فهرست مطالب

Journal of Operation and Automation in Power Engineering
Volume:13 Issue: 3, Autumn 2025
- تاریخ انتشار: 1404/05/10
- تعداد عناوین: 8
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Pages 184-195Distribution 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.Keywords: Distribution System State Estimation (DSSE), Weighted Least Squares (WLS), Meter Placement, Nonlinear Optimization Mesh Adaptive Direct Search (NOMADS)
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Pages 196-205Nowadays, with the detrimental impacts of air pollution on human health and its significant societal expenses, it has been imperative to utilize renewable energy sources (RESs) and energy storage systems (ESSs). This study introduces a new objective function aimed at achieving a long-term optimal plan where it contrasts the outcomes of meeting network load demand with and without the integration of renewable/non-renewable distributed energy resources (DERs). The analysis considers installation and operational costs, addressing uncertainties through Monte-Carlo and scenario-based methodologies. The proposed problem is structured as a convex optimization model. Simulations are conducted on the IEEE 33-bus system, showcasing the model’s efficacy through cost efficiency and reduced emission expenses. The study confirms that the investment in renewable energy resources and ESS units can be recouped in less than five years. It was observed that in the long-term, there is a cost reduction of 29.4\% when DER units are incorporated. Also, the emission cost for the horizon year is diminished by 43.2\% compared to the case where the DERs are absent.Keywords: Distribution System Planning, Renewable Energy Sources, Energy Storage Systems, Uncertainty, Convex Optimization
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Pages 206-211
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.
Keywords: Permanent Magnet Linear Motor, Cogging Force, Segmented Surfaced-Mounted Pmlsms -
Pages 212-222This 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.Keywords: Automatic Generation Control (AGC), Availability Based Tariff (ABT), Generation Control Error (GCE), Tie-Line, Frequency Linked Pricing
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Pages 223-230This 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.Keywords: Renewable Energy, Power Converter, High Voltage Gain, Reduced Ripple, Low Blocking Voltage
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Pages 231-237In 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.Keywords: Islanding Detection, Synchronous Generator, Support Vector Machines, Rendom Forest, Power Quality Phenomena
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Pages 238-247
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.
Keywords: Electric Machines, Embedded System, Model Based Design, Control Strategies -
Pages 248-254Changes 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.Keywords: STATCOM, ANN, Smart Grid, Grey Wolf