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distributed-generation
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Robust restoration of distribution systems considering DG units and direct load control programs
, Article Turkish Journal of Electrical Engineering and Computer Sciences ; Volume 26, Issue 5 , 2018 , Pages 2676-2687 ; 13000632 (ISSN) ; Fotuhi Firuzabad, M ; Sharif University of Technology
Turkiye Klinikleri Journal of Medical Sciences
2018
Abstract
This paper presents a new method for restoration of distribution networks after a fault occurrence. This problem is solved from the viewpoint of the distribution system operator with the main goal of minimizing the operating cost during the fault clearance period. The effects of distributed generation (DG) units and direct load control (DLC) programs are considered in designing the proposed restoration procedure. Moreover, the uncertainties associated with the predicted loads of different nodes and the availability of DG are modeled here. Robust optimization is used to model the uncertainties of restoration problems and manage their associated risks. Finally, a robust reconfiguration plan is...
A multi-objective framework for energy resource scheduling in active distribution networks
, Article International Journal of Ambient Energy ; 2018 , Pages 1-13 ; 01430750 (ISSN) ; Ghazi, R ; Moeini Aghtaie, M ; Sharif University of Technology
Taylor and Francis Ltd
2018
Abstract
Purpose: The purpose of this paper is to investigate the impacts of electric vehicles' (EVs) charging/discharging decisions in energy resources scheduling problem of active distribution networks. Design/methodology/approach: The problem under study is modelled as a two-stage optimisation problem in which the main requirements of EV owners are introduced as an objective function of the first stage. The total energy costs and the emission factor are considered as the main criteria of the second stage. The output generation schedules of distributed generation (DG) technologies together with the charging/discharging schedule of EVs are proposed as decision variables of the energy scheduling...
A multi-objective framework for energy resource scheduling in active distribution networks
, Article International Journal of Ambient Energy ; Volume 40, Issue 5 , 2019 , Pages 504-516 ; 01430750 (ISSN) ; Ghazi, R ; Moeini Aghtaie, M ; Sharif University of Technology
Taylor and Francis Ltd
2019
Abstract
Purpose: The purpose of this paper is to investigate the impacts of electric vehicles' (EVs) charging/discharging decisions in energy resources scheduling problem of active distribution networks. Design/methodology/approach: The problem under study is modelled as a two-stage optimisation problem in which the main requirements of EV owners are introduced as an objective function of the first stage. The total energy costs and the emission factor are considered as the main criteria of the second stage. The output generation schedules of distributed generation (DG) technologies together with the charging/discharging schedule of EVs are proposed as decision variables of the energy scheduling...
Day-ahead resource scheduling in distribution networks with presence of electric vehicles and distributed generation units
, Article Electric Power Components and Systems ; Volume 47, Issue 16-17 , 2019 , Pages 1450-1463 ; 15325008 (ISSN) ; Ghazi, R ; Moeini Aghtaie, M ; Sharif University of Technology
Taylor and Francis Inc
2019
Abstract
In this paper a new framework for scheduling of available resources in the distribution networks is developed. In this respect attempts are focused on interactions between charging/discharging profiles of electric vehicles (EVs) and output power of distributed generation units. To reach this goal, the proposed framework is designed as a two-stage optimization procedure. In the first stage, the charging/discharging schedules of EVs are extracted running a linear programing optimization problem taking into account the EV users' constraints and requirements. The usage profiles of the DG units, strategy of buying electricity from the market and also the final charging/discharging patterns of the...
A novel management scheme to reduce emission produced by power plants and plug-in hybrid electric vehicles in a smart microgrid
, Article International Journal of Environmental Science and Technology ; Volume 17, Issue 5 , 2020 , Pages 2529-2544 ; Soleymani, S ; Mehdi, E ; Sharif University of Technology
Springer
2020
Abstract
Recently, with the growth and development of distributed generation (DGs) and energy storage systems (ESSs), as well as smart control equipment, microgrids (MGs) have been developed. Microgrids are comprised of a limited number of constitutive parts, including loads, DGs, ESSs, and electric vehicles (EVs). This paper presents a novel scheme to manage active and reactive powers, based on DGs, ESSs, and EVs to reduce the total operation cost including power generation and emission costs. Simultaneous management of active and reactive power makes it possible to consider grid operation constraints together. In the proposed schedule, the vehicles are assumed to be plug-in hybrid electric...
An approach to Volt/Var control in distribution networks with distributed generation
, Article Scientia Iranica ; Volume 12, Issue 1 , 2005 , Pages 34-42 ; 10263098 (ISSN) ; Ranjbar, A. M ; Shirani, A. R ; Sharif University of Technology
Sharif University of Technology
2005
Abstract
Due to deregulation and restructuring in many countries, it is expected that the amount of small-scale generations connected to the distribution networks will increase. So, it is necessary that the impact of these kinds of generators on Volt/Var control should be investigated. This paper presents a new approach to Volt/Var control in distribution systems with Distributed Generation (DG). It has been shown that DG can improve the entire performance of a network system, by means of better control and decreasing losses. In this approach, the Genetic Algorithm (GA) has been used as the optimization method, where the amount of DG and its controlling parameters, the voltage regulators situation,...
Effect of customer demand type on optimization of distributed generation for minimization of energy loss
, Article International Review of Electrical Engineering ; Volume 7, Issue 2 , Oct , 2012 , Pages 4113-4122 ; 18276660 (ISSN) ; Ehsan, M ; Nouri, H ; Sharif University of Technology
Praise Worthy Prize
2012
Abstract
The problem of distributed generation (DG) optimization in distribution systems has normally been assessed by assuming a constant power (real and reactive) load model. Such assumptions may lead to inconsistent and misleading results about loss reduction, DG optimization and other subsequent calculations. In this paper, the effect of different types of demand, e.g. industrial, residential and commercial, and its time varying effects on distribution networks is investigated. Customer demand type is defined by the load model that is voltage dependent and the load patterns from real life hourly demand data. The study shows that by defining the energy loss minimization as the objective function,...
Optimizing operation indices considering different types of distributed generation in microgrid applications
, Article Energies ; Volume 11, Issue 4 , 2018 ; 19961073 (ISSN) ; Mokhtari, H ; Bhattacharya, S ; Sharif University of Technology
MDPI AG
2018
Abstract
The need for independent power generation has increased in recent years, especially with the growing demand in microgrid systems. In a microgrid with several generations of different types and with all kinds of loads of variable nature, an optimal power balance in the system has to be achieved. This optimal objective, which results in minimal energy losses over a specific period of time, requires an optimal location and sizing of the distributed generations (DGs) in a microgrid. This paper proposes a new optimization method in which both optimal location of the DGs and their generation profile according to the load demand profile as well as the type of DG are determined during the life time...
Optimal energy management of a campus microgrid considering financial and economic analysis with demand response strategies
, Article Energies ; Volume 14, Issue 24 , 2021 ; 19961073 (ISSN) ; Muqeet, H. A ; Shehzad, M ; Jamil, M ; Khan, A. A ; Guerrero, J. M ; Sharif University of Technology
MDPI
2021
Abstract
An energy management system (EMS) was proposed for a campus microgrid (μG) with the incorporation of renewable energy resources to reduce the operational expenses and costs. Many uncertainties have created problems for microgrids that limit the generation of photovoltaics, causing an upsurge in the energy market prices, where regulating the voltage or frequency is a challenging task among several microgrid systems, and in the present era, it is an extremely important research area. This type of difficulty may be mitigated in the distribution system by utilizing the optimal demand response (DR) planning strategy and a distributed generator (DG). The goal of this article was to present a...
Scheduling and sizing of campus microgrid considering demand response and economic analysis
, Article Sensors ; Volume 22, Issue 16 , 2022 ; 14248220 (ISSN) ; Shahzad, M ; Javed, H ; Muqeet, H. A ; Akhter, M. N ; Liaqat, R ; Hussain, M. M ; Sharif University of Technology
MDPI
2022
Abstract
Current energy systems face multiple problems related to inflation in energy prices, reduction of fossil fuels, and greenhouse gas emissions which are disturbing the comfort zone of energy consumers and the affordability of power for large commercial customers. These kinds of problems can be alleviated with the help of optimal planning of demand response policies and with distributed generators in the distribution system. The objective of this article is to give a strategic proposition of an energy management system for a campus microgrid (µG) to minimize the operating costs and to increase the self-consuming energy of the green distributed generators (DGs). To this end, a real-time based...
Sustainable solutions for advanced energy management system of campus microgrids: model opportunities and future challenges
, Article Sensors ; Volume 22, Issue 6 , 2022 ; 14248220 (ISSN) ; Javed, H ; Akhter, M. N ; Shahzad, M ; Munir, H. M ; Nadeem, M. U ; Bukhari, S. S. H ; Huba, M ; Sharif University of Technology
MDPI
2022
Abstract
Distributed generation connected with AC, DC, or hybrid loads and energy storage systems is known as a microgrid. Campus microgrids are an important load type. A university campus microgrids, usually, contains distributed generation resources, energy storage, and electric vehicles. The main aim of the microgrid is to provide sustainable, economical energy, and a reliable system. The advanced energy management system (AEMS) provides a smooth energy flow to the microgrid. Over the last few years, many studies were carried out to review various aspects such as energy sustainability, demand response strategies, control systems, energy management systems with different types of optimization...
Probabilistic analysis to analyze uncertainty incorporating copula theory
, Article Journal of Electrical Engineering and Technology ; Volume 17, Issue 1 , 2022 , Pages 61-71 ; 19750102 (ISSN) ; Shahzad, M ; Munir, H. M ; Nawaz, A ; Fahal, N. A. M ; Khan, M. Y. A ; Ahmed, S ; Sharif University of Technology
Korean Institute of Electrical Engineers
2022
Abstract
The emerging trend of distribution generation with existing power system network leads uncertainty factor. To handle this uncertainty, it is a provocation for the power system control, planning, and operation engineers. Although there are numerous techniques to model and evaluate these uncertainties, but in this paper the integration of Copula theory with Improved Latin-hypercube Sampling (ILHS) are incorporated for Probabilistic load Flow (PLF) evaluation. In probabilistic research approaches, the dominant interest is to achieve appropriate modelling of input random variables and reduce the computational burden. To address the said problem, Copula theory is applied to execute the modelling...
A bi-level approach for optimal contract pricing of independent dispatchable DG units in distribution networks
, Article International Transactions on Electrical Energy Systems ; Volume 26, Issue 8 , 2016 , Pages 1685-1704 ; 20507038 (ISSN) ; Rajabi Ghahnavieh, A ; Haghighat, H ; Sharif University of Technology
John Wiley and Sons Ltd
2016
Abstract
Distributed generation (DG) units are increasingly installed in the power systems. Distribution companies (DisCo) can opt to purchase the electricity from DG in an energy purchase contract to supply the customer demand and reduce energy loss. This paper proposes a framework for optimal contract pricing of independent dispatchable DG units considering competition among them. While DG units tend to increase their profit from the energy purchase contract, DisCo minimizes the demand supply cost. Multi-leader follower game theory concept is used to analyze the situation in which competing DG units offer the energy price to DisCo and DisCo determines the DG generation. A bi-level approach is used...
Centralized optimal management of a smart distribution system considering the importance of load reduction based on prioritizing smart home appliances
, Article IET Generation, Transmission and Distribution ; Volume 16, Issue 19 , 2022 , Pages 3874-3893 ; 17518687 (ISSN) ; Haghifam, M. R ; Safdarian, A ; Sharif University of Technology
John Wiley and Sons Inc
2022
Abstract
The distribution system's economic operation is significantly impacted by the management of distributed generation (DG) resources, energy storage (ES), and controllable loads. The paper employs a smart distribution system that incorporates dispatchable and non-dispatchable DG resources, as well as battery storage, in addition to the demand response (DR) scheme. New modelling was performed in hourly steps to achieve the optimal unit commitment. In smart homes, appliances are prioritized and classified into four types: adjustable, interruptible, shiftable, and uncontrollable loads. Load reduction in smart homes is also considered based on load prioritization and customer participation in the...
Relay logic for islanding detection in active distribution systems
, Article IET Generation, Transmission and Distribution ; Volume 9, Issue 12 , August , 2015 , Pages 1254-1263 ; 17518687 (ISSN) ; Amraee, T ; Ranjbar, A. M ; Mozafari, B ; Sharif University of Technology
Institution of Engineering and Technology
2015
Abstract
This study presents a passive model to detect islanding conditions of synchronous distributed generation resources in a distribution network or a microgrid. The proposed approach uses the classification and regression tree algorithm for distinguishing between islanding and non-islanding situations. It utilises the rate of change of frequency (ROCOF) and harmonic content of the equivalent reactance seen at the location of distributed generation as input features for decision tree construction. Indeed the thresholds of the proposed input features are extracted by the decision tree algorithm. The output if-then rules of the decision tree algorithm are then utilised to make a new relay logic for...
Resilience-based framework for switch placement problem in power distribution systems
, Article IET Generation, Transmission and Distribution ; Volume 12, Issue 5 , March , 2018 , Pages 1223-1230 ; 17518687 (ISSN) ; Abbaspour, A ; Fotuhi Firuzabad, M ; Moeini Aghtaie, M ; Sharif University of Technology
Institution of Engineering and Technology
2018
Abstract
Optimal placement of switches can play a key role in providing resilience to power distribution systems against major faults caused by natural disasters. This study presents a resilience-based framework for optimal switch placement in distribution systems being consistent with the expansion plans of distributed generation units. At first, the impact of hurricanes on distribution system components is modelled using the geographic information system of distribution grid and the strength of components against extreme weather-related events. Then, a new resiliency index is proposed to assess the resilience of distribution grids. This index is involved in a mathematical model of the switch...
Financial tools to manage dispatchable Distributed Generation economic risks
, Article International Conference on Smart Energy Grid Engineering, SEGE 2015, 17 August 2015 through 19 August 2015 ; 2015 ; 9781467379328 (ISBN) ; Rajabi-Ghahnavieh, A ; Azad, H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2015
Abstract
Distributed Generation (DG) has received increasing attention during the last decade. Advantage and constraints of DG application are well known to both DG owner and electric utility. Various technologies are available for DG units among them gas GenSet is, in particular, more attractive to the investors as the technology provides the control on DG generation. However, there are various financial risks associated with dispatchable DG units that prohibit wide private investment in such technologies. This paper examines the use of financial tools to manage dispatchable DG economic risks. A comprehensive framework has been proposed to consider various economic risks to DG owner. Suitable models...
Benefits of real-time monitoring to distribution systems: dynamic thermal rating
, Article IEEE Transactions on Smart Grid ; Volume 6, Issue 4 , 2015 , Pages 2023-2031 ; 19493053 (ISSN) ; Degefa, M. Z ; Fotuhi Firuzabad, M ; Lehtonen, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2015
Abstract
With anticipated proliferation of electric vehicles and distributed generations in near future, dynamic thermal rating (DTR) as a tool for unlocking network capacities, is becoming critical for distribution network operators. DTR is gaining a great and still growing focus of attention in today's power industries. However, potential benefits of DTR, although have been envisioned to be significant, have not yet been studied quantitatively. This paper intends to comprehensively assess the potential impacts of DTR on the performance of a realistic Finnish distribution network. For doing so, first a step-by-step procedure is devised. Then, weather data and loading information of circuits in the...
Developing a multi-objective framework for planning studies of modern distribution networks
, Article 2016 International Conference on Probabilistic Methods Applied to Power Systems, PMAPS 2016 - Proceedings, 16 October 2016 through 20 October 2016 ; 2016 ; 9781509019700 (ISBN) ; Jooshaki, M ; Moeini Aghtaie, M ; Fotuhi Firuzabad, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
This paper presents a new framework for planning studies of modern distribution networks. Presence of electric vehicles (EVs) and various technologies of distributed generation (DG) technologies are considered in the studies as two upcoming events of the future systems. In this regard, place and capacity of DG units along with the reinforcement of distribution lines are determined running a multi-objective (MO) optimization algorithm. Total losses of the distribution network along with annualized cost of expansion plans including investment, operation and maintenance costs are introduced as the main criteria which should be optimized in the proposed framework. An effective Posteriori...
A fast and cost-effective control of a three-phase stand-alone inverter
, Article 8th Power Electronics, Drive Systems and Technologies Conference, PEDSTC 2017, 14 February 2017 through 16 February 2017 ; 2017 , Pages 67-72 ; 9781509057665 (ISBN) ; Keikha, O ; Yaghoubi, M ; Tahami, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2017
Abstract
This paper proposes a straightforward control method for voltage control of a three-phase transformer-based inverter in uninterruptible power supplies or distributed generation systems. The approach offers a dual-loop design consisting inner current control loop and outer voltage loop. Sliding mode current controller provides desired bandwidth for voltage controller which consists of a state feedback term for stabilization and resonant term for harmonic damping. The proposed scheme provides fast dynamic response and low total harmonic distortion even for high power inverters with the limitations of switching frequency and LC filter components. Experimental studies for 2KVA linear and...