امروزه حضور منابع تولید پراکنده این شبکه‌ها را به حالت پویا تبدیل کرده‌است. تغییر حرکت جریان، افزایش میزان جریان خطا و به دنبال آن از دست رفتن هماهنگی و همچنین اشتباه در عملکرد رله‌های نواحی سالم در شبکه از جمله مشکلات استفاده از این منابع بوده است. پیدا کردن راه حل برای رفع این دسته از مشکلات در طول سالیان متوالی، همواره چالش برانگیز بوده است. هدف این مقاله ارائه یک راه حل جدید در بررسی عملکرد سیستم حفاظت شبکه‌‌‌‌‌‌‌های انرژی الکتریکی به کمک تجهیزات هوشمند الکترونیکی و با استفاده از پروتکلهای ارتباطی موجود در سطح شبکه‌‌‌‌‌‌‌های توزیع می‌باشد. در سالهای اخیر استفاده از بستر مخابراتی و بکارگیری تجهیزات هوشمند بستری را فراهم کرده که توانسته است کارآمدی خود را در برابر تغییرات ناگهانی شبکه نشان دهد. سیستم چندعاملی، نام این بستر ارتباطی می‌باشد که توانسته است با طرحی نو، پیشگام در شروع یک تحول بنیادی در طراحی سیستمهای حفاظتی شبکه‌‌‌‌‌‌‌های انرژی الکتریکی باشد. این سیستم‌‌‌‌‌‌‌ها نشان داده‌اند که بدون مشکل نیز نبوده‌ و در مواردی شبکه را با مشکلاتی مواجه کرده‌اند. در طرح پیشنهادی ساختار چندلایه سیستم چندعاملی شکسته شده و سطوح از وابستگی یکدیگر خارج خواهند شد. بر خلاف روش حفاظتی سیستم چندعاملی که در گذشته وجود داشته است، تنظیمات حفاظتی در لحظه خطا برای تمام شبکه محاسبه نمی‌گردد. این مسئله که در روش‌‌‌‌‌‌‌های قبلی دیده نشده چگالی بار زیادی را هم از روی واحد مرکزی برداشته و سرعت عملکرد و قابلیت اطمینان در عملکرد سیستم حفاظت را بالا می‌برد. پرونده مقاله

اکثر ریزمنابع از طریق مبدل‌های الکترونیک قدرت به ریزشبکه متصل می‌شوند. بنابراین، ریزشبکه می‌تواند به عنوان یک گروه از مبدل-های موازی در نظر گرفته شود. یک روش شناخته شده برای کنترل گروهی از مبدل‌های موازی در ساختار کنترل غیر متمرکز در یک ریزشبکه‌ی جزیره‌ای، استفاده از مشخصه‌های افتی فرکانس و ولتاژ است. مشکل استفاده از مشخصه‌های افتی معمول این است که تقسیم توان راکتیو متناسب با ظرفیت ریزمنابع میان آن‌ها انجام نمی‌شود. این موضوع ممکن است منجر به اضافه بار شدن مبدل‌ها گردد. ماهیت مشخصه‌های افتی مرسوم خطی است. بنابراین این مشخصه‌ها درجه‌ی آزادی کافی برای عملکرد مناسب در شرایط غیرخطی همچون وقوع خطای اتصال کوتاه را ندارند. راه‌حل‌های ارایه شده برای این مشکل عمدتاً محدود به ریزشبکه‌های با ساختار خاص بوده و یا نیازمند دانستن اطلاعات وسیع از شبکه می‌باشد. به همین منظور در این مقاله یک استراتژی‌ جدید کنترل توان مبتنی بر روش غیرمتمرکز برای یک ریزشبکه خودگردان متشکل از منابع ولتاژ اینورتری ارایه شده است. استراتژی کنترل پیشنهادی بر پایه‌-ی روش‌های افتی معمول بنا نهاده شده است. در روش پیشنهادی مشخصه‌های افتی معمول از طریق تنظیم عرض از مبدأ و با استفاده از حلقه‌ی امپدانس مجازی به گونه‌ای اصلاح می‌گردنند که نسبت به تغییرات نقطه‌ی کار منابع موجود در ریزشبکه به صورت وفقی و به سرعت پاسخ داده و منجر به تقسیم توان اکتیو و راکتیو ایده‌آل گردند. همچنین رویکرد پیشنهادی منجر به بهبود تنظیم ولتاژ هم در شرایط عادی ریزشبکه و هم در هنگام وقوع خطا می‌شود. پرونده مقاله

The power system stabilizer (PSS) is capable of improving network stability by damping oscillations. PSSs generate control signals for exciting system which are used to damp volatility resulting from impairment of the power system. To overcome the shortcomings of the conventional power system stabi lizers by the use of feedback linearization control (FBLC) and H-infinity (H¥) robust optimal control, two synchro no us generator excit i ng system controllers were designed. The main objective is to design these controls to adjust the voltage and improve the stability of the power system small signal simultaneously despite uncertainty and disruptions to enter the power system. The simulation results obtained by MATLAB in a single machine to infinite bus (SMIB) system show that control proper functioning in different operational conditions, and are designed to be an appropriate alternative to conventional with automatic voltage regulator (AVR). پرونده مقاله

Many researchers have proposed small signal analysis methods and numerous power system stabilizers designed by system linearization. In these approaches, it is assumed that disturbances are so small and the linear approximation error of a nonlinear power system remains in an acceptable range. However, the approximation can restrict the validity of linearized models to a neighborhood of equilibrium points. In this paper, in order to reduce the concerns related to the linearization of the power system and damping of electromechanical oscillations, the synergistic nonlinear control method has been used. In addition, a decentralized control strategy was proposed for the use of power system stabilizers in multi-machine power systems. The relation between generators was modelled as a function of variables and its effects on a single machine connected to an infinite bus power system were examined under various disturbances. Also, three test systems were used to verify the efficiency of the proposed decentralized synergetic method. The simulation results showed that the proposed power system stabilizer was more effective than other stabilizers such as a multi-band power system stabilizer in local and inter-area mode oscillations and under different disturbances. پرونده مقاله

The microgrid consists of several distributed generation units and operates in two modes, connected to the network and autonomous. A good microstructure, especially in autonomous mode, requires a power management strategy. In an island microgrid, there are two methods of centralized and decentralized control. In an island microgrid, the slope changes characteristic of the frequency droop of the source frequency have the greatest effect on the dynamics of the system's response to disturbances in the microgrid. In this paper, the inverter-based microgrid droop control method in island operation mode is analyzed and simulated. The studied system has three scattered sources and six local times. The simulation results are shown using MATLAB software for different modes. پرونده مقاله

Renewable energy sources offer geographical opportunities for enhanced energy efficien-cy. However, the substantial integration of renewable energy production into distribution systems introduces uncertainties and technical complexities by impacting the network per-formance and protection mechanisms. Distributed generation (DG) enhances power grid efficiency, yet its influence on protection systems raises concerns about fault detection and isolation within active distribution networks. This study introduces a method to coordinate protection devices by inverter current control of distributed production sources during faults. The paper compares the impact of dispersed resources on flow dynamics during fault conditions. ETAP software simulations validate the proposed approach, addressing challenges in coordinating and regulating protection devices when integrating diverse re-sources into the network. This method restores coordination and enhances the reliability of protection systems. In summary, this research emphasizes the challenges of integrating re-newable energy into distribution systems, highlighting the need for effective protection co-ordination. The proposed method contributes to mitigating these challenges, ensuring de-pendable and efficient active distribution networks پرونده مقاله

Load changes affect the frequency of electrical networks. Frequency stabilization is very important due to the increasing penetration of renewable energy sources in power systems. Load frequency control (LFC) is used in the power system, so that the frequency of the programmed system and the power of the connection line of an interconnected area are within the specified limits. To improve the dynamic performance of the power system and control the frequency stability, LFC is used in power systems. The main task of LFC is to keep the system frequency according to the specified nominal value and to maintain the correct amount of exchange power between the control areas. In this paper, load frequency control in two-area power system is studied and simulated. Each area has a steam generating unit with a reheat steam turbine. The system equations are expressed in the state space and the system model is determined based on the transfer function. The simulation results have been obtained using Matlab software. The simulation results show the effect of Richter's parameters on the transient dynamic behavior of the system. پرونده مقاله

Load changes affect the frequency of electrical networks. Frequency stabilization is very important due to the increasing penetration of renewable energy sources in power systems. The main task of load frequency control is to keep the system frequency according to the specified nominal value and to maintain the correct amount of exchange power between the control areas. Load frequency control in two-area power system is studied and simulated in this paper. Each area has a steam generating unit with a reheat steam turbine. The system equations are expressed in the state space and the system model is determined based on the transfer function. The simulation results have been obtained using Matlab software. The simulation results show the effect of reheater on the transient dynamic behavior of the two-area power system. پرونده مقاله

Renewable energy sources are used as distributed generation (DG) sources in distribution networks. Inverter microgrids (MGs) in island operation are nonlinear systems with multiple dynamic modes. One of the main advantages of a microgrid is its ability to operate in islanded mode, where the DGs are responsible for providing both active and reactive power requirements by themselves. The distinguishing feature of distributed generation, with power electronic interfaces, which usually work as voltage source inverters, is the flexibility to provide controlled and high-quality energy. In this paper, the dynamic model of a microgrid based on inverter voltage sources in the first level of control is used. The behavior of a microgrid in the time domain is simulated and the performance of a microgrid is shown in three different modes. The inverter source control model including power control loops, voltage control and current control loops as well as the LC filter of the source output in the dq biaxial reference device are used. The simulation results show that with conventional dropout strategies, the active power distribution is done properly between sources, but it is not accurate enough to distribute the reactive power between the resources of a microgrid. پرونده مقاله