Decentralized Demand Side Management with Rooftop PV in Residential Distribution Network

In the past extensive researches have been conducted on demand side management (DSM) program which aims at reducing peak loads and saving electricity cost. In this paper, we propose a framework to study decentralized household demand side management in a residential distribution network which consists of multiple smart homes with schedulable electrical appliances and some rooftop photovoltaic generation units. Each smart home makes individual appliance scheduling to optimize the electric energy cost according to the day-ahead forecast of electricity prices and its willingness for convenience sacrifice. Using the developed simulation model, we examine the performance of decentralized household DSM and study their impacts on the distribution network operation and renewable integration, in terms of utilization efficiency of rooftop PV generation, overall voltage deviation, real power loss, and possible reverse power flows.Comment: 5 pages, 7 figures, ISGT 2018 conferenc

Improving Grid Hosting Capacity and Inertia Response with High Penetration of Renewable Generation

To achieve a more sustainable supply of electricity, utilizing renewable energy resources is a promising solution. However, the inclusion of intermittent renewable energy resources in electric power systems, if not appropriately managed and controlled, will raise a new set of technical challenges in both voltage and frequency control and jeopardizes the reliability and stability of the power system, as one of the most critical infrastructures in the today’s world. This dissertation aims to answer how to achieve high penetration of renewable generations in the entire power system without jeopardizing its security and reliability. First, we tackle the data insufficiency in testing new methods and concepts in renewable generation integration and develop a toolkit to generate any number of synthetic power grids feathering the same properties of real power grids. Next, we focus on small-scale PV systems as the most growing renewable generation in distribution networks and develop a detailed impact assessment framework to examine its impacts on the system and provide installation scheme recommendations to improve the hosting capacity of PV systems in the distribution networks. Following, we examine smart homes with rooftop PV systems and propose a new demand side management algorithm to make the best use of distributed renewable energy. Finally, the findings in the aforementioned three parts have been incorporated to solve the challenge of inertia response and hosting capacity of renewables in transmission network

Optimized Solar Photovoltaic Generation in a Real Local Distribution Network

Remarkable penetration of renewable energy in electric networks, despite its valuable opportunities, such as power loss reduction and loadability improvements, has raised concerns for system operators. Such huge penetration can lead to a violation of the grid requirements, such as voltage and current limits and reverse power flow. Optimal placement and sizing of Distributed Generation (DG) are one of the best ways to strengthen the efficiency of the power systems. This paper builds a simulation model for the local distribution network based on obtained load profiles, GIS information, solar insolation, feeder and voltage settings, and define the optimization problem of solar PVDG installation to determine the optimal siting and sizing for different penetration levels with different objective functions. The objective functions include voltage profile improvement and energy loss minimization and the considered constraints include the physical distribution network constraints (AC power flow), the PV capacity constraint, and the voltage and reverse power flow constraints.Comment: To be published (Accepted) in: Proceedings of the IEEE PES Innovative Smart Grid Technologies Conference (ISGT), Washington D.C., USA, 201

Optimized Household Demand Management with Local Solar PV Generation

Demand Side Management (DSM) strategies are of-ten associated with the objectives of smoothing the load curve and reducing peak load. Although the future of demand side manage-ment is technically dependent on remote and automatic control of residential loads, the end-users play a significant role by shifting the use of appliances to the off-peak hours when they are exposed to Day-ahead market price. This paper proposes an optimum so-lution to the problem of scheduling of household demand side management in the presence of PV generation under a set of tech-nical constraints such as dynamic electricity pricing and voltage deviation. The proposed solution is implemented based on the Clonal Selection Algorithm (CSA). This solution is evaluated through a set of scenarios and simulation results show that the proposed approach results in the reduction of electricity bills and the import of energy from the grid

Comparison of canal displacement rate of mesiobuccal root of the maxillary first molar after the preparation by two manual and rotating methods using stainless steel hand files

زمینه و هدف: ابزارهای گوناگونی برای کاهش زمان آماده سازی کانال معرفی شده است. یکی از این ابزار هندپیس نوین (TEP-E10R) است که به نام اندوگریپر معروف است. این مطالعه با هدف مقایسه میزان تغییر مرکزیت کانال ریشه مزیوباکال مولر اول فک بالا به دنبال آماده سازی به دو روش دستی و چرخشی با استفاده از فایل های دستی استنلس استیل انجام شده است. روش بررسی: در این مطالعه تجربی آزمایشگاهی 50 دندان کشیده شده مولر اول ماگزیلای انسانی انتخاب و به دو گروه تقسیم شدند. بعد از تهیه حفره دسترسی و قرار دادن فایل اولیه داخل کانال مزیو باکال، رادیو گرافی های دیجیتالی به صورتی که رابطه فیلم و زاویه تابش با نمونه ها ثابت باشند تهیه گردید، سپس آماده سازی کانال ها در گروه اول با فایل های استنس استیل به روش دستی و در گروه دو با فایل های استنس استیل با اندوگریپر انجام شد. تکنیک آماده سازی کانال هادر هر دو گروه passive step back بود. پس از آماده سازی، رادیوگرافی با فایل مستر اپیکال با همان شرایط رادیوگرافی اول انجام گرفت. میزان تغییر مرکزیت کانال رادیو گرافی اولیه و رادیوگرافی با فایل اصلی بر اساس تصاویر انطباقی بر حسب میلی متر توسط نرم افزار فتوشاپ و به کمک رادیولوژیست محاسبه شد. یافته ها: میانگین انحراف از مسیر اصلی کانال در گروه اول (36/1±45/3 میلیمتر) بیشتر از گروه دوم (69/1±75/1 میلیمتر) بود (045/0=P). همچنین میانگین زمان آماده سازی کانال ها در گروه اول (53/1±36/19 دقیقه) بیشتر از گروه دوم (55/1±03/12 دقیقه) بود (0001/0=P). نتیجه گیری: استفاده از فایل های استنلس استیل با هندپیس (رفت و برگشتی) reciprocal نسبت به استفاده از فایل های استنلس استیل به تنهایی مسیر اصلی کانال را بهتر حفظ می کند