International Journal of Applied Power Engineering (IJAPE)
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A-star algorithm based on admissible searching for strategically placing PMU considering redundancy and cost/benefit analysis
Get PDFThis research examines an admissible search algorithm-dependent A-star strategy and takes into account redundancy and cost/benefit analysis under normal operating conditions. The goal is to allocate a phasor measurement unit (PMU) for maximal observability of the interconnected power network. To determine the fewest number of PMU required to make the connected power network totally observable using redundancy analysis, the A-star approach is utilized. The redundancy analysis of the power network is carried out in order to determine the appropriate PMU placement, which results in the acquisition of total power network observability and reliability. To put the suggested technique through its paces, it has been tested on IEEE-standard test systems such as IEEE-14 bus, IEEE-30 bus, New England-39 bus, IEEE-57 bus, and IEEE-118 bus. The results obtained using the suggested methodology are compared to those obtained through standard literature research. The experimental findings of the suggested method revealed the resilience and accuracy of the A-star algorithm as well as its effectiveness in achieving maximum observability of the connected power network
Power loss minimization assessment of a doubly fed induction generator with variable core resistance for wind turbines operation
Get PDFThis paper assesses the efficiency level and power loss minimization of a doubly fed induction generator (DFIG). A modified DFIG equivalent circuit with multi-core resistance connected in parallel was adopted. State-space differential equations of the DFIG was developed incorporating iron and copper loss components while a minimum flux linkage that aids in the minimization of the overall losses was derived. Simulation results showed that losses were minimized when the equivalent core resistances were connected in parallel with minimum permissible current flow. The results obtained during a transient disturbance showed that at different core resistance values of Rfe = 0.75Ω and 0.25Ω, different efficiency values of 83.45% and 41.21% were realized. An unconstrained optimization test carried out on the DFIG variable parameters showed that the DFIG power loss model was controllable with a positive definite value of 691.9801 and 2.9156〖e〗^(+5) for the leading principal determinants of the Hessian matrix. All simulation processes were achieved in MATLAB/Simulink 2020
Inverter based implementation of maximum power point techniques
Get PDFThe utilization of renewable energy sources is being pushed by both greater environmental consciousness and expanding demand. Recently, solar photovoltaic technology has found increased use for a broader range of applications. This may be ascribed to solar energy's extensive availability as well as its long-term viability and low cost. According to the global photovoltaic (PV) industry, 594 gigawatts (GW) of PV capacity were installed in 2019, with the objective of replacing conventional source-based generating facilities. The major problem in PV production, however, is identifying the maximum power point tracking (MPPT) systems that are currently in use to compute peak output. For 1240 W PV power plants, this article compares perturb & observe MPPT approaches with incremental conductance MPPT techniques. The MATLAB Simulink program was utilized to conduct the study, which was based on many factors such as voltage, current, and output power under various weather conditions. When these MPPT algorithms are applied to solar trackers, the efficiency, reaction time, and steady-state oscillations all improve
Analysis of switched impedance source/quasi-impedance source DC-DC converters for photovoltaic system
Get PDFThis paper proposes the switched impedance source converter (SZSC) or switched quasi impedance source DC-DC converter (S-qZSC) based photovoltaic (PV) grid-connected systems. To increase the voltage from low level to high level, all PV grid-connected systems need step-up DC-DC converters. This step-up factor can be increased by connecting the terminals of a traditional quasi impedance source DC-DC converter with an additional diode and a switch. In this proposed converter, the capacitor not only serves as a filter. It is, however, bound in series to the charging loops of the inductors. On the one hand, saturated inductors can trigger instability, which can be avoided. When used for dc-ac conversion, however, the modulation index of the backend H-bridge can be set to a wider range. As compared to existing Z-source-based systems, a shorter duty period results in a higher boost factor
DFT calculations of the main optical constants of the Cu2ZnSnSexS4-x system as high-efficiency potential candidates for solar cells
Get PDFIn the present work, using quantum-chemical calculations in the framework of density functional theory (DFT), we study the optical properties of semiconductor nanocrystals of kesterite Cu2ZnSnS4 doped with Se. Using the WIEN2k package, the concentration dependences of the optical characteristics of nanocrystals of the Cu2ZnSnSexS4-x system (x = 0, 1, 2, 3, 4) were calculated. It is shown that doping with Se at the S position leads to a noticeable improvement in the photo absorbing properties of these nanocrystals, as well as their photoconductivity in the IR range. The calculated absorption and extinction spectra of the materials under study, are compared with experimental data known from the literature. The data obtained will significantly enrich the existing knowledge about the materials under study and will help expand the scope of these compounds in optoelectronic devices, especially in solar cells and other devices that convert solar energy into electricity
Economic dispatch of an islanded microgrid
Get PDFMicrogrids are increasingly becoming popular to improve energy access and increase the resiliency of weakly connected rural networks. The economic operation of these microgrids with renewable energy resources is key for maximizing the benefits. The objective of this paper is to implement the economic dispatch of a microgrid using quadratic programming, considering the active and reactive power capability of the renewable energy resources. The open distribution system simulator (OpenDSS) is used for obtaining the load flow of the distribution network, and the converged solution is given as input to MATLAB for optimization. The simulation is carried out for one day with a variation of hourly load, solar PV radiation, and wind in both grid-connected and islanded modes under six different cases. The methodology is implemented on a modified IEEE-13 node test feeder distribution system. The simulation result shows that the microgrid with distributed generation (DG) capable of supplying both active and reactive power under islanded conditions is economical when compared to the grid-connected mode. The novelty of the work is that it considers the capability of distributed generation to supply both active and reactive power. That can make it fully autonomous as it can meet the hourly load requirement of the network under islanding mode as per IEEE Standard 1547.4
Artificial intelligence for energy fraud detection: a review
Get PDFEnergy fraud in the distribution sector of electric utility includes electricity theft, meter tampering, or billing error. This fraud causing non-technical loss has led to an economic loss of the company. In order to detect and minimize fraud, different technologies have been used. From conventional methods to development in the field of artificial intelligence (AI), effective and reliable fraud detection methods have been proposed. This paper first provides an overview of different proposed methods for non-technical loss detection and evaluate the advantage and limitation of using those methods. Furthermore, several supervised and unsupervised machine learning methods for detecting electricity theft are discussed in summary along with their metrics and attributes used. Finally, these methods are classified based on the overall operation and the parameters used. This paper provides comparisons of several fraud detection methods using AI along with their weak and strong points and this information is very useful for the researchers who are working in the field of AI method for detecting fraud
Design and development of photovoltaic based grid interactive inverter
Get PDFIn order to trail and produce the power generated on the photovoltaic (PV) array to the grid, a PV exhibit coordinated double lift DC-AC converter used as a contained single-stage micro inverter is introduced in this research. The flowing association of a DC converter, rectifier, and an inverter is used in the single-stage micro inverter to provide high supporting rise with a minimal obligation proportion. Due to the utilization of a greater variety of force-exchanging devices, the flowing association of the converters, however, gives limited change efficacy. With fewer switches and hidden components, the suggested disengaged double lift small inverter is intended to provide high power from maximum power point tracking (MPPT) proficiency, high transformation proportion, and high change effectiveness. The stoop reflections and the small inverter's six distinct techniques are presented. To support the display of the double lift DC-AC converter worked small inverter, the recreation and results of the exploratory proto sort are presented
A comparative braking scheme in auto-electric drive systems with permanent magnet synchronous machine
Get PDFPermanent magnet synchronous machines (PMSMs) are gaining popularity due to renewable energy and the electrification of transportation. Permanent magnet synchronous machines are receiving interest because to their great dependability, low maintenance costs, and high-power density. This research compares surface mounted permanent magnet (SMPM) with interior permanent magnet (IPM) synchronous machines using MATLAB. Mathematical models and simulation analyses of two permanent magnet synchronous machines under regenerative braking are presented. Maximum regeneration power point (MRPP) and torque (MRPP-torque) for two machine types were simulated at variable electrical speed and q-axis current. Simulation results showed IPMSM produced more output power due to saliency than SMPM at varying speed and current with higher MRPP and MRPP-Torque. Simulation was used to compare the dynamic impacts of constant and variable braking torques on an auto-electric drive's speed and produced torque on a plain surface and a sloppy driving plane. 81.68% and 74.95% braking efficiency were measured on level ground and a sloppy plane, respectively. Simulations indicated that lithium-ion battery state of charge varied linearly with constant braking torque and exponentially with varying braking torque, reflecting efficiency values. All simulations were in MATLAB/Simulink 2014
PI-based PLL and 24-sector control of a 3P-3L-NPC inverter for grid-tied PV system synchronization
Get PDFThis article addresses one of the most serious issues in electricity: frequency and voltage anomalies. Actually, because renewable energy production is intermittent, the frequency and voltage of electricity produced are unstable and dependent on weather conditions. This issue causes industrial processes to fail, affecting the quality of the electrical supply and having a massive economic impact. Power electronics inverters are designed to compensate for system fluctuations in solar power generation. However, measurement noise in the grid voltage desynchronizes the inverter and network signals. The authors propose using a phase-locked loop technique based on inverter period control and a network voltage observer to achieve such synchronization of grid-connected photovoltaic (PV) systems. In this work, the grid integration of the PV system is carried out through a three-phase three-level neutral point clamped inverter due to better current quality with fewer harmonics and lower stress voltage of the inverter's components when compared to two-level voltage source inverters. The method is successfully applied in a simulated case study and experimental results validate it