A Virtual PV Systems Lab for Engineering Undergraduate Curriculum

Design and utilization of a Virtual Photovoltaic Systems Laboratory for undergraduate curriculum are introduced in this paper. The laboratory introduced in this study is developed to teach students the basics and design steps of photovoltaic solar energy systems in a virtual environment before entering the field. The users of the proposed virtual lab will be able to determine the sizing by selecting related parameters of the photovoltaic system to meet DC and AC loading conditions. Besides, the user will be able to analyze the effect of changing solar irradiation and temperature levels on the operating characteristics of the photovoltaic systems. Common DC bus concept and AC loading conditions are also included in the system by utilizing a permanent magnet DC motor and an RLC load as DC and AC loading examples, respectively. The proposed Virtual Photovoltaic Systems Laboratory is developed in Matlab/Simulink GUI environment. The proposed virtual lab has been used in Power Systems Lab in the Department of Electrical and Electronics Engineering at Karadeniz Technical University as a part of undergraduate curriculum. A survey on the students who took the lab has been carried out and responses are included in this paper

Dağıtım Sistemleri için Kendinden Ayarlanabilir FACTS Cihazı ve Denetleyicisi

In this paper, a FACTS based dynamic switched C-type filter (DSCTF) compensator scheme for distribution systems is presented with different load characteristics and control strategies. In order to suppress power quality problems and increase overall energy utilization efficiency; design and digital realization of the DSCTF consisting of dynamic control strategies are studied. Matlab/Simulink Software Environment is employed to validate the effectiveness of FACTS DSCTF device. It has been shown that the proposed FACTS-DSCTF is effective to mitigate power quality and energy utilization problems as well as in compensating voltage disturbances and current harmonics.Bu çalışmada, dağıtım sistemleri için FACTS tabanlı dinamik anahtarlamalı C-tipi filtre (DSCTF) kompanzatörü, farklı denetim stratejileri ve yük karakteristikleri ile sunulmaktadır. Enerji kullanım verimini artırmak ve güç kalitesi problemlerini bastırmak için dinamik denetim stratejilerini içeren DSCTF nin tasarımı ve dijital gerçekleştirilmesi çalışılmıştır. FACTS DSCTF cihazının etkinliğini doğrulamak için Matlab/Simulink yazılım ortamı kullanılmıştır. Önerilen FACTS-DSCTF in güç kalitesi ve enerji kullanım problemlerini azaltmanın yanı sıra gerilim bozukluklarını ve akım harmoniklerini de kompanzasyonunda etkili olduğunu göstermektedir

Analysis of Surface Roughness and Flank Wear Using the Taguchi Method in Milling of NiTi Shape Memory Alloy with Uncoated Tools

The aim of this study was to optimize machining parameters to obtain the smallest average surface roughness (Ra) and flank wear (Vb) values as a result of the surface milling of a nickel-titanium (NiTi) shape memory alloy (SMA) with uncoated cutting tools with different nose radius (rε) under dry cutting conditions. Tungsten carbide cutting tools with different rε (0.4 mm and 0.8 mm) were used in milling operations. The milling process was performed as lateral/surface cutting at three different cutting speeds (Vc) (20, 35 and 50 m/min), feed rates (fz) (0.03, 0.07 and 0.14 mm/tooth) and a constant axial cutting depth (0.7 mm). The effects of machining parameters in milling experiments were investigated based on the Taguchi L18 (21 × 32) orthogonal sequence, and the data obtained were analyzed using the Minitab 17 software. To determine the effects of processing parameters on Ra and Vb, analysis of variance (ANOVA) was used. The analysis results reveal that the dominant factor affecting the Ra is the cutting tool rε, while the main factor affecting Vb is the fz. Since the predicted values and measured values are very close to each other, it can be said that optimization is correct according to the validation test results