Power Electronic
H. Chaudhari; P. Darji
Abstract
Recent grid codes require a high voltage direct current (HVDC) converter station remains connected and provide reliable operation under various faults. An improved clamp-double submodule (CD-SM) is introduced in this article, which belongs to the modular multilevel converter (MMC) topologies proposed ...
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Recent grid codes require a high voltage direct current (HVDC) converter station remains connected and provide reliable operation under various faults. An improved clamp-double submodule (CD-SM) is introduced in this article, which belongs to the modular multilevel converter (MMC) topologies proposed for high voltage direct current (HVDC) systems. The proposed submodule (SM) topology features a reduced number of control switches, lower converter level faults, and DC fault-blocking capability compared to the conventional submodule topologies. A CD-SM consists of five $IGBT$s, two diodes, and two floating capacitors, where capacitor voltages are maintained according to the binary geometric propagation (GP) ratio which enables it to generate a maximum four-level output voltage. The hybrid pulse width modulation (PWM) technique is used to generate desired switching pulses for a converter and the associated voltage balancing control technique maintains the power exchange between the converters. In this article, the dimensioning of the proposed MMC converter, and its performance under different fault conditions is discussed in detail. Further, a quantitative comparison with other submodule topologies in terms of dc fault-blocking capability, output voltage level, and device count is discussed. Simulation in MATLAB/Simulink and their results validate the effectiveness of the proposed topology for MMC based HVDC system.
H. Radmanesh; M. Saeidi
Abstract
In this paper, a distributed generation including diesel generators, wind turbines, and microturbines are introduced, and their mathematical model is described using the Taylor expansion method. With the goal of computational complexity eliminating, the reduced order model (ROM) of microgrid components ...
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In this paper, a distributed generation including diesel generators, wind turbines, and microturbines are introduced, and their mathematical model is described using the Taylor expansion method. With the goal of computational complexity eliminating, the reduced order model (ROM) of microgrid components is considered. The results of the studies indicate that the microgrid frequency is unstable. The main purpose of this paper is stabilizing the frequency of the microgrid by design modified linear controller. It is shown that the using proposed linear controller increases the dynamic response of the diesel generator and therefore can be constituted stable microgrid. The results show that the diesel generator can control the frequency of the microgrid in unwanted islanding and load change conditions. To verify the validity and feasibility of the proposed controller, several simulations results have been presented on MATLAB/Simulink software. The simulation results show the appropriate performance of the proposed controller for example in islanding mode, frequency restoration time is less than 1 (s) by using the proposed controller, as a result, the microgrid can be exploited in island mode.
Planing & Reliability
A. Ghaedi; M. Mahmoudian; R. Sedaghati
Abstract
In recent years, due to rising social welfare, the reliability has become one of most important topics of modern power network and electricity companies try to provide the electric power to the consumers with minimal interruptions. For this purpose, the electricity companies to improve the reliability ...
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In recent years, due to rising social welfare, the reliability has become one of most important topics of modern power network and electricity companies try to provide the electric power to the consumers with minimal interruptions. For this purpose, the electricity companies to improve the reliability of the power system can utilize different techniques. In this paper, new developments occurred in electricity industry including integration of large-scale renewable resources, integration of large capacity energy storage systems, integration of combined heat and electricity units into power network and demand side response plans are taken into account, and these events impact on power network reliability is assessed. Power networks are affected with integration of renewable resources. Multi-state reliability models for renewable generation plants are obtained, in the paper. Suitable number of states in the proposed reliability model is selected by calculating XB index. Besides, fuzzy c-means clustering approach is utilized for determining probability of states. For study impact of energy storage systems with large capacity on power network reliability, load model is modified. To investigate effect of combined heat and power plants on power network reliability, failure of composed elements and produced thermal power are considered in reliability model of these plants. To evaluate demand side response impact on reliability of power network, the load model is modified. The effectiveness of the proposed techniques on the reliability enhancement of power network is satisfied using numerical results performed on reliability test systems based on the suggested methods.
Energy Management
E. Shahryari; H. Shayeghi; B. Mohammadi-ivatloo; M. Moradzadeh
Abstract
Recently, economic and environmental problems have created a strong attitude toward utilizing renewable energy sources (RESs). Nevertheless, uncertainty of wind and solar power leads to a more complicated energy management (EM) of RESs in microgrids. This paper models and solves the EM problem of microgrid ...
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Recently, economic and environmental problems have created a strong attitude toward utilizing renewable energy sources (RESs). Nevertheless, uncertainty of wind and solar power leads to a more complicated energy management (EM) of RESs in microgrids. This paper models and solves the EM problem of microgrid from the generation point of view. To do this, mathematical formulation of a grid- connected microgrid including wind turbine (WT), photovoltaic (PV), micro turbine (MT), fuel cell (FC) and energy storage system (ESS) is presented. Furthermore an improved incentive-based demand response program (DRP) is applied in microgrid EM problem to flatten the load pattern. Comprehensive studying of EM in both intra-day and day-ahead markets is another contribution of this paper. However, the main novelty of this paper is proposing a new uncertainty modeling technique which is based on copula function and scenario generation. This paper tries to optimize operational cost and environmental pollution as the objective functions and solve them using group search optimization (GSO) algorithm. Numerical results approve the efficiency of the proposed method in solving microgrid EM problem.
Power System Stability
F. Babaei; A. Safari; J. Salehi; H. Shayeghi
Abstract
Although the presence of clean energy resources in power systems is required to reduce greenhouse gas emissions, system security faces severe challenges due to its increased intelligence and expansion, as well as the high penetration of renewable energy resources. According to new operating policies, ...
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Although the presence of clean energy resources in power systems is required to reduce greenhouse gas emissions, system security faces severe challenges due to its increased intelligence and expansion, as well as the high penetration of renewable energy resources. According to new operating policies, power systems should withstand subsequent single contingencies. Also, the effect of electrical and structural characteristics must be considered in power system security assessment. Thus, this paper introduces a comprehensive risk-based approach that quantifies the impact of contingency-induced variation in topology by using complex network theory metrics. Then, it identifies elements that surpass security limitations and eliminates them to execute cascading outage analysis via AC power flow. Lastly, wind power uncertainty and contingency probability are multiplied by the linear combination of electrical and structural consequences, and security status is assigned to each contingency based on its risk value. Additionally, simulations are carried out on modified 118 and 300 bus IEEE systems, and the extensive results are utilized to demonstrate the effectiveness of the proposed methodology.
Energy Management
M. Mohebbi-Gharavanlou; S. Nojavan; K. Zareh
Abstract
Virtual power plant (VPP) can be studied to investigate how energy is purchased or sold in the presence of electricity market price uncertainty. The VPP uses different intermittent distributed sources such as wind turbine, flexible loads, and locational marginal prices (LMPs) in order to obtain profit. ...
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Virtual power plant (VPP) can be studied to investigate how energy is purchased or sold in the presence of electricity market price uncertainty. The VPP uses different intermittent distributed sources such as wind turbine, flexible loads, and locational marginal prices (LMPs) in order to obtain profit. VPP should propose bidding/offering curves to buy/sell from/to day-ahead market. In this paper, robust optimization approach is proposed to achieve the optimal offering and bidding curves which should be submitted to the day-ahead market. This paper uses mixed-integer linear programming (MILP) model under GAMS software based on robust optimization approach to make appropriate decision on uncertainty to get profit which is resistance versus price uncertainty. The offering and bidding curves of VPP are obtained based on derived data from results. The proposed method, due to less computing, is also easy to trace the problem for the VPP operator. Finally, the price curves are obtained in terms of power for each hour, which operator uses the benefits of increasing or decreasing market prices for its plans. Also, results of comparing deterministic and RO cases are presented. Results demonstrate that profit amount in maximum robustness case is reduced 25.91 % and VPP is resisted against day-ahead market price uncertainty.
Distribution Systems
P. Niranjan; N.K. Choudhary; N. Singh; R.K. Singh
Abstract
Conventional overcurrent protection schemes may not be sufficient to provide the complete protection of microgrids, especially in the islanded mode (ISM) of operation. Directional overcurrent relays (DOCRs) in microgrid may malfunction due to significant changes in fault current level and change in topology ...
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Conventional overcurrent protection schemes may not be sufficient to provide the complete protection of microgrids, especially in the islanded mode (ISM) of operation. Directional overcurrent relays (DOCRs) in microgrid may malfunction due to significant changes in fault current level and change in topology from grid-connected mode (GCM) to ISM. The novel contribution of this study is to determine the optimal settings of time-voltage-current-based dual-setting DOCRs with mixed inverse characteristics, valid in both GCM and ISM, without any miscoordination of relay pairs. The relay coordination problem is formulated as a mixed integer non-linear programming (MINLP) problem and optimally solved using an improved environmental adaption method (IEAM). The proposed relay coordination scheme has been tested on a 7-bus microgrid, the low-voltage section of the modified IEEE-14 bus benchmark system. The performance of the proposed protection scheme has been compared with the existing schemes, considering conventional DOCRs, time-voltage-current-based DOCRs, and dual-setting DOCRs.
A. Torkaman; V. Naeini
Abstract
Turn to turn fault is one of the major internal failures in the power transformers that if it is not quickly detected, can be extended and led to a complete transformer breakdown. So, the diagnosis and location of the turn to turn fault of the power transformer, as one of the most important equipment ...
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Turn to turn fault is one of the major internal failures in the power transformers that if it is not quickly detected, can be extended and led to a complete transformer breakdown. So, the diagnosis and location of the turn to turn fault of the power transformer, as one of the most important equipment in the power system, is the main objective of this paper. For this purpose, a detailed model of a three-phase transformer is presented by the finite element method (FEM) to investigate this fault in the different situations. Accordingly, the number of short-circuit turns as well as fault location, cause to generate the high forces between the short-circuit turns and the other healthy winding turns. Consequently, in this paper an appropriate method based on force analysis of winding turns for detecting, locating and determining fault severity is introduced.
Distribution Systems
F. Jabari; M. Shabanzadeh; M. Zeraati
Abstract
Distribution system state estimation (DSSE) is widely used for real-time monitoring of power grids, where different types of metering devices such as phasor measurement units, smart meters, power quality meters, and etc. are installed. The accuracy of estimated states and the system observability level ...
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Distribution system state estimation (DSSE) is widely used for real-time monitoring of power grids, where different types of metering devices such as phasor measurement units, smart meters, power quality meters, and etc. are installed. The accuracy of estimated states and the system observability level depends on the type, number and location of meters and since there are many nodes and branches in such large networks, a highly redundant measurement infrastructure is practically unattainable due to the limited investment budget. Hence, this paper proposes a novel meter placement algorithm aiming to minimize the distribution system state estimation error and enhance the system observability level considering the limited number of available meters or investment cost. To this end, on one hand, Monte Carlo simulation (MCS) is applied to a weighted least squares (WLS) based DSSE to find the nodal voltage magnitude and angle as the state variables under the uncertainty of measurements. A MCS and WLS-DSSE hybrid iterative nonlinear optimization mesh adaptive direct search (NOMADS) algorithm is proposed to obtain the best locations of the voltage measuring units considering a trade-off between the DSSE performance and the investment cost. The uncertainties associated with the voltage measurements are modeled using random errors with normal probability distribution function. The efficiency and applicability of the proposed method are analyzed by its implementation on a 25-node unbalanced radial distribution system and numerical results demonstrate that this method technically outperforms other heuristic algorithms in the literature which are usually computationally intractable or more demanding in finding the optimal meter places under uncertainties. Compared to other recently developed algorithms, the accuracy of the estimated states as well as the runtime of the proposed algorithm are improved significantly especially under severe measuring errors. Moreover, it is capable to find the minimum number of voltage meters ensuring that the system observability criterion and the expected DSSE accuracy are fulfilled under the uncertain operating conditions.
Evolutionary Computing
M. Dehghani; M. Mardaneh; O. P. Malik
Abstract
These days randomized-based population optimization algorithms are in wide use in different branches of science such as bioinformatics, chemical physics andpower engineering. An important group of these algorithms is inspired by physical processes or entities’ behavior. A new approach of applying ...
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These days randomized-based population optimization algorithms are in wide use in different branches of science such as bioinformatics, chemical physics andpower engineering. An important group of these algorithms is inspired by physical processes or entities’ behavior. A new approach of applying optimization-based social relationships among the members of a community is investigated in this paper. In the proposed algorithm, search factors are indeed members of the community who try to improve the community by ‘following’ each other. FOA implemented on 23 well-known benchmark test functions. It is compared with eight optimization algorithms. The paper also considers for solving optimal placement of Distributed Generation (DG). The obtained results show that FOA is able to provide better results as compared to the other well-known optimization algorithms.
Electric Mechinces & Drive
N. Rostami; A.A. Kadhim; M.B. Bannae-Sharifian
Abstract
Permanent Magnet Linear Synchronous Motors (PMLSMs) suffer from inevitable cogging force, especially in low-speed applications. In this paper, a new PMLSM is presented that uses segmented magnets instead of typically used rectangular magnets. This results in a significant reduction in cogging force and ...
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Permanent Magnet Linear Synchronous Motors (PMLSMs) suffer from inevitable cogging force, especially in low-speed applications. In this paper, a new PMLSM is presented that uses segmented magnets instead of typically used rectangular magnets. This results in a significant reduction in cogging force and improved back EMF waveform. However, with these types of magnets, the actual three-dimensional (3D) structure of the machine cannot be reduced to a 2D problem because the thickness of the magnets varies with the depth of the device. Although 3D Finite Element Analysis (FEA) can be used, this method is very time-consuming even for one calculation step, which makes it difficult to use in optimization processes. To overcome these challenges, quasi-3D approach is used to transform the actual 3D structure of the machine into several 2D models and find the overall performance by combining the results obtained for each 2D problem. Genetic algorithm combined with quasi-3D method is used to find the appropriate thickness of each PM segment.
Power System Operation
S. Ghaderi; H. Shayeghi; Y. Hashemi
Abstract
In this paper, a model for hybrid transmission expansion planning (TEP) and reactive power planning (RPP) considering demand response (DR) model has been presented. In this study RPP considered by TEP for its effects on lines capacity and reduction of system expansion costs. On the other hand the expansion ...
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In this paper, a model for hybrid transmission expansion planning (TEP) and reactive power planning (RPP) considering demand response (DR) model has been presented. In this study RPP considered by TEP for its effects on lines capacity and reduction of system expansion costs. On the other hand the expansion of the transmission system is an important subject, especially dealing with the new issues of smart networks like as demand response. Demand response program can change the network expansion planning by shifting elasticity loads and reducing of peak load to improve conditions and decrease the costs. To combine demand response model into the transmission expansion planning and reactive power planning, nonlinear mixed integer meta-heuristic optimization algorithm is used. To evaluate the impact of the proposed expansion planning, this model is exerted to the 30-bus test system. Simulation outcomes display the proposed technique considering demand response model reduces the overall cost of the hybrid TEP-RPP.
Power System Stability
V.M. Dholakiya; B.N. Suthar
Abstract
This research verifies Frequency-Linked Pricing (FLP)-based operating strategies under an availability-based tariff (ABT) for automatic generation control (AGC) of multisource power systems with nonlinearity and interconnections via AC/DC Tie-Lines. Through modeling and simulation in Matlab/Simulink, ...
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This research verifies Frequency-Linked Pricing (FLP)-based operating strategies under an availability-based tariff (ABT) for automatic generation control (AGC) of multisource power systems with nonlinearity and interconnections via AC/DC Tie-Lines. Through modeling and simulation in Matlab/Simulink, this study also identifies a comparatively superior and more appropriate FLP-based operating strategy for AGC under ABT. Different ABT operating techniques yield Generating Control Error (GCE) by combining unscheduled interchange (UI) charges corresponding to frequency deviation and the marginal cost of generation. Three FLP-based operating strategies are compared to standard operating strategies. In addition, several load pattern scenarios are analyzed to ensure a suitable FLP-based operational strategy. The economic accounting associated with UI pricing for FLP-based operational strategies has been analyzed. The outcomes demonstrate that the operational approach that compares actual UI charges and marginal expenses to their respective reference values excels relatively well.
Micro Grid
M. Shahparasti; P. Teimourzadeh Baboli
Abstract
In this paper, an adaptive control strategy is proposed for the inverters of renewable energy source (RES) to simultaneously control the load voltage, grid current and the amount of instantaneous injected power to the grid in the presence of grid voltage distortions and nonlinearity of load current. ...
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In this paper, an adaptive control strategy is proposed for the inverters of renewable energy source (RES) to simultaneously control the load voltage, grid current and the amount of instantaneous injected power to the grid in the presence of grid voltage distortions and nonlinearity of load current. In the proposed control strategy, the power quality of the local load can be settled based on the operator command. In order to implement the proposed control strategy, a cascaded framework of power, voltage and current control has been introduced. An efficient and fast response controller is introduced for the voltage loop, aiming to compensate of harmonics without any complex calculations. The proposed cascade framework is simulated with nonlinear load and non-ideal grid conditions. The simulation results show the effectiveness of the proposed control strategy to not only supply the local load on an appropriate voltage and current quality but also maintaining the amount of injected power at the operator’s desired level.
Power Electronic
N. Yousefi; D. Mirabbasi; B. Alfi; M. Salimi; Gh.R. Aghajani
Abstract
This report develops a high step-up topology employing a voltage multiplier cell (VMC) and a coupled inductor for renewable energy usage. The efficiency is improved and the blocking voltage on semiconductors is decreased. The proposed structure achieves a high voltage gain by utilizing a VMC and one ...
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This report develops a high step-up topology employing a voltage multiplier cell (VMC) and a coupled inductor for renewable energy usage. The efficiency is improved and the blocking voltage on semiconductors is decreased. The proposed structure achieves a high voltage gain by utilizing a VMC and one coupled inductor. This structure employs only one MOSFET switch, lowering the cost of the converter. Further benefits are the reduced number of components and the low blocking voltage of the switches/diodes. Furthermore, the VMC functions as a clamp circuit, reducing the peak voltage of the switch. Consequently, in the presented converter, a low nominal voltage MOSFET can be operated. The switching modes, steady-state analysis, and comparative study with other comparable converters demonstrate the converter's performance and superiority. A 200W laboratory scale operating under the 25kHz switching frequency and a voltage conversion of 20V~150V is built to validate the theoretical equations. The proposed converter efficiency at the full load is about 96.3%. Also, the normalized maximum voltage stress on switch and diodes for duty cycle D=0.6 and turn ratio N=2 is about 0.33 and 0.8, respectively.
Distribution Systems
P. Salyani; J. Salehi
Abstract
The reliability of distribution networks is inherently low due to their radial nature, consequently distribution companies (DisCos) usually seek to improve the system reliability indices with the minimum possible investment cost. This can be known as system-oriented reliability planning (SORP). However, ...
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The reliability of distribution networks is inherently low due to their radial nature, consequently distribution companies (DisCos) usually seek to improve the system reliability indices with the minimum possible investment cost. This can be known as system-oriented reliability planning (SORP). However, there can exist some customers that are not satisfied by their reliability determined by adopting the SORP and they may be eager to have a higher level of reliability. Therefore, other planning in addition of SORP is required to concern the customer viewpoint reliability. This paper introduces the customer-oriented reliability planning (CORP) in medium voltage network which is an innovative approach in the context of load point reliability. To this end, first a SORP is conducted to improve the distribution system reliability index. Then the strategy is revised and the CORP is adopted by DisCo considering involving the results obtained in SORP and the customers that have declared to reduce their expected energy not supplied (EENS). Since the surplus investment cost stem from the planning revision is received from the requestor customers, CORP can provide a proper and acceptable mechanism to fairly allocate the surplus cost to those customers. Furthermore, this problem is studied under the probabilistic nature of distribution network. Simultaneous placement of distributed generators (DGs) and automatic sectionalizing switches is implemented too with a new defined load shedding mechanism in order to enhance the reliability level for both mentioned planning frameworks.
M. Khodsuz
Abstract
In this paper, a novel approach for detecting islanding events in distribution networks special for synchronous generator type is presented. The proposed method leverages information derived from negative sequence voltage components, synchronous generator field voltage, positive sequence impedance variation ...
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In this paper, a novel approach for detecting islanding events in distribution networks special for synchronous generator type is presented. The proposed method leverages information derived from negative sequence voltage components, synchronous generator field voltage, positive sequence impedance variation rate, voltage harmonic distortion factor, and features extracted through wavelet transform applied to voltage waveforms. In order to establish a robust classification system without the necessity of explicit threshold determination, a pattern recognition method is employed. The dataset derived from these characteristics undergoes training using multi-layer support vector machines and a random forest optimization algorithm, resulting in five distinct classes. The study incorporates experimental samples encompassing various scenarios such as symmetric and asymmetric fault occurrences, load variations at different points, capacitor bank switching, variable load switching, nonlinear load switching, and islanding on a modified 34-bus IEEE network. The proposed islanding detection method demonstrates its effectiveness in distinguishing electrical islanding from power quality phenomena such as voltage oscillation, voltage sag, voltage swell, and dynamic voltage changes. Conducted simulations in MATLAB validate the efficacy of the proposed method.
Distribution Systems
O. Eghbali; R. Kazemzadeh; K. Amiri
Abstract
State estimation in the energy management center of active distribution networks has attracted many attentions. Considering an increase in complexity and real-time management of active distribution networks and knowing the network information at each time instant are necessary. This article presents ...
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State estimation in the energy management center of active distribution networks has attracted many attentions. Considering an increase in complexity and real-time management of active distribution networks and knowing the network information at each time instant are necessary. This article presents a two-step multi-area state estimation method in balanced active distribution networks. The proposed method is based on the location of PMU measurements of the network. The network is divided into several sub-areas about PMUs in the first step. A local sate estimation is implemented in each sub-area. The estimated values of the first step along with real measurements are used as measurements for second step estimation. The measurements are located in each sub-area using these values based on the ellipse area method, and the best location of measurements is extracted. Therefore, a second step state estimation including integrated state estimation of the whole network is performed by using the measurements obtained and located from the first step. The estimation results of the first step are used in the second step which improve the estimation accuracy. Simulations are performed on a standard IEEE 69-bus network to validate the proposed method.
Electric Mechinces & Drive
M. Megrini; A. Gaga; Y. Mehdaoui
Abstract
Utilizing electric vehicles (EVs) in place of conventional vehicles is now necessary to lower carbon dioxide emissions, provide clean energy, and lessen environmental pollution. Numerous researchers are trying to figure out how to make these electric vehicles better in order to address this. Electric ...
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Utilizing electric vehicles (EVs) in place of conventional vehicles is now necessary to lower carbon dioxide emissions, provide clean energy, and lessen environmental pollution. Numerous researchers are trying to figure out how to make these electric vehicles better in order to address this. Electric motors and batteries are necessary parts of electric cars. As such, the development of these vehicles was associated with the development of these two entities. This review lists all of the sophisticated electric machines, their control schemes, and the embedded systems that are utilized to put these schemes into practice. Due to this review, we determined out, the induction motor and permanent magnet synchronous motor have been demonstrated to be the most efficient and suitable alternative for propulsion drive in electric vehicles. Furthermore, because torque and speed can be controlled simultaneously with minimal noise and ripples, the FOC approach continues to be the ideal control method. This evaluation offers comprehensive information regarding the application of various control measures. Whereas the model- based design technique made it easier for engineers to program, validate, and fine-tune the system’s controllers before deploying it in the field, STM32 and DSP320F28379 are the best embedded systems for implementation because of their low cost and compatibility with the SIMULINK environment.
Power System Stability
F. Babaei; A. Safari
Abstract
The EVs battery has the ability to enhance the balance between the load demand and power generation units. The EV aggregators to manage the random behaviour of EV owners and increasing EVs participation in the ancillary services market are employed. The presence of aggregators could lead to time-varying ...
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The EVs battery has the ability to enhance the balance between the load demand and power generation units. The EV aggregators to manage the random behaviour of EV owners and increasing EVs participation in the ancillary services market are employed. The presence of aggregators could lead to time-varying delay in load frequency control (LFC) schemes. The effects of these delays must be considered in the LFC controller design. Due to the dependency of controller effectiveness on its parameters, these parameters should be designed in such a way that the LFC system has desired performance in the presence of time-varying delay. Therefore, a Sine Cosine Algorithm (SCA) is utilized to adjust the fractional-order PID (FOPID) controller coefficients. Also, some evaluations are performed about the proposed LFC performance by integral absolute error (IAE) indicator. Simulations are carried out in both single and two area LFC system containing EV aggregators with time-varying delay. According to results, the proposed controller has fewer frequency variations in contrast to other controllers presented in the case studies. The obtained output could be considered as a solution to evaluate the proposed controller performance for damping the frequency oscillations in the delayed LFC system.
Power System Control
V.K. Peddiny; B. Datta; A. Banerjee
Abstract
Changes in the electric supply can significantly affect electronic devices since they are very sensitive. Due to a nonlinear system with multiple interconnected and unpredictable demands in the smart grid, the electricity system is facing several issues, including power quality, reactive power management, ...
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Changes in the electric supply can significantly affect electronic devices since they are very sensitive. Due to a nonlinear system with multiple interconnected and unpredictable demands in the smart grid, the electricity system is facing several issues, including power quality, reactive power management, and voltage drop. To address these problems, a static synchronous compensator (STATCOM) is frequently used to compensate and correct the voltage level at the power bus voltage. In this study, an Artificial Neural Network (ANN) and GWO based controlled STATCOM has been developed to replace the traditional PI based controller and enhance the overall STATCOM performance. The ANN controller is preferred due to its simplicity, adaptability, resilience, and ability to consider the non-linearities of the power grid. To train the classifier offline, data from the PI controller was utilized. The MATLAB/Simulink software was employed to assess the effectiveness of STATCOM on a 25 Km transmission line during increased load and three faults. The combined results of the PI and ANN controllers indicate that the ANN controller significantly improves STATCOM efficiency under different operating conditions. Moreover, the ANN controller outperforms the traditional PI controller in terms of results.
Planing & Reliability
A. Bagheri; A Rabiee; S. Galavani; F. Fallahi
Abstract
Flexible AC Transmission Systems (FACTS) devices have shown satisfactory performance in alleviating the problems of electrical transmission systems. Optimal FACTS allocation problem, which includes finding optimal type and location of these devices, have been widely studied by researchers for improving ...
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Flexible AC Transmission Systems (FACTS) devices have shown satisfactory performance in alleviating the problems of electrical transmission systems. Optimal FACTS allocation problem, which includes finding optimal type and location of these devices, have been widely studied by researchers for improving variety of power system technical parameters. In this paper, a DIgSILENT-based Discrete Particle Swarm Optimization (DPSO) algorithm is employed to manage the power flow, alleviate the congestion, and improve the voltage profile in a real case study. The DPSO have been programmed in DPL environment of DIgSILENT software and applied to the power grid of Gilan Regional Electric Company (GilREC), located in north of Iran. The conducted approach is a user-friendly decision making tool for the engineers of power networks as it is executed in DIgSILENT software which is widely used in electric companies for the power system studies. The simulation results demonstrate the effectiveness of the presented method in improving technical parameters of the test system through several case studies.
Electric Mechinces & Drive
D.M. Sonje; R. Munje
Abstract
Fault detection and classification (FDC) is a vital area in the health monitoring of three-phase induction machines. According to the failure survey of three three-phase induction machines, bearing-related faults cause a percentage of motor failures in the range of almost 41-50% which is very significant. ...
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Fault detection and classification (FDC) is a vital area in the health monitoring of three-phase induction machines. According to the failure survey of three three-phase induction machines, bearing-related faults cause a percentage of motor failures in the range of almost 41-50% which is very significant. These faults may occur one or multiple at a time in the bearing. With a well-designed fault detection method, failure of the motor can be reduced and productivity can also be increased. This paper proposes the simultaneous bearing fault detection and classification in three three-phase induction machine using the combination of feature fusion method and intelligent random forest (RF) algorithm. The paper contributes in two folds. In the first part of the paper, the performance of traditional methods such as vibration and current analysis is tested in which statistical parameters obtained from current and vibration signals are passed separately to the intelligent random forest classifier. In the second part of the paper, statistical parameters obtained from current and vibration signals are fused together and used as inputs to the RF classifier. The accuracy and various other performance measures are calculated and based on experimental results; a remarkably high detection/classification performance is achieved.
Power Electronic
M. R. Banaei; H. Ajdar Faeghi Bonab; N. Taghizadegan Kalantari
Abstract
In this paper, a new transformerless buck-boost converter based on ZETA converter is introduced. The proposed converter has the ZETA converter advantages such as, buck-boost capability and input to output DC insulation. The suggested converter voltage gain is higher than the classic ZETA converter. In ...
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In this paper, a new transformerless buck-boost converter based on ZETA converter is introduced. The proposed converter has the ZETA converter advantages such as, buck-boost capability and input to output DC insulation. The suggested converter voltage gain is higher than the classic ZETA converter. In the presented converter, only one main switch is utilized. The proposed converter offers low voltage stress of the switch; therefore, the low on-state resistance of the main switch can be selected to decrease losses of the switch. The presented converter topology is simple; hence, the control of the converter is simple. The mathematical analyses of the proposed converter are given. The experimental results confirm the correctness of the analysis.
Electric Mechinces & Drive
H. Zaimen; A. Rezig; S. Touati
Abstract
Voltage source inverters (VSIs) based on insulated-gate bipolar transistors (IGBTs) may face various faults that can affect the operation and safety of the entire electric drive system. To enhance the reliability of the drive system, it is crucial to develop an accurate fault diagnosis (FD) method and ...
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Voltage source inverters (VSIs) based on insulated-gate bipolar transistors (IGBTs) may face various faults that can affect the operation and safety of the entire electric drive system. To enhance the reliability of the drive system, it is crucial to develop an accurate fault diagnosis (FD) method and increase fault tolerance control (FTC) capabilities. This paper provides a novel FTC strategy for IGBT open circuit fault (OCF) in induction motor (IM) drives. The proposed FTC strategy includes a fault diagnosis algorithm and inverter reconfiguration. A three-phase current-based diagnosis method (FD) is adopted in this research, where the average absolute value of the normalized currents is used to extract fault detection variables. The developed FD method does not need any extra sensors and provides fast diagnosis time, which is equivalent to almost 25-30% of the phase current’s fundamental cycle. To accomplish satisfactory post-fault operation of the IM drive, a four-leg inverter topology is employed. Finally, the effectiveness of the proposed fault-tolerant drive and diagnosis method is proven through various simulation results.
