Communications Internationales
Permanent URI for this collectionhttps://dspace.univ-boumerdes.dz/handle/123456789/11
Browse
6 results
Search Results
Item Lifetime estimation and reliability of PV inverter with Multi-Timescale thermal stress analysis(IEEE, 2019) Bouguerra, Sara; Agroui, Kamel; Gassab, Oussama; Sangwongwanich, Ariya; Blaabjerg, FredeThe reliability of the PV inverter is a critical issue because it is the less reliable component of the PV system. In order to lower the risks of failure and maintenance in PV systems, the factors that influence the PV inverter lifetime should be analyzed. Thermal stress is the main causes of IGBT failure in a PV inverter, which includes the fast cycling stress due to loss variations in an IGBT, and slow cycling due to mission profile fluctuations. In this paper, the design for reliability (DFR) approach based on mission profile analysis is used and demonstrated on a single phase, single stage, grid connected PV inverter installed in Algeria, where the lifetime is estimated by taking the effect of low frequency thermal cycling under long-term operation into consideration, in addition to the line frequency power cycling due to loss variations. The results reveal that low frequency thermal cycling have a significant impact on lifetime degradation and reliability of the PV inverter after many years of operationItem Power transformer differential relay reliability assessment using false trip root cause analysis(IEEE, 2020) Zitouni, AbdelkaderPower transformer is vital element in power grid. Its failure may affect on the continuity of supply of electrical energy to the consumers. A differential relay, which is generally used for protecting this power transformer, may be affected by the disturbances such as inrush current, current transformer saturation and over-excitation due to external faults. Accordingly, false trips (mal-operation) of protection system may be resulted in. This research work proposes root cause analysis based on fault tree analysis to be used for assessing disturbances that lead to false trips. When the critical root causes are identified, mitigation measures are used. The model of security can help to quantify analytically the reliability of the considered protection systemItem Reliability Analysis and Energy Yield of String-Inverter Considering Monofacial and Bifacial Photovoltaic Panels(IEEE, 2020) Bouguerra, Sara; Yaiche, M.R.; Sangwongwanich, A.; Blaabjerg, F.; Liivik, E.Bifacial PV panels are emerging technologies that can increase the energy yield of the footprint in PV systems and thereby potentially reduce the cost of energy compared to the conventional monofacial PV panels. However, the increased energy yield due to the capability of harvesting the solar energy from both front and rare surfaces of the panel can potentially increase the loading of the inverters used in the system for doing grid connection, and as a consequence affect the inverter reliability performance. This paper thus provides a comparison between monofacial and bifacial PV modules in terms of reliability of the PV inverter and energy yield of the overall system. The analysis is carried out with a mission profile from Algiers, Algeria, where different Albedo and PV module installation heights are considered. The results show that both aspects can affect the lifetime of the PV inverter considerably, and they should be taken into consideration during the design of PV inverter.Item PC based testing system for protective relay(IEEE, 2013) Chafai, Mahfoud; Bentarzi, Hamid; Ouadi, Abderrahmane; Zitouni, Abdelkader; Recioui, AbdelmadjidItem Study for a mechanism aided by asynchronous actuator powered by asynchronous diesel generator(Caltek s.r.l., 2011) Meglouli, H.; Ikhlef, B.The modern electric facilities are equipped by a great number of different mechanisms and devices activator by Asynchronous electric Motor (ASM), the power of these motors is equal to the power of the generating devices, where their most complicated working regime is the starting when their power is equal to the power of the generating devices. In this regime we can have an overcharge of the generating devices by the active and reactive power. For this reason, this article is dedicated to the study of the starting methods of asynchronous motors that action the mechanisms and that are powered by Asynchronous Generating Diesel (AGD) with a limited capacity of DRY value and a given couple of resistanceItem Application of the binary decision diagram (BDD) in the analysis of the reliability of the inverters(IEEE, 2013) Mahdi, Ismahan; Nadji, B.