Distribution network optimisation for an active network management system

The connection of Distributed Generators (DGs) to a distribution network causes technical concerns for Distribution Network Operators (DNOs) which include power flow management, loss increase and voltage management problems. An Active Network Management System can provide monitoring and control of the distribution network as well as providing the infrastructure and technology for full integration of DGs into the distribution network. The Optimal Power Flow (OPF) method is a valuable tool in providing optimal control solutions for active network management system applications. The research presented here has concentrated on the development of a multi-objective OPF to provide power flow management, voltage control solutions and network optimisation strategies. The OPF has been shown to provide accurate solutions for variety of network topologies. It is possible to apply time-series of load and generation data to the OPF in a loop, generating optimal network solutions to maintain the network within thermal and voltage limits. The OPF incorporates not only the DG real power output maximisation, but also network loss minimisation as well as minimising the dispatch of DG reactive power. This investigation uses a direct Interior Point (IP) method as the solution methodology which is speed efficient and converges in polynomial time. Each objective function has been assigned a weighting factor, making it possible to favour one objective function and ignore the others. Contributions to enhance the performance of the IP OPF algorithm include a new generic barrier parameter formulation and a new swing bus formulation to model energy export/import in the main optimisation routine. A Terminal Voltage Regulator Mode (TVRM) and Power Factor Regulation Mode (PFRM) for DG were incorporated in the main optimisation routine. The main motivation is to compare these two decentralised DG control methods in terms of the achieving the maximum DG real power generation. The DG operation methods of TVRM and PFRM are compared with the optimisation results obtained from centralised dispatch in terms of the DG capacity achieved as it produces the optimum overall network solution. A suitable value of the droop and local voltage regulator dead-bands were determined for particular DGs. Furthermore, the effect of these decentralised DG control methods on distribution network losses are considered in a measure to assess the financial implications from a DNO's perspective

Dynamic modeling, stability analysis, and controller design for DC distribution systems

The dc distribution systems or dc microgrids are known to be best suited for integration of renewable energy sources into the current power grid and are considered to be the key enabling technology for the development of future smart grid. Dc microgrids also benefit from better current capabilities of dc power lines, better short circuit protection, and transformer-less conversion of voltage levels, which result in higher efficiency, flexibility, and lower cost. While the idea of using a dc microgrid to interface distributed energy sources and modern loads to the power grid seems appealing at first, several issues must be addressed before this idea can be implemented fully. The configuration, stability, protection, economic operation, active management, and control of future dc microgrids are among the topics of interest for many researchers. The purpose of this dissertation is to investigate the dynamic behavior and stability of a future dc microgrid and to introduce new controller design techniques for the Line Regulating Converters (LRC) in a dc distribution system. Paper I is devoted to dynamic modeling of power converters in a dc distribution system. The terminal characteristics of tightly regulated power converters which are an important factor for stability analysis and controller design are modeled in this paper. Paper II derives the simplified model of a dc distribution system and employs the model for analyzing stability of the system. Paper III introduces two controller design methods for stabilizing the operation of the LRC in presence of downstream constant power loads in a dc distribution system. Paper IV builds upon paper III and introduces another controller design method which uses an external feedback loop between converters to improve performance and stability of the dc grid. --Abstract, page iv

Prophet Muhammad (PBUH) in the Holy Quran and Nahj al-Balaghah, and the first volume of the interpretation of Zamakhshari's

The Prophet of Islam, the Prophet Muhammad (PBUH), is the chosen servant of God, the last of the prophets of the divine religion, the teacher of the verses of wisdom, and the trainer and assistant of human beings. When ignorance and darkness shone in Hejaz, he was summoned from the kingdom of heaven to earth. The most divine angel became earthly and spent all his life with his blessing, filled with many ups and downs, in the direction of guidance of the people and the invitation to the religion of Islam, and with the worship and servitude of the essence of the right to the highest degree of worship and highest peak of humanity.In the Holy Qur'an, the eternal miracle of the great Prophet Muhammad that has always been regarded as the book of human guidance, the Prophet (PBUH) has been very much spoken of. The obedience of the Prophet has been raised along with obedience to God. The persecution and disrespect of the Prophet (PBUH) has been as painful a as torment and damnation of God in this world and the world after, and God's friendship is conditional upon obedience to the Prophet (PBUH). The Divine conduct of the Holy Prophet (peace be upon him) and his mercy and patience are described as the coherence and unity of Muslims and is described by the interpretation of "Surely, you (Prophet Muhammad) are of a great morality"[1]. According to the verses of the Holy Qur'an, which includes more than 500 verses, the existence of the Prophet of Islam (PBUH) is a favor to humanity, a mercy for the universe, an eternal pattern for the human race, and a witness to all the divine prophets. The commander of the believers, Imam Ali, who had always been with the Prophet since childhood, in the valuable book of Nahj al-Balaghah portrays various stages of the Prophet’s life during various sermons and speaks of the greatness of the Prophet (PBUH).This study has tried to survey the ethics and behavior of the Holy Prophet (PBUH) in the holy books of the Holy Qur'an and Nahj al-Balaghah, as well as the interpretation of Zamakhshari's Al–Kashshaaf, and there verses, sermons and commentaries in this field have been pointed out. Although no one can claim that this unique personality of the universe has been known to him completely and comprehensibly, so that he can write his knowledge about the Prophet. DOI: 10.7176/RHSS/9-12-12 Publication date:June 30th 2019 [1] http://parsquran.com/data/show.php?sura=68&ayat=4&user=far&lang=eng&tran=

Classification of Epileptic EEG Signals by Wavelet based CFC

Electroencephalogram, an influential equipment for analyzing humans activities and recognition of seizure attacks can play a crucial role in designing accurate systems which can distinguish ictal seizures from regular brain alertness, since it is the first step towards accomplishing a high accuracy computer aided diagnosis system (CAD). In this article a novel approach for classification of ictal signals with wavelet based cross frequency coupling (CFC) is suggested. After extracting features by wavelet based CFC, optimal features have been selected by t-test and quadratic discriminant analysis (QDA) have completed the Classification.Comment: Electroencephalogram; Wavelet Decomposition; Cross Frequency Coupling;Quadratic Discriminant Analysis; T-test Feature Selectio