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With the increasing of non-linear loads in results show that voltage sag affects the functionality of electric power system, power quality distortion has adjustable speed drives [4]. Therefore, a good power quality become a serious issue in recent years. In paper and pulp monitoring system is essential for the paper mills in order to industries, due to presence of concentrated high power decrease the downtime and increase the efficiency. Although, non-linear loads such as electric drives, this problem is a electric drives are sensitive to voltage distortions, they are greater concern. In this paper, the impacts of power also one of the major sources of current harmonics generation quality distortions such as voltage sag and swell on the and power quality problems. Electric drives draw nonoperation of electric devices in Mazandaran Wood and sinusoidal currents from the electrical power system. The Paper Industries (MWPI) are discussed. Using the actual current harmonics passing through the impedance of the data, the effects of voltage sag on the main production power system create non-linear voltage drops and cause line motor drive is investigated. In addition, the effects of voltage distortions. Therefore, the input voltage provided to harmonics on the distribution transformers such as the distribution transformers is not pure sinusoidal. One of the increasing their losses and decreasing their life are major effects of harmonic distortions is increasing transformer analyzed.losses. In presence of harmonics, the load loss, eddy current loss, and other stray losses are increased. In addition, they Index Terms -Electrical Drive, Harmonics, Paper Mill, increase the hot spot temperature of the transformer which Power Quality, Transformer Life, Voltage Sag. results in loss of life. Furthermore, if voltage harmonics level is more than standard, audio noise and no load loss will also be

This paper proposes an interleaved zero-voltage switching (ZVS) ultra-large gain converter. By implementing coupled-inductor (CI) and built-in transformer (BIT) together with a switched capacitor (SC) voltage multiplier cell (VMC), a higher degree of flexibility is achieved for improvement of step-up voltage gain in comparison with those in which only one of these magnetic devices is utilised. Furthermore, the imposed voltage across the semiconductors is reduced by adjusting the turns ratio of the implemented CI and BIT. To further improve the efficiency, semiconductor devices with low ON-state resistance can be used. Moreover, to ensure ZVS turn-on, active clamp circuits are located in parallel with the main MOSFETs, which realize ZVS for all MOSFETs during an entire switching cycle. Minimizing the input current ripple as well as attenuating the reverse recovery problem of the diodes are the other advantages of this converter. Therefore, the proposed converter is a suitable candidate for those applications requiring high step-up gain and high conversion efficiency, such as renewable energy systems. To validate the performance of the proposed converter, a 600 W prototype with 22-380 V voltage conversion is designed, fabricated, and tested. Experimental results confirm that the proposed converter outperforms the previously presented ones in terms of the voltage gain and efficiency.

The design, which is based on the concept of reliability, is impressive. In power electronic circuits, the reliability design has been shown to be useful over time. Moreover, power loss in switches and diodes plays a permanent role in reliability assessment. This paper presents a reliability evaluation for a buck converter based on thermal analysis of an insulated-gate bipolar transistor (IGBT) and a diode. The provided thermal analysis is used to determine the switch and diode junction temperature. In this study, the effects of switching frequency and duty cycle are considered as criteria for reliability. A limit of 150°C has been set for over-temperature issues. The simulation of a 12 kW buck converter (duty cycle = 42% and switching frequency = 10 kHz) illustrates that the switch and diode junction temperature are 117.29°C and 122.27°C, respectively. The results show that mean time to failure for the buck converter is 32,973 hours.

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