Mihai Rata

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The IGBT is one of most important power semiconductor device for converter applications from several hundred watts up to 2 MW. This is used only in commutation mode and combines advantages of a MOSFET's (high gate resistance) and bipolar transistor's (small collector-emitter drop at saturated condition). When we use IGBTs for converter application it's very(More)
This paper presents a study of the deforming regime generated by different light sources. We use several kinds of light bulbs: incandescent, gas discharge lamp and light-emitting diodes. For the acquisition and the analysis of voltage and current signals we use reconfigurable CompactRIO system from National Instruments. It allows real time monitoring of(More)
Designing ACS (automatic control system) in closed loop was more an art than science until the Industrial Revolution, when mathematics began to be used (for the first time in the middle of nineteenth century) in stability analysis of ACS in closed loop. Currently, the automation of industrial installations is carried out either using PLCs (Programmable(More)
In many specific laboratories the students use only a PLC simulator software, because the hardware equipment is expensive. This paper presents a solution that allows students to study both the hardware and software parts, in the laboratory works. The hardware part of solution consists in an old plotter, an adapter board, a PLC and a HMI. The software part(More)
Today, in most automatic process control applications in industry are used PID controllers. It is very important for the students to understand how work these controllers and how important it is to make an optimal tuning of these controllers. This paper presents a solution which permits to study and understand PID controllers. This solution is a closed-loop(More)
REZUMAT. Scopul acestei lucrări este de a prezenta o structura de control a poziţiei pentru motoarele asincrone bifazate. În cazul acestei metode de reglare a poziţiei, motorul asincron bifazat este conectat ca o sarcină dezechilibrată între cele trei braţe ale invertorului. Strategia de comandă urmăreşte menţinerea permanentă a unui defazaj de 90° între(More)
The three-phase squirrel-cage induction motors are mostly used in industrial drivers since they are rugged, reliable and economical. The DC bus voltage of the AC drives increases when the motor regenerates. The regenerating energy is usually released in the form of heat. A short mathematical description and the experimental results for different cases of(More)
LED lamps have many advantages in comparison with incandescent lamps, halogen lamps and compact fluorescent light lamps. Although produce harmonic pollution due to the drivers used for their power supply, they are becoming increasingly used nowadays. This paper presents a study of the harmonics from dimmable LED lamps, using reconfigurable CompactRIO(More)
In this paper, different solutions for power supply of a resistance used for the liquid heating were analyzed. The authors propose the best solution in terms of reliability, harmonic pollution of power network and precision temperature control. For this were used: the XC-CPU101 PLC, the XV102 HMI (Human Machine Interface) from EATON. The temperature control(More)