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Full-Text Articles in Physical Sciences and Mathematics

Optimization Of Grid Connected Micro-Grid Consisting Of Pv/Fc/Uc With Considered Frequency Control, Hamid Hasanzadehfard, Masoud Moghaddas-Tafreshi, Sayed Mehdi Hakimi Jan 2015

Optimization Of Grid Connected Micro-Grid Consisting Of Pv/Fc/Uc With Considered Frequency Control, Hamid Hasanzadehfard, Masoud Moghaddas-Tafreshi, Sayed Mehdi Hakimi

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, ultracapacitors are used as short-term storages for the frequency control of grid-connected microgrid that consists of photovoltaic panels, fuel cells, and the battery packs as long-term storages. Fuel cells and battery packs have delays in load tracking; therefore, ultracapacitors are used to compensate for the sudden power fluctuations in the microgrid that occur due to the output power uncertainty of the PV arrays and the loads required in the microgrid, as well as the sudden interruption of the main grid. The microgrid consists of interruptible and uninterruptible loads. When the total produced power in the microgrid, in …


Reliability Assessment Of A Standalone Wind-Conventional/Energy Storage System Using Probabilistic Production Simulation Method, Hossein Delavaripour, Behzad Mirzaeian Dehkordi Jan 2015

Reliability Assessment Of A Standalone Wind-Conventional/Energy Storage System Using Probabilistic Production Simulation Method, Hossein Delavaripour, Behzad Mirzaeian Dehkordi

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a reliability evaluation technique for a small standalone system including wind and conventional resources integrated with an energy storage system. A battery bank is considered as the energy storage system. The focus in this analysis is on the effect of battery modeling and its performance on system reliability. In this way, this paper presents an accurate model for the electrochemical batteries, which takes into account all the influential characteristics of the battery related to reliability studies, such as depth of charge, efficiency of charge, and rate of discharge. The proposed reliability evaluation method is based on the …


Improving The Drain-Current Expression Of Bsim4 For Hot-Carrier Degradation Modeling That Is Suitable For Analog Applications, Gürsel Düzenli̇ Jan 2015

Improving The Drain-Current Expression Of Bsim4 For Hot-Carrier Degradation Modeling That Is Suitable For Analog Applications, Gürsel Düzenli̇

Turkish Journal of Electrical Engineering and Computer Sciences

The reliability evaluation of MOS transistors is one of the most important subjects in device engineering and VLSI design. The down-scaling of device dimensions adversely affects device reliability and lifetime. Although different factors contribute to device reliability and lifetime, the most influential factor is hot-carrier degradation. Furthermore, hot-carrier degradation affects each application uniquely. In analog applications, hot-carrier degradation is more complex and diverse relative to digital applications. In this study, we improve the BSIM4 drain-current model to develop a hot-carrier degradation model that is suitable for both analog and digital applications. Our approach is readily applicable to all process technologies …


Simulation Study Of Hemt Structures With Hfo2 Cap Layer For Mitigating Inverse Piezoelectric Effect Related Device Failures, Deepthi Nagulapally, Ravi P. Joshi, Aswini Pradhan Jan 2015

Simulation Study Of Hemt Structures With Hfo2 Cap Layer For Mitigating Inverse Piezoelectric Effect Related Device Failures, Deepthi Nagulapally, Ravi P. Joshi, Aswini Pradhan

Electrical & Computer Engineering Faculty Publications

The Inverse Piezoelectric Effect (IPE) is thought to contribute to possible device failure of GaN High Electron Mobility Transistors (HEMTs). Here we focus on a simulation study to probe the possible mitigation of the IPE by reducing the internal electric fields and related elastic energy through the use of high-k materials. Inclusion of a HfO2 "cap layer" above the AlGaN barrier particularly with a partial mesa structure is shown to have potential advantages. Simulations reveal even greater reductions in the internal electric fields by using "field plates" in concert with high-k oxides