The override of the speed adjustment system is decreased from the valu...

Journal of Energy and Power Engineering, 2021

This paper presents a comparison of the results obtained from the integration of the photovoltaic... more This paper presents a comparison of the results obtained from the integration of the photovoltaic system to the electrical grid
through the Active Power Filter. The innovative aspect of this article consists of the elaboration of 4 models in Matlab/Simulink for 4
methods of control of the Active Power Filter introduced between the photovoltaic system and the alternating current grid and the
highlighting of the performances obtained regarding the quality and quantity of electricity transferred for each control method in part.
Following the analysis of the results, it was found that by using the Indirect Control (CI) method of the Active Power Filter, the best
results are obtained THDu = 3.24%, THDi = 2.46% if the photovoltaic system produces a larger amount of energy than the nonlinear
load, and by using the methods of control of the Active Power Filter Synchronous Reference Frame (DQ) and Instantaneous Power (PQ)
the best results are obtained: THDu = 3.22%, THDi = 5.26% for the method (DQ) and THDu = 3.41%, THDi = 5.17% for the method
(PQ) if the photovoltaic system produces a smaller amount of energy than the nonlinear load.

Sustainability

This work presents a comparative study for a photovoltaic system connected to a three-phase grid ... more This work presents a comparative study for a photovoltaic system connected to a three-phase grid through a three-phase inverter controlled by a fuzzy logic controller or through a proportional-integral (PI) controller. The innovative aspect of this article consists of the elaboration of two models in MATLAB–Simulink for the photovoltaic system consisting of 40 photovoltaic panels and of the control algorithms of the three-phase inverter for each type of controller. The comparative analysis of the results obtained through simulation has established that the use of the fuzzy logic controller (for controlling the three-phase inverter) leads to transferring to the alternative current (AC) grid an electric power of 6.5 kW, whilst the use of the PI type controller leads to transferring to the AC grid an electric power of 4.6 kW under the same value of the intensity of solar radiation. The total harmonic distortion (THD) of the voltage resulting after the filtering circuit has a lower valu...

Proceedings of the 23rd International DAAAM Symposium 2012

DAAAM International Scientific Book, 2016

This work presents an electric drive system equipped with a permanent magnet D.C. servomotor supp... more This work presents an electric drive system equipped with a permanent magnet D.C. servomotor supplied from a D.C. voltage converter. For designing the speed regulator, the module criterion has been used, namely the Kessler variant. In the LabVIEW graphic programming environment an application has been conceived for real time control of the permanent magnet D.C. servomotor speed (rpm). For implementing the application in real time, a P.C. has been used, as well as a data acquisition board CompactRIO 9074 produced by National Instruments -U.S.A.

Procedia Engineering, 2015

This work presents an experimental stand for the PWM control of a DC motor used for driving a con... more This work presents an experimental stand for the PWM control of a DC motor used for driving a conveyor belt. For supplying the DC motor an H-bridge has been used that allows the reversal of the motor rotation wise. The PWM signal is generated by an ARDUINO UNO board, equipped with an Atmega 328 microcontroller. For controlling the ARDUINO UNO board, a program has been issued in the LabVIEW 2013 programming environment. The purpose of the experimental stand consists of studying the running characteristics of the conveyor belts under laboratory conditions, so that, further on, such driving systems can be implemented to industrial applications as well. Unlike other driving systems of conveyor belts, this system allows the optimization, by trials, of their running duties. The running duty of a conveyor belt may be modified by modifying the duty-cycle value of the PWM signals that controls the transistors of the H-bridge that supplies the DC motor. The PWM control of the DC motor provides the performances settled at the designing stage.

Proceedings of the 6th International Conference on Optimization of Electrical and Electronic Equipments, 1998

ABSTRACT Not Available

2012 9th International Conference on Remote Engineering and Virtual Instrumentation (REV), 2012

ABSTRACT This work present an electric drive system fitted with a three-phase asynchronous motor ... more ABSTRACT This work present an electric drive system fitted with a three-phase asynchronous motor supplied from a static frequency converter. The graphic programming environment LabVIEW is conceived for real time control of the electric drive system. For implementing this application in real time a personal computer has been used. It is equipped with a data acquisition board NI-PCI 6251 produced by National Instruments S.U.A.

Procedia Engineering, 2014

This work presents an experimental stand for the study of a three-phase synchronous generator in ... more This work presents an experimental stand for the study of a three-phase synchronous generator in reverse construction with permanent super magnets. This stand has been built at the Electrical Machinery Laboratory of "Vasile Alecsandri" University of Bacau. Synchronous generators with permanent magnets are used for producing electricity in wind power stations. A synchronous generator of normal construction is composed of two armatures: a fixed armature named stator and a moving one, named rotor; the latter is concentrically located inside the fixed armature. This experiment has used a synchronous generator with permanent super magnets in reverse construction, where the fixed armature named stator is located inside the moving armature, named rotor. With the help of the experimental stand the characteristics of the synchronous generator with permanent super magnets in reverse construction have been determined.