research centers


Search results: Found 10

Listing 1 - 10 of 10
Sort by

Article
Reducing the Impacts of Distributed Generation in Transmission & Distribution Networks Protection Using Fault Current Limiters
الحد من تأثیر المولدات الموزعة (DG) في حمایة شبكات النقل والتوزیع بإستخدام محددات لتیار العطل

Author: Wafaa Saeed
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2013 Volume: 31 Issue: 12 Part (A) Engineering Pages: 2273-2291
Publisher: University of Technology الجامعة التكنولوجية

Loading...
Loading...
Abstract

Increase in power generation capacity of electric power systems has lead toincrease in the fault current level. In some cases fault current levels are exceeding theinterrupting capability of existing transmission and distribution substations circuitbreakers. Since short-circuit currents contain extremely high energy and can damageelectrical equipment, either requires the replacement of a large number of existingsubstation breakers with higher rating breakers or the development of some means tolimit fault current. Different technologies have been employed to design Fault CurrentLimiters FCLs such as turn-off a solid state switch to using superconductors thatrespond with increasing resistance in event of fault current. A proper design ofModular Level Based Solid-State Fault Current Limiters is proposed in this paper,describes the functioning of FCL and the amount of impedance they are required toinsert in series with transmission or distribution substation are discuses. This willallow near instantaneous breaking of bus ties in transmission and distributionsubstations to reduce the available short circuit current and allow existing circuitbreakers to clear at lower fault current levels. Since FCL's are installed in each phaseof the line, the fault is viewed in perspective of per phase. For the purposes of thisstudy, we consider phase to ground fault& phase to phase fault scenarios.


Article
Distributed Generation Embedded In the Iraqi Power Grid
التولید الموزع المدموج في شبكة القدرة العراقیة

Authors: Qais Matti Alias --- Wael A. Jaafar
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2010 Volume: 28 Issue: 20 Pages: 6035-6049
Publisher: University of Technology الجامعة التكنولوجية

Loading...
Loading...
Abstract

Recently, there has been great interest in the integration of distributedgeneration units at the distribution level. This requires new analysis tools forunderstanding system performance. Installing Distribution Generation (DG) inthe distribution level has positive impacts on the system voltage profile as well onthe substation’ s capacity. However the extent of such benefits depends greatly ofthe DG size and location.In this work, investigation of adding diesel units regarded as distributedgenerators at the distribution voltage levels were done. These investigations dealtwith the impact of the units addition on the Iraqi grid power flow and short circuitlevels . This work is done by using PSS/E program (Power System Simulation forEngineering), A sample from substations (with fuel and space availability ) of theBaghdad area were considered for the diesel units addition, in order to findrecommendations for the voltage level to connect these units to it.The extension in mind was to develop a quick rule of thumb in order to decidewhere to add the DG units. This of course with no regard to the unit size as it islimited by the Short Circuit Level (SCL) and economic considerations. IEEEstandardsystems were considered here with the development of Matlab routinesfor the simulation and calculations required.A novel quick criterion as where to add the distributed generation to minimizeloss was proved. This state’s “add the units at the lowest short circuit level bus,i.e., at the bus of highest Thevenin impedance”.

حدیثا, كان ھناك اھتمام كبیر في ادخال وحدات التولید الموزع في مستویات التوزیع, وھذا یتطلب أدوات تحلیل جدیدة لفھم سلوك النظام. التولید الموزع المنصوب في مستویات التوزیع لھ تأثیرات ایجابیة على فولتیة النظام وكذلك على سعة المحطة الثانویة. وجود ھذه الفوائد یعتمد بشكل كبیر على حجم وموقعھذه الوحدات. في ھذا العمل تم التحقیق في إضافة وحدات دیزل ینظر لھا على أنھا وحدات تولید موزعة في مستویات التوزیع. ھذه التحقیقات تعاملت مع تأثیر إضافة الوحدات على سریان الحمل ومستوى الدورة القصیرة في الشبكة العراقیة. درست عینة من محطات بغداد الثانویة لإضافة وحدات الدیزل فیھا وذلك للخروج بتوصیات لنصب تلك الوحدات على أي مستوى من مستویات فولتیة التوزیع. وأیضا تم التوسع في التحقیقات لاستخراج قاعدة سریعة بسیطة لتقریر مكان إضافة وحدات التولید الموزع , ھذا مع عدم الأخذ بنض ر الاعتبار حجم الإضافات لكونھا محددة بمستوى الدورة القصیرة واعتبارات اقتصادیة أخرى.للدراسة مع تطویر MATLAB استخدمت منظومات تم اثبات . لعمل المحاكاة والحسابات المطلوبة IEEE روتینیات القیاسیة مقیاس جدید وسریع لمعرفة مكان إضافة التولید الموزع لتقلیل الخسائر, وھو ینص" أضف الوحدات على العمومي الأقل دورة قصیرة " .


Article
Optimal Size and Location of Distributed Generators using Intelligent Techniques
ألموقع والحجم ألامثلین للمولدات الموزعة بأستخدام التقنیات الذكیة

Authors: Rashid H. Al-Rubayi --- AzharM. Alrawi
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2010 Volume: 28 Issue: 23 Pages: 6623-6633
Publisher: University of Technology الجامعة التكنولوجية

Loading...
Loading...
Abstract

One of the modern and important techniques in electrical distributionsystems is to solve the networks problem of service availability, high loss and low voltage stability by accommodating small scaled de-centralized generating units in these networks, which is known as distributed generation (DG). The Genetic Algorithm (GA) technique is dedicated in this work to find the optimal DG locations, and then optimally allocate units in order to maximize the penetrationlevel, minimize loss, and improve voltage stability

یعتبر اضافة الوحدات التولیدیة الصغیره غیر المركزیھ في انظمة توزیع الطاقة الكھربائیة من أھم وأحدث الستراتیجیات الحدیثة لحل مشاكل تلك الانظمة من نقص التولید وزیادة الخسائر وضعف استقراریة الفولتیة , وتعرف تلك الستراتیجیة بالمولدات الموزعة.نتیجة للتطور والنمو في شبكات التوزیع فأن دراسة عملیة أضافة المولدات الموزعة ھي دراسة معقده من الناحیتین التقنیة والریاضیة , ونتیجة لذلك تم استخدام تقنیة الخوارزمیة الجینیة لتحدید أمثل المواقع للاضافة ثم اختیار افضل الاحجام لتلك المولدات لامداد الشبكة باقصى قدرة تولیدیة ممكنة وتقلیل الخسائر لاقل مایمكن و تحسین استقراریة الفولتیة


Article
Optimal Placement of Distribution Generating in Distribution System Based on Cost worth & System Reliability indices.
تحديد الموقع الامثل للمولدات الموزعة في نظم التوزيع على اساس دلائل كلفة قطع التجهيز ووثوقية النظام

Author: Dr. Wafaa Saeed د. وفاء سعيد مجيد
Journal: Univesity of Thi-Qar Journal مجلة جامعة ذي قار العلمية ISSN: 66291818 Year: 2016 Volume: 11 Issue: 2 Pages: 1-22
Publisher: Thi-Qar University جامعة ذي قار

Loading...
Loading...
Abstract

Electrical power systems include three functional areas: generation, transmission and distribution systems. Evaluate the reliability of the whole system is very complex so the present research is limited on evaluate the reliability of radial distribution system. Since the demand loads have continuously growth and uncertainties it became one of the important things to be observed, so that we can forecast an accurate demand loads in the future .To ensure the continuity of providing demand loads and the possibility of covering the expected increase demand the technology of injected Distributed Generation in a radial distribution system through circuit breaker was adoption. DG works to generate energy to cover the increased in demand loads or to compensate the shortfall in generation during a Failure. To enhances the reliability of the test system optimal location and size of DG should be identifies. Basic reliability indices for load points and the overall system have been developed. A additional reliability (i.e. cost worth& System Reliability) indices are suggested. The cost worth indices serve as a guide to locate position where reliability needs to be supported. The suggested approach has been tested on Roy Billinton Test System 6 bus with four radial feeders. The Results that we got from this approach clearly shows the best location and sizing of DG and so support the reliability of the system.

نظم القدرة الكهربائية تشمل ثلاث مناطق وظيفية: نظم التوليد والنقل والتوزيع ,وحيث ان تقييم وثوقيه المنظومة بأكملها عملية معقدة جداً تحدد البحث الحالي بتقييم وثوقيه منظومة توزيع شعاعية. ان الاحمال المربوطة للشبكة تتنامى بشكل مستمر ولامركزي وعليه اصبح التوقع للزيادة المستقبلية في الطلب على الطاقة من الامور الواجب مراعاتها لضمان استمرارية التجهيز في حالات الخروج القسري لا حدى الوحدات التوليدية او حدوث زيادة مفاجئة بالطلب على الطاقة اعلى من الطاقة التصميمة. من التقنيات المعتمدة تقنية حقن مولد كهربائي مع قاطع دورة للشبكة عند احد المغذيات على ان يتم فصلة عن الشبكة حال رجوع الحمل الى قيمته الاعتيادية. اضافة مولد كهربائي الى منظومة التوزيع يعزز من وثوقيه التجهير بشرط ان يكون المولد المضاف بالمكان والحجم الامثل وذلك من خلال احتساب دلائل وثوقيه المنظومة والدلائل المتعلقة بكلفة قطع التجهيز. تم اختبار الطريقة المقترحة على منظومة توزيع شعاعية مخصصة للأغراض التعليمية بواقع (6) عموميات و(4) مغذيات شعاعية واشارت النتائج الى ان اختيار الموقع والحجم الامثل يعزز من وثوقية النظام .


Article
Optimal Reconfiguration and Distributed Generation placement in Baghdad Distribution Sector

Authors: Inaam I. Ali --- Omar. Y. Saeed
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2018 Volume: 36 Issue: 3 Part (A) Engineering Pages: 333-343
Publisher: University of Technology الجامعة التكنولوجية

Loading...
Loading...
Abstract

The power losses in distribution system are high, which form 70 – 80% of total transmission and distribution losses. High losses have severe impact on stability, reliability as well as economy. Therefore, minimization of these losses is very necessary. In this paper proposed various schemes to reduce the active power losses in distribution network, given as:- Optimum reconfiguration network,- Optimum Distributed Generation (DG) placement and- Optimum reconfiguration with optimum (DG) placement.Using Cymdist software to implement the optimal reconfiguration algorithm and proposed Genetic Algorithm (GA) to find the size and location, which programmed under MATLAB software package. Whereon the proposed methodology (GA) simplifies the problem by dividing it in two phases, namely Placement Planning Model (PPM) and Size Planning Model (SPM) thereby reducing the search space. It was the integration of the two methods were used after each method individually to obtain minimum real power losses with better bus voltage (better efficiency for network).To verify the proposed algorithms, IEEE 33-bus system and al – jihad neighborhood distribution system (Baghdad distribution sector) are tested. The simulation results are compared with proposed works in literature.


Article
An Imperialist Competitive Algorithm for Sitting and Sizing of Distributed Generation in Radial Distribution Network to Improve Reliability and Losses Reduction

Authors: Farzaneh Ostovar --- Mahdi Mozaffari Legha
Journal: Iraqi Journal for Electrical And Electronic Engineering المجلة العراقية للهندسة الكهربائية والالكترونية ISSN: 18145892 Year: 2013 Volume: 9 Issue: 2 Pages: 59-66
Publisher: Basrah University جامعة البصرة

Loading...
Loading...
Abstract

Distributed Generation (DG) can help in reducing the cost of electricity to the costumer, relieve network congestion and provide environmentally friendly energy close to load centers. Its capacity is also scalable and it provides voltage support at distribution level. Hence, DG placement and penetration level is an important problem for both the utility and DG owner. The Optimal Power Flow (OPF) has been widely used for both the operation and planning of a power system. The OPF is also suited for deregulated environment.Four different objective functions are considered in this study: (1) Improvement voltage profile (2) minimization of active power loss (3) maximum capacity of conductors (4) maximization of reliability level. The site and size of DG units are assumed as design variables. The results are discussed and compared with those of traditional distribution planning and also with Imperialist competitive algorithm (ICA).


Article
STABILITY ENHANCEMENT BASED ON DISTRIBUTED GENERATION UNITS IN AL-NAJAF AL-ASHRAF ELECTRICAL NETWORK
تحسين الاستقرارية باستخدام التوليد الموزع في شبكة النجف الاشرف الكهربائية

Authors: Rashid Hameed Al-Rubayi رشيد حميد الربيعي --- Zaid Tariq Hasan زيد طارق حسن
Journal: KUFA JOURNAL OF ENGINEERING مجلة الكوفة الهندسية ISSN: 25230018 Year: 2016 Volume: 7 Issue: 1 Pages: 15-26
Publisher: University of Kufa جامعة الكوفة

Loading...
Loading...
Abstract

The operation and structure of distribution system are changing with the integration of Distributed Generation (DG) units, where these units may have effect on power losses, stability, voltage profile, power quality and other quantities. Therefore the optimum location, size and number of DG units are necessary to avoid the negative impacts on electric power system. In this work, the Particle Swarm Optimization (PSO) technique is used to find the optimal number and locations of DG in order to minimize the active power losses. The thermal limit of transmission lines and transformers was studied to detect the lines or transformers which exceed the limit in order to process it. The voltage stability of distribution network has been investigated, using L index method.

ان عمل وتركيب نظام التوزيع يتغير مع اضافة وحدات التوليد الموزع (DG )، حيث انها تؤثر على خسائر القدرة ، الاستقرارية ، الفولطية ، جودة الطاقة وكميات اخرى، لذلك فان اختيار الموقع الامثل والحجم وعدد وحدات التوليد الموزع (DG ) ضروري لتجنب التأثيرات السلبية على نظام الطاقة الكهربائية. في هذا البحث استخدمت تقنية (PSO ) لإيجاد العدد والموقع الامثلان لوحدات التوليد الموزع (DG ) لتقليل خسائر القدرة الفعالة. بعد ذلك تم دراسة الحد الحراري لخطوط نقل الطاقة الكهربائية والمحولات لتحديد الخطوط والمحولات التي تجاوزت الحد ومعالجتها. كذلك تم دراسة استقرارية الفولطية لشبكة التوزيع باستخدام طريقة ( L INDEX).  


Article
Protection Coordination with Distributed Generation in Electrical System of Iraqi Distribution Grid

Authors: Rashid H. Al-Rubayi --- Ammar Abbas Majeed
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2016 Volume: 34 Issue: 6 Part (A) Engineering Pages: 1161-1181
Publisher: University of Technology الجامعة التكنولوجية

Loading...
Loading...
Abstract

The nature characteristic in conventional distribution networks is radial by single source supplying a downstream network. The interest about the environmental impacts and development in technologies have led to increase distributed generation (DG) interconnected in distribution networks. Protective device coordination will be affected by adding DGs to the existing network through participating to the change in direction of power flow and fault current values and direction which cause loss in settings and mis-coordination for protective devices, especially over current relays. The effect of DG on coordination depend upon number, location and size of DG, so in this work, the Particle Swarm Optimization (PSO) technicality utilization to locate optimal location and sizeof DG to obtain minimum active power losses.The Time Current Characteristic (TCC) curves represented which depended on the over current protection relays parameters to find settings and limited any loss in it, in order to reset these relays to obtained the proper operation without intersections in time of operation and satisfy optimal coordination between primary and pack up over current protection relays.In this work two soft wares are used, the first is Matlab R2014a for implementation of the PSO algorithm while the second software is CYMDist program for load flow analysis, short circuit current calculation and protection coordination device analysis. To verify the developed algorithm parts from Iraqi distribution network (Baghdad Al-Rusafa 33KV distribution networks). So, used two DG units with total capacity 50MW distributed in 33kV of South Al-Rusafa distribution network which represented about 9.4% from the total load of this network 533.5MW, the total active power losses reduced from 11.597MW to 6.658MW with losses reduction 6.96MW about 43% from total losses.


Article
Controlling Voltage Levels of Distribution Network-Radial Feeder after Connecting Wind Turbines to the Network

Author: Muhammad Al Badri
Journal: Journal of University of Babylon مجلة جامعة بابل ISSN: 19920652 23128135 Year: 2018 Volume: 26 Issue: 1 Pages: 331-337
Publisher: Babylon University جامعة بابل

Loading...
Loading...
Abstract

Several factors in power generation and supply need to be taken into account such as shortages of energy supply, system stability, and energy quality and system disruption due to network losses, industrial development and population expansion. The addition of wind turbines to the distribution network is of great benefit in providing additional power and solving these problems, but this addition is accompanied by the problem of low voltage network. This research found optimal solutions to the problem of low voltage distribution network after connecting wind turbines. The main idea of this paper is to optimize the low-voltage problem as a result of connecting the wind turbines to the "far end" of the radial feeder for a distribution network and to obtain a voltage level within an acceptable and stable range. The problem of low voltage solved by using the load-drop compensation, capacitor-bank and “doubly-fed” induction generators. The results of this study were based on the operation of the entire design of the simulation system which would be compatible with the reality of the energy flow of all network components by using the PSCAD program. The present analysis program revealed an optimum solution for the low voltage profile of the distribution network after connecting the wind turbine.

عدة عوامل يجب ان تأخذ بنظر الاعتبار عند توليد الطاقة الكهربائية مثل، نقص إمدادات الطاقة، استقرار النظام، نوعية الطاقة، وتعطل النظام بسبب خسائر الشبكة نتيجة التنمية الصناعية والتوسع السكاني. اضافة توربينات الرياح الى شبكة التوزيع تساهم في توفير طاقة إضافية وحل هذه المشاكل، ولكن هذه الإضافة ترافقها مشكلة الجهد المنخفض للشبكة. الفكرة الرئيسية لهذا البحث هو الحفاظ على مستوى فولتية لوحدة تغذية شعاعية لشبكة توزيع ضمن نطاق مقبول وثابت عند إدخال توربينات الرياح إلى وحدة التغذية في "الطرف البعيد". هذا البحث يبحث في ايجاد الحل الامثل لمشكلة الجهد المنخفض لشبكة التوزيع بعد ربط توربينات الرياح. نتائج هذه الدراسة اعتمدت البرنامج “PSCAD” لتشغيل تصميم كامل لنظام المحاكاة التي ستكون متوافقة مع واقع تدفق الطاقة لجميع مكونات الشبكة . كشف برنامج التحليل الحالي عن الحل الأمثل لملف الجهد المنخفض لشبكة التوزيع بعد توصيل توربينات الرياح.


Article
MODELING AND ANALYSIS OF A FOUR-LEG INVERTER USING SPACE VECTOR PULSE WIDTH MODULATION

Authors: Isam Mahmood Abdulbaqi --- Ali Husain Ahmed --- Riyadh Ghanim Omar --- Abdullah Sahib Abdulsada
Journal: Journal of Engineering and Sustainable Development مجلة الهندسة والتنمية المستدامة ISSN: 25200917 Year: 2019 Volume: 23 Issue: 2 Pages: 100-119
Publisher: Al-Mustansyriah University الجامعة المستنصرية

Loading...
Loading...
Abstract

The bad effect of zero sequence current in unbalanced load when connected to three-leg inverter, is the main challenge leading to add fourth leg and using three dimensional space vector pulse width modulation (3-D) SVPWM technique to handle this problem. The paper presents an analysis and study of this technique, depending on the average large signal model. This technique simulated by using Matlab/Simulink and the results shows good performance with low THD for different operating conditions.

Listing 1 - 10 of 10
Sort by
Narrow your search

Resource type

article (10)


Language

English (10)


Year
From To Submit

2019 (1)

2018 (2)

2016 (3)

2013 (2)

2010 (2)