قابلیت اطمینان سیستم انتقال یک موضوع مهم در مسئله برنامه‌ریزی توسعه شبکه انتقال(TNEP) است. اکثر مقالات و تحقیقات در مورد TNEP از معیار امنیت N-1 برای فرمول‌بندی قابلیت اطمینان سیستم انتقال استفاده می‌کنند، در حالی که تعداد کمی از آنها شاخص بارزدایی (LS) برای برآورده کردن قابلیت اطمینان مورد نیاز مصرف‌کنندگان را در نظر گرفته‌اند. بنابراین، یک ارزیابی اقتصادی برای روشن شدن اینکه کدام یک از این معیارهای قابلیت اطمینان برای مطالعات برنامه‌ریزی توسعه انتقال مناسب‌تر است، ضروری است. در این مقاله سعی شده است این شاخص های قابلیت اطمینان با یکدیگر مقایسه شده و نشان داده شود که کدام یک از آنها برای برنامه‌ریزی توسعه یک سیستم انتقال اقتصادی‌تر هستند. هدف این است که بین هزینه‌های توسعه خطوط انتقال و پست‌ها، تلفات شبکه و قابلیت اطمینان سیستم با در نظر گرفتن هزینه‌های نگهداری و تعمیر و همچنین هزینه جایگزینی خطوط فرسوده، مصالحه ایجاد شود. برای فرمول‌بندی قابلیت اطمینان شبکه، ابتدا معیار امنیت قطعی N-1 به کار گرفته شده و نتایج مورد بحث قرار گرفته است، سپس معیار N-1 با شاخص قابلیت اطمینان احتمالی بارزدایی در فرمول TNEP جایگزین شد و نتایج با نتایج مدل اول مقایسه شده است. هر دو مدل TNEP روی شبکه 6 باس معروف Garver و سیستم تست 24 باس IEEE RTS تست شده اند. تفاصيل المقالة

این مقاله به بررسی و تحلیل تخلیه جزیی بر روی شینه‌های استاتور ژنراتور سنکرون می‌پردازد. لازم است در ابتدا، با استفاده از تجهیزات مربوطه، اندازه‌گیری سیگنالهای خاص این نوع تخلیه در دفعات و زمان‌های مختلف انجام گیرد و سپس با توجه به قواعد و استانداردهای موجود به تفسیر آنها پرداخته شود. به منظور تفسیر بهتر نتایج، یک شبکه عصبی مورد آموزش، آزمون و صحت سنجی قرار گرفته است. شبکه عصبی مورد استفاده، شبکه پرسپترون پیشرو دو لایه می‌باشد که با روش لونبرگ مارکوارت با در نظر گرفتن حداقل‌سازی مربعات خطا به عنوان شاخص عملکرد، مورد آموزش قرار گرفته است. به عنوان تست سیستم نمونه، آزمایش بر روی سه ژنراتور میتسوبیشی نیروگاه گازی شهر ری که هر کدام با توان نامی 85 مگاوات به تولید می‌پردازند، انجام گرفته است. در استاتور ژنراتور سنکرون عموماً وجود تخلیه الکتریکی در محل تماس شینه‌ها با بدنه استاتور، ورقه ورقه شدن داخلی شینه‌ها، وجود لقی در داخل دیواره عایق اصلی و ایجاد تخلیه در داخل شیار نتایج حاصل از تحلیل تخلیه جزیی می‌باشند تفاصيل المقالة

This paper proposes a robust method for frequency control in an islanded microgrid facing solar unit uncertainties. Here, microgrids with photovoltaic panels, battery energy storage systems, diesel generators, and fuel cells are considered. This paper focuses on the frequency constancy of stand-alone microgrids for reaction to these uncertainties. There are so many ways to control the frequency of microgrids, such as the PI control method, but these methods can't be useful in the case of uncertain systems. Due to the small scale of energy generation, the microgrid inertia changes with these uncertainties. Robust control is a method for frequency control that can be used in a situation of uncertainties, perturbations and frequency instability. In this article H_∞ frequency control is used for a microgrid with a dual peak load profile in the case of different coefficient penetrations of the solar panel. The results demonstrated that the battery energy storage system's coefficient penetration and the solar cell significantly affect microgrid frequency. A smart algorithm is proposed to determine the best coefficient penetration value for battery energy storage system available electricity and solar panels. تفاصيل المقالة

The application of sufficiently intense electric fields to insulators induces finite currents and then the insulators become conductive. This phenomenon is called dielectric breakdown and known as a fundamental non-equilibrium and nonlinear transport phenomenon in solids. Partial discharge (PD) is a small electrical avalanche caused by locally disrupted electric fields in dielectric materialsand is known to be one of the major factors which accelerates the degradation of electrical insulation. Pollution is the most important cause of external electrical failure of the insulator, fol-lowed by the operation of relays and the exit of transmission lines from the power grid. It is believed that the flashover and partial discharge phenomena are strongly related to environmental conditions such as temperature, humidity, pressure, pollution, and even space charges. In this review paper, we will identify the types of insulators associated with pollution sources and present laboratory results while defining partial discharge and its effects on equipment. تفاصيل المقالة

In this article, the most important factors affecting the discharge characteristics of high voltage insulators will be investigated. The type and severity of pollution, geographical and climatic conditions such as fog, rain, and wind, as well as the height above sea level, and finally the appearance and constituent materials of insulators will be studied as the main influencing factors in causing flashes on their surface. In addition to its severity, the type of pollution has a great effect on the electrical properties of insulators. This issue is discussed in the first section of the article for common types of pollution with different severities. Furthermore , a mixture of pollutants in the air is also examined, and the insulation waste is also shown in the case of design only based on sea salt, which is the worst type of pollution.In the next part, a review on the influence of climatic and geographical conditions has been performed, and in it, the effect of frost, wind, humidity and altitude on the start of electric discharge is discussed as the most important of them.And finally, the effect of appearance and its associated parameters as well as the constituent materials of insulators in pollution conditions are the last factors that will be considered. In addition, in this study, it has been shown how by intelligently changing these two factors, leakage current and discharge intensity can be reduced in contaminated insulators and their premature aging and failure can be delayed. تفاصيل المقالة

Technology development and increase in residential energy consumption cause moving toward automation and smart home (SH) to be inevitable. Recently, PVs and WTs resources attachment and CHP and Battery energy storage to SH equipment come to some challenges such as output power uncertainty to the energy management system (EMS). Usually, SH has a connection to the city distribution system and can buy or sell energy from or to the utility at the appropriate time. Therefore, this paper presents the new robustness of SH EMS considering real-time energy pricing at the retail power market, which is solved using genetic algorithm technique. The objective function is the summation of CHP emission cost and energy consumption cost for non-interruptible, interruptible and thermostatic loads. Finally, simulation results and numerical studies are applied on test SH, and conceptual results are discussed. تفاصيل المقالة

In this paper, the parameters of electric field and leakage current (LC) amplitude in polymeric insulator are calculated using finite element method (FEM) and predicted in the neural network. The variable angle and electrical conductivity of water droplets are changed. Increased electric field due to the presence of water droplets on the insulator surface causes the insulator breakdown probability. In this paper, for predicting the on the polymeric insulator leakage currents a neural network model was proposed, which could arrange for references to prevent contamination flashover. Through the study of a LC data obtained via the FEM simulation, the characteristics of the LC combined with BP neural network. Simulation results illustrate that enhancement in leakage current and electric field values are created when the values of the electrical conductivity and drop contact angle is increased. تفاصيل المقالة