Development of Optimal Configuration, Modeling and Control of Large Scale PV (PHOTOVOLTAIC) Parks

, M.Sc. Thesis Sharif University of Technology Peyghami Akhooleh, Saeed (Author) ; Parniani, Mostafa (Supervisor)

Abstract

Environmental problems as well as energy sustainability concerns, have forced many countries to provide part of their energy from Renewable Resources (RR). Solar energy has gained a lot of attention because of the huge energy stored in the sun and its availability. Since Energy conversion via PV panels causes less environmental problems, today, hundreds of large-scale PV parks are installed and planned worldwide. Since a single PV panel provides only up to 400 Watts of power, a PV park contains a large number of PV panels. Augmenting this large number of PV panels and converting their output power to AC using DC/DC and DC/AC converters should be in a form that not only the investment cost is...

Hierarchical power sharing control in DC microgrids

, Article Microgrid: Advanced Control Methods and Renewable Energy System Integration ; 2016 , Pages 63-100 ; 9780081012628 (ISBN) Peyghami, S ; Mokhtari, H ; Blaabjerg, F ; Sharif University of Technology

Elsevier Inc 2016

Abstract

Because of the advances in power electronics, DC-based power systems, have been used in industrial applications such as data centers [. 18], space applications [. 10], aircraft [. 12], offshore wind farms, electric vehicles [. 56], DC home systems [. 5, 20], and high-voltage DC transmission systems. To provide such sensitive loads with more reliability, efficiency, and controllability for future power systems, AC microgrid and more recently DC microgrid and smart-grid technologies have been employed [. 5-9].To obtain stable and optimal operation in DC power systems (microgrids), proper load sharing among different energy units and acceptable voltage regulation across the microgrid is...

Autonomous power management in LVDC microgrids based on a superimposed frequency droop

, Article IEEE Transactions on Power Electronics ; 2017 ; 08858993 (ISSN) Peyghami, S ; Mokhtari, H ; Blaabjerg, F ; Sharif University of Technology

2017

Abstract

In this paper a novel droop approach for autonomous power management in low voltage dc microgrids based on a master-slave concept is presented. Conventional voltage-based droop approaches suffer from poor power sharing due to line resistance effects on a virtual resistance, which is solved a by introducing a communication system to increase the current sharing accuracy. In this paper, a virtual frequency is superimposed by the master units, and slave units determine their output power according to the corresponding frequency-based droop characteristics. Unlike the voltage-droop methods, the proposed virtual frequency-droop approach can be applied for proportional power management among the...

Autonomous power management in LVDC microgrids based on a superimposed frequency droop

, Article IEEE Transactions on Power Electronics ; Volume 33, Issue 6 , 2018 , Pages 5341-5350 ; 08858993 (ISSN) Peyghami, S ; Mokhtari, H ; Blaabjerg, F ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2018

Abstract

In this paper, a novel droop approach for autonomous power management in low voltage DC (LVDC) microgrids based on a master-slave concept is presented. Conventional voltage-based droop approaches suffer from poor power sharing due to line resistance effects on a virtual resistance, which is solved by introducing a communication system to increase the current sharing accuracy. In this paper, a virtual frequency is superimposed by the master units, and slave units determine their output power according to the corresponding frequency-based droop characteristics. Unlike the voltage-droop methods, the proposed virtual frequency-droop approach can be applied for proportional power management among...

Autonomous operation of a hybrid AC/DC microgrid with multiple interlinking converters

, Article IEEE Transactions on Smart Grid ; Volume 9, Issue 6 , 2018 , Pages 6480-6488 ; 19493053 (ISSN) Peyghami, S ; Mokhtari, H ; Blaabjerg, F ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2018

Abstract

Applying conventional dc-voltage-based droop approaches for hybrid ac/dc microgrids interconnected by a single interlinking converter (IC) can properly manage the power flow among ac and dc subgrids. However, due to the effect of line resistances, these approaches may create a circulating power as well as overstressing the ICs in the case of employing multiple ICs for interconnecting the ac and dc subgrids. This paper proposes an autonomous power sharing approach for hybrid microgrids interconnected through multiple ICs by introducing a superimposed frequency in the dc subgrid. Hence, a suitable droop approach is presented to manage the power among the dc and ac sources as well as ICs. The...

Decentralized load sharing in a low-voltage direct current microgrid with an adaptive droop approach based on a superimposed frequency

, Article IEEE Journal of Emerging and Selected Topics in Power Electronics ; Volume 5, Issue 3 , 2017 , Pages 1205-1215 ; 21686777 (ISSN) Peyghami, S ; Mokhtari, H ; Blaabjerg, F ; Sharif University of Technology

2017

Abstract

Conventional droop methods for load sharing control in low-voltage direct current microgrids suffer from poor power sharing and voltage regulation, especially in the case when operating many dc sources with long feeders. Hence, the communication-based approaches are employed to improve the load sharing accuracy and voltage regulation. To avoid using such an infrastructure and the corresponding effects on the reliability and stability, an adaptive droop controller based on a superimposed frequency is proposed in this paper. Load sharing accuracy is improved by adapting the droop gains utilizing an introduced ac power. The secondary controller locally estimates and compensates the voltage drop...

A multi-objective optimal power management strategy for enhancement of battery and propellers lifespan in all-electric ships

, Article Journal of Energy Storage ; Volume 65 , 2023 ; 2352152X (ISSN) Nasiri, S ; Parniani, M ; Peyghami, S ; Sharif University of Technology

Elsevier Ltd 2023

Abstract

This paper proposes a multi-objective optimum approach for the participation of the propulsion system in mitigating the All-Electric Ship (AES) power system fluctuations. This strategy optimally balances the propellers torque/speed change and the energy storages charge/discharge rate to obtain an economically-efficient operating point. The method aims to minimize the propeller mechanical fatigue and the battery loss of life (LoL) according to their investment costs, while other operational constraints are considered. For this purpose, a novel index, called the Propulsion System Cooperation Coefficient (PSCC), is developed. This index adjusts the magnitude of the propeller speed/torque...

Reliability evaluation in microgrids with non-exponential failure rates of power units

, Article IEEE Systems Journal ; Volume 14, Issue 2 , 2020 , Pages 2861-2872 Peyghami, S ; Fotuhi Firuzabad, M ; Blaabjerg, F ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2020

Abstract

This article explores the impacts of non-exponentially distributed failures on reliability of microgrids. Failure rate of some components such as power electronic converters is not constant, while they play a major role in microgrids. Consequently, their failure characteristics will affect the microgrid reliability. Hence, the conventional reliability evaluation approaches based on mean time to failure may introduce inaccurate inputs for decision making in planning and operation of microgrids. In this article, different approaches are employed for evaluating the reliability of microgrids with non-constant failure rates. The obtained results indicate that the system reliability remarkably...

Model-based Reliability-Centered design of power electronics dominated microgrids

, Article 17th International Conference on Probabilistic Methods Applied to Power Systems, PMAPS 2022, 12 June 2022 through 15 June 2022 ; 2022 ; 9781665412117 (ISBN) Peyghami, S ; Blaabjerg, F ; Fotuhi Firuzabad, M ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2022

Abstract

This paper proposes a model-based design approach for microgrids considering the aging of power electronic devices under different operating conditions. The proposed approach takes into account the physics of failure mechanisms in converter components as the failure prone devices in power systems. Furthermore, it considers the impacts of load profile on the aging of converter components and system performance. This approach facilitates accurate and optimized design of power electronic-based microgrids. According to this approach fragile links of power converters for a specified application can be identified. Moreover, the weakest converters based on their function in the microgrid can be...

Active damping of torsional vibrations due to the sub-harmonic instability on a synchronous generator

, Article 20th European Conference on Power Electronics and Applications, EPE 2018 ECCE Europe, 17 September 2018 through 21 September 2018 ; 2018 ; 9789075815283 (ISBN) Peyghami, S ; Azizi, A ; Mokhtari, H ; Blaabjerg, F ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2018

Abstract

Sub-harmonic stability issues due to the interaction between a load-commutated motor drive and a synchronous turbo-generator train in a Liquefied Natural Gas (LNG) station are studied in this paper. The sub-harmonic current injected by motor drives may excite the mechanical torsional modes of turbogenerator train. In this paper, the electro-mechanical interaction phenomenon is investigated and an active damper is proposed to absorb the sub-harmonic currents of motor drives and increase the damping of the electro-mechanical system. Simulations and experiments validate the instability problem and effectiveness of the proposed solution. © 2018 EPE Association

Decentralized droop control in DC microgrids based on a frequency injection approach

, Article IEEE Transactions on Smart Grid ; Volume 10, Issue 6 , 2019 , Pages 6782-6791 ; 19493053 (ISSN) Peyghami, S ; Davari, P ; Mokhtari, H ; Blaabjerg, F ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2019

Abstract

Power sharing control among grid forming dc sources employing a conventional voltage droop approach meets inaccurate load sharing and unacceptable voltage regulation performance. Thereby, communication-based secondary and supervisory controllers have been presented to overcome the aforementioned issues. Furthermore, with the aim of eliminating communication system, frequency-based droop approaches have been introduced for low-voltage dc grids where the frequency of the superimposed ac signal onto the dc voltage is proportional to the output power. However, in reality, dc grid structures can be applied to medium and high voltage applications with different X/R ratios. This paper generalizes...

A nonmonotone PRP conjugate gradient method for solving square and under-determined systems of equations

, Article Computers and Mathematics with Applications ; Volume 73, Issue 2 , 2017 , Pages 339-354 ; 08981221 (ISSN) Ataee Tarzanagh, D ; Nazari, P ; Peyghami, M. R ; Sharif University of Technology

Elsevier Ltd 2017

Abstract

In this paper, we propose a new derivative-free preconditioned conjugate gradient method in order for solving large-scale square and under-determined nonlinear systems of equations. The proposed method is also equipped with a relaxed nonmonotone line search technique. Under some suitable assumptions, the global convergence property is established. Numerical results on some square and under-determined test systems show the efficiency and effectiveness of the new method in practice. An application of the new method for solving nonlinear integro-differential equations is also provided. © 2016 Elsevier Ltd

Extended reduced rank two Abaffian update schemes in the ABS-type methods

, Article Applied Mathematics and Computation ; Volume 185, Issue 1 , 2007 , Pages 255-265 ; 00963003 (ISSN) Amini, K ; Mahdavi Amiri, N ; Peyghami, M. R ; Sharif University of Technology

2007

Abstract

The ABS methods, introduced by Abaffy, Broyden and Spedicato, are direct iteration methods for solving a linear system where the ith iterate satisfies the first i equations, therefore a system of m equations is solved in at most m steps. Recently, we have presented a new approach to devise a class of ABS-type methods for solving full row rank systems [K. Amini, N. Mahdavi-Amiri, M. R. Peyghami, ABS-type methods for solving full row rank linear systems using a new rank two update, Bulletin of the Australian Mathematical Society 69 (2004) 17-31], the ith iterate of which solves the first 2i equations. Here, to reduce the space and computation time, we use a new extended rank two update formula...

Analysis of all-electric ship motions impact on PV system output power in waves

, Article 2022 IEEE Transportation Electrification Conference and Expo, ITEC 2022, 15 June 2022 through 17 June 2022 ; 2022 , Pages 450-455 ; 9781665405607 (ISBN) Nasiri, S ; Parniani, M ; Blaabjerg, F ; Peyghami, S ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2022

Abstract

Waves encountering can cause significant ship motions and affect the photovoltaic power generation capacity in All-Electric Ships (AES) during extreme conditions. In this paper, a comprehensive strategy is proposed to examine the impact of modern vessels' movements on the PV system output and the ship power quality during various operating scenarios. The proposed theoretical model-based technique determines ship angles in a wave collision and assesses sun-related angles concerning the vessel motions. Based on the panel angles, the solar irradiance and the PV system power variations can be derived. The developed method can simultaneously evaluate the effect of ship motions on the photovoltaic...

Decentrilized Power Management in AC-DC Hybrid Microgirds

, Ph.D. Dissertation Sharif University of Technology Peyghami, Saeed (Author) ; Mokhtari, Hossein (Supervisor) ; Blaabjerg, Frede (Co-Advisor)

Abstract

Proliferation of Distributed Generations (DGs) introduces higher reliability, stability, and quality as well as lower power losses and operational costs to the power systems. Integrating smart-grid and microgrid technologies to the power systems will further improve the overall performance of the system. Moreover, DC microgrids create an infrastructure to supply DC loads by DC sources such as photovoltaic arrays, fuel cell modules, as well as storages, which in case, increases the energy conversion efficiency. Operating DC microgrids together with AC microgrids, therefore, will form a new distrib-ution system called hybrid AC/DC systems, in which the DC side is dynamically decoupled from the...

Standard test systems for modern power system analysis: an overview

, Article IEEE Industrial Electronics Magazine ; Volume 13, Issue 4 , 2019 , Pages 86-105 ; 19324529 (ISSN) Peyghami, S ; Davari, P ; Fotuhi Firuzabad, M ; Blaabjerg, F ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2019

Abstract

The reliable design, planning, and operation of power systems are of paramount importance for providing reliable services to customers. This article reviews the different aspects of power system reliability, ranging from planning to operation. Standard benchmarks employed for power system studies are reviewed according to nearly 2,500 IEEE journal papers from 1986 to early 2019. Our overview provides the pros and cons of existing test systems, implying the lack of appropriate benchmarks for future power system studies, including renewable resources and modern technologies. Furthermore, this article presents requirements for updating and modifying the benchmarks for modern power systems...

Failure mode, effects and criticality analysis (FMECA) in power electronic based power systems

, Article 21st European Conference on Power Electronics and Applications, EPE 2019 ECCE Europe, 3 September 2019 through 5 September 2019 ; 2019 ; 9789075815313 (ISBN) Peyghami, S ; Davari, P ; F. Firuzabad, M ; Blaabjerg, F ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2019

Abstract

Power electronics is becoming an underpinning technology for modern power systems. Power converters are increasingly used in various applications implying different levels of importance in power systems. Hence, optimal decision-making for manufacturing, control, operation and maintenance of them requires understanding of their importance in the power systems. Furthermore, identifying the converters importance may be beneficial for simplifying the system-level reliability modeling in a large Power Electronic based Power Systems (PEPSs). Thereby, a Failure Mode, Effects and Criticality Analysis (FMECA) approach is proposed in this paper in order to figure out the importance of converters in...

Distributed secondary control in DC microgrids with low-bandwidth communication link

, Article 7th Power Electronics, Drive Systems and Technologies Conference, PEDSTC 2016, 16 February 2016 through 18 February 2016 ; 2016 , Pages 641-645 ; 9781509003754 (ISBN) Loh, P. C ; Blaabjerg, F ; Peyghami Akhuleh, S ; Mokhtari, H ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2016

Abstract

In this paper, a distributed secondary power sharing approach with low bandwidth communication network is proposed for low voltage direct current (LVDC) microgrids. Conventional droop control causes voltage drop in the grid and also a mismatch on the current of converters in the case of consideration of the line resistances. Proposed control system carry out the current value of the other converters to reach the accurate current sharing and suitable voltage regulation as well. Voltage and current controllers locally regulate the voltage and current of converters as a secondary controller. Secondary controller is realized locally and the communication network is only used to transfer the data...

On-line condition monitoring system for dc-link capacitor of back-to-back converters using large-signal transients

, Article IEEE Journal of Emerging and Selected Topics in Power Electronics ; 2022 ; 21686777 (ISSN) Ghadrdan, M ; Abdi, B ; Peyghami, S ; Mokhtari, H ; Blaabjerg, F ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2022

Abstract

The increasing use of power electronic equipment and the importance of their continuous and correct operation have attracted remarkable attention to the condition monitoring of power electronic converters. Since capacitors are the leading cause of power electronic converters failure, this paper attempts to attain a solution to monitor the condition of the DC-link capacitor in a three-phase back-to-back converter using the stimulated measurable transients. The proposed method works based on the temporary change of switching logic and the measurement of the DC-link voltage and converter input phase current transients. By processing the measured signals, the capacitance of the capacitor is...

On-Line condition monitoring system for dc-link capacitor of back-to-back converters using large-signal transients

, Article IEEE Journal of Emerging and Selected Topics in Power Electronics ; Volume 11, Issue 1 , 2023 , Pages 1132-1142 ; 21686777 (ISSN) Ghadrdan, M ; Abdi, B ; Peyghami, S ; Mokhtari, H ; Blaabjerg, F ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2023

Abstract

The increasing use of power electronic equipment and the importance of their continuous and correct operation have attracted remarkable attention to the condition monitoring of power electronic converters. Since capacitors are the leading cause of power electronic converters failure, this article attempts to attain a solution to monitor the condition of the dc-link capacitor in a three-phase back-to-back converter using the stimulated measurable transients. The proposed method works based on the temporary change of switching logic and the measurement of the dc-link voltage and converter input phase current transients. By processing the measured signals, the capacitance of the capacitor is...