Calculation Of Reactive Power Research Articles

Distributed sliding mode control for reactive power sharing in an islanded microgrid

This paper presents a novel microgrid secondary control method based on distributed sliding mode control, addressing the issue of reactive power sharing in islanded microgrids. Acknowledging the complications posed by feeder impedance mismatch, the traditional droop control mechanism fails to facilitate efficient reactive power sharing. Utilizing a distributed framework, this paper initially introduces a reactive power ratio observer, enabling the observation of global average reactive power without the need for precise reactive power calculation as required in a conventional centralized control setup. Subsequently, employing the devised reactive power ratio observer, sliding mode control is integrated to achieve effective reactive power sharing. Furthermore, this paper broadens its scope to encompass both reactive power sharing and voltage restoration, resulting in the design of a comprehensive controller. Notably, the proposed distributed sliding mode controller not only achieves accurate reactive power sharing but also exhibits significant resilience in the face of load disturbances. The simulation results conducted under various scenarios effectively validate the efficacy of the proposed distributed sliding mode control strategy.

Penempatan Kapasitor Paralel pada Penyulang Pajajaran GI Jakabaring

In order to compensate for reactive power on electrical power distribution lines, parallel capacitors have been utilized extensively. Capacitor placement does not constantly improve the total voltage and power factor. Therefore, it is crucial to establish the ideal capacitance (size) and position of the capacitors to reduce power losses in the distribution line. Palembang City's New Jakabaring Substation is a substation situated in a region with a rapid load increase. Pajajaran Feeder, one of the several feeders at this substation, carries the weight of numerous significant loads as well as expanding residential areas. Reactive power computation and optimal capacitor placement (OCP) were the two simulation techniques used in the study, which were carried out using ETAP 19.0. The study's findings demonstrate that using reactive power calculations, the original Padjajaran feeder voltage drop is improved from 93.26% to 98.98% while utilizing OCP, the voltage drop is improved from 93.26% to 100.1%. However, OCP provides a more consistent capacitance value of the capacitors in the range of 930 kVAR compared to reactive power calculations, whose results are more inconsistent. Calculations using OCP gives more capacitors, namely as many as 20 more than those produced by calculating the reactive power of 14 capacitors. The location of parallel capacitors in the Padjajaran feeder can function optimally and support a load of up to 80% of the transformer capacity rating.

Parallel inverter control using different conventional control methods and an improved virtual oscillator control method in a standalone microgrid

Partly because of advances in power electronic converters, the share of renewable energy in power generation is steadily increasing. The main medium of interface for integrating renewable energy sources to the utility grid is the power electronic inverter. Virtual oscillator control (VOC) is a time-domain approach for controlling parallel inverters in a standalone microgrid (MG). The concept is to simulate nonlinear deadzone oscillator dynamics in a system of inverters to ensure a stable AC MG in the absence of communication. VOC is a time-domain and self-synchronizing controller that simply requires the measurement of filter current, whereas traditional droop control and the virtual synchronous machine (VSM) require low pass filters for active and reactive power calculations. In this work, a particle swarm optimization (PSO)-based VOC method (VOC-PSO) is proposed, in which the parameters of the VOC are designed using the PSO algorithm. The system performance using droop, VSM, VOC, and VOC-PSO controllers are investigated using MATLAB and Opal-RT real-time digital simulator platforms. The results show that the proposed VOC-PSO gives improved performance over other control strategies. The efficacy of the proposed VOC-PSO control method is also demonstrated by the experimental results.

New Adaptive Broadband Full-Bridge Converter Impedance Matching Network for Giant Magnetostrictive Transducer

This article proposes an adaptive broadband full-bridge converter impedance matching network (FCIMN) between a power amplifier and the giant magnetostrictive transducer (GMT). Compared with the conventional passive impedance matching methods, the proposed one can realize the load impedance matching of power amplifiers under a wide frequency range. In this article, first, the elementary principle of operation of FCIMN is introduced mathematically. After that, a control method is proposed to achieve adaptive broadband impedance matching, including dynamic active power calculation, reactive power calculation, segmented proportional–resonant controller and combined feedback and feedforward voltage control. On this basis, the parameter design method is proposed for the operating frequency range. Finally, the simulation and laboratory-scale experimental results are provided to validate the effectiveness of the proposed FCIMN, discussions, and control method. It clearly shows that the proposed FCIMN can adaptively match load impedance for the different GMTs, broadband range, and the power amplifier power utilization factor is significantly improved.

Electric Arc Furnaces Reactive Power Optimized Calculation Used in SVC

This study deals with a new approach to tackle the challenges encountered in the filters-based reactive power calculation techniques utilized in the control system of static VAr compensators. In this approach, step and time-varying responses are improved by a combination of differential and filter-based methods. Then, optimum values of the main parameters of the low-pass and band-stop filters are determined considering three criteria: accuracy, speed, and capability for following the time-varying loads. To assess the performance of the proposed method, a new objective function is introduced, calculated for two sets of signals, captured from a real field in Mobarakeh Steel Company in Isfahan/Iran. Then, the proposed and the other reactive power calculation methods are assessed in practice and simulation. Also, the algorithm is implemented using a TMDSCNCD28335 as the processor to assess the real-time feasibility of the method. To do so, the reactive power variation of an electrical arc furnace is emulated in a prototype test bench and the algorithm is run in real-time by the processor during the system operation.

Pengaruh Tegangan Eksitasi Terhadap output Tegangan Generator Sinkron 3 Fasa 6,3kV

Synchronous generators work by changing mechanical energy into 1 and 3 phase electrical energy. Reactive power is needed by consumers to generate magnetic fields in inductive electrical loads. The reactive power setting can be adjusted by increasing or decreasing the excitation current. Excitation current is a DC electric current that is supplied to the generator rotor to generate a magnetic field. The excitation current is proportional to the reactive power released by the generator. This is indicated by the increase in the reactive power of the generator which was initially valued at 0.6999 MVAR to 0.7655VAR after the excitation current was increased from 0.130 kA to 0.140 kA. The data used is measurement data per day from July 1 to July 14, 2022. Calculation of reactive power using the power triangle formula has results that are close to the values of reactive power measured by the largest difference of 0.0198 MVAR or 2.8637547%. The reactive power is all positive so the state of the generator is lagging. The output voltage tends to be stable near the nominal voltage of 6.3 kV, this is because the increase and decrease in excitation is intended to keep the generator output voltage stable.

Comparison and analysis of several instantaneous reactive power calculation methods

Briefly describes several more common algorithm of reactive power when the input signal is a sine signal and research all kinds of reactive power calculation method, through matlab using the theory of monte carlo random multiple sets of random number them as the amplitude and phase Angle of voltage, current, the different calculation method of the size of the instantaneous reactive power, To get the best calculation method. Multiple groups of random numbers can avoid the error caused by using only one set of data for testing in existing papers.

Prediction of wind farm reactive power fast variations by adaptive one-dimensional convolutional neural network

One of the prominent problems in wind farms is voltage flicker emission. To prevent flicker emission or mitigate the impact as best as possible, a static VAr compensator (SVC) is a great candidate both economically and technically. However, SVCs cannot completely compensate the fast-changing reactive power due to delays caused by the reactive power calculation unit and the triggering fire angle of the SVC. This paper proposes a predictive control system for SVCs, by merging an additional predictive control block into the conventional control system. It is constructed based on deep neural networks, namely adaptive one-dimensional convolutional neural network (1D-CNN). The training process is conducted based on the adaptive learning weights process to enhance the prediction accuracy and training computational complexity of the 1D-CNN. Numerical results on the actual dataset in a wind farm in Manjil, Iran, have verified the forecasting accuracy and flicker mitigation of the proposed controller.

Reactive Power of Asynchronous Electric Drives with Semiconductor Converters

The purpose of the article is to obtain a ratio for determining the reactive power of induction motors when powered by semiconductor converters. The task is to determine the dependence of reactive power on control parameters of the converters. The research method used is computer simulation of electric drive based on Fryze power theory for non-sinusoidal currents. The result is the obtained expression for the calculation of reactive power, which takes into account the rated idle current of the motor with sinusoidal power supply and the type of converter, due to introducing special coefficients. Numerical values of the latter, depending on the control parameter, are obtained on computer models with their subsequent approximation. The scientific novelty of the research is in the further development of Fryze power theory in the direction of decomposition of non-sinusoidal current components using computer models. The practical significance is the obtained expression for determining the reactive power of an asynchronous electric drive with a thyristor voltage converter, on the basis of which the capacity of compensating capacitors is calculated to increase its energy efficiency.

Filters Optimized Tuning for Wind Farms Reactive Power Calculation

Fast reactive power variation in wind farms creates flicker. Static VAR compensators (SVCs) are the most commonly used devices for flicker mitigation. The reactive power calculation unit is the main component in the control system of SVCs. This article deals with two new approaches for reactive power calculation. In both methods, the main parameters of a filter-based technique are optimized using a novel optimization approach. The first method has a non monotonic step response which is converted to a desirable monotonic response by the second method. This results in a better response to a time-varying reactive power. The problem formulation and definition of a new objective function are presented. A data pool is gathered from Manjil wind farm, Iran, for different conditions. This data pool is used in the objective function to derive the optimal setting. The performance of the proposed methods is assessed using this dataset and is compared with other techniques. Also, real-time implementation of the algorithm is evaluated using TMDSCNCD28335 as the processor. To do so, the reactive power variation in a wind generation unit is emulated in a prototype test bench and the algorithm is run in real-time by the processor during the system operation.

Response Time of Reactive Power Based on Different Definitions and Algorithms

Dynamic reactive power compensation equipment typically requires a fast response to output the necessary reactive power. The term “dynamic response time of reactive power” is often used but has never been clearly defined. This paper summarizes the reactive power calculations under different definitions and algorithms and considers these calculations in terms of signal processing to simulate and analyze the step response. This paper subsequently focuses on the widely used instantaneous reactive power algorithm and finally concludes that the dynamic reactive power response time closely depends on the reactive power calculation method itself. The single-phase instantaneous reactive power algorithm has the fastest response time. The reactive power response time of dynamic reactive devices in power systems is a minimum of a quarter of one cycle time for the well-known and widely used single-phase reactive power algorithms.

Effect of higher harmonics on electric power metering in a steel maker’s power networks

This paper describes the results of a study that looked at how harmonic voltage and current distortions affect the power metering equipment of an aluminium plant. Aluminium industry power supply circuits and power consumers have been analyzed. The main requirements are specified with regard to power monitoring systems designed for major consumers. It is shown that when calibrating commercial-type digital power meters no testing is required for the conditions of voltage or current distortions. At the same time, it is in these conditions that such devices are utilized at feeder points with non-linear loads. As a result of a series of laboratory studies, it was found that the number of the considered harmonics, their amplitude and the phase displacement angle at 50 Hz produce most effect on the active and reactive power monitoring error. The authors also analyzed mathematical models of the power and electric power meters in relation to the active and reactive power calculated in the presence of higher harmonics. It is shown that different mathematical equations can be used to calculate the reactive power using the current metering devices. The paper presents some measurement data on the electric power quality and the power consumption parameters from the compressor stations and the process water plants of an aluminium plant. The data show that the total voltage harmonics go beyond the allowable limit, and the distortions in that point are caused by variable frequency converters of the electrolysis facility. The measured parameters were used as the basis for estimating the error of the electric power meters for various mathematical models implemented in the meters. It was found that the discrepancy between the first harmonic method and the geometry method in the reactive power calculation can reach 6%.This research was funded by the Russian Science Foundation, Project No. 18-79-00127.

Sensorless Virtual Flux Combined Control of Grid Connected Converters With High Power Quality Under Unbalanced Grid Operation

This paper presents a novel sensorless combined control for grid connected power electronic converters (GCCs) under both balanced and unbalanced grid operation. Under unbalanced grid conditions, output power quality of GCCs would usually be deteriorated by increased current harmonics and power oscillations injected to grids. To overcome the problem, an improved sensorless combined control method with a new switching logic is presented in this paper based on instantaneous control of grid current components. The simplicity and robustness of combined control is fully preserved due to a current reference vector, which is calculated using the virtual flux components in the grid voltage, and virtual flux reference frames without any positive and negative sequence extraction. The proposed method, in comparison with voltage oriented control, avoids problems of tuning current controller, PWM sub-system, and decoupling circuit. Compared to the direct power control, the method lacks active and reactive power calculation and voltage sensors and enjoys improved power ripples and current THD.

Comparative of Power Calculation Methods for Single-Phase Systems under Sinusoidal and Non-Sinusoidal Operation

This article presents a comparative experimental evaluation of some power calculation methods used for three-phase and single-phase systems. In order to make the comparison, methods based on three reference frames, the natural one, αβ and dq, are considered. This paper addresses the experimental comparison for single-phase systems facing sinusoidal and non-sinusoidal waveforms in both linear and non-linear loads. The results are obtained from an experimental platform consisting of a controlled voltage inverter and an acquisition system based on a TMS320F28335, where the power calculation algorithms are implemented. The experimental comparison of the different methods for active and reactive power calculation is made in terms of accuracy and processing time in digital implementation.

Fuzzy MRAS rotor resistance identification of BL-IM based on reactive power

As for the inverse decoupling control system of a bearingless induction motor (BL-IM), in order to eliminate the influence of rotor resistance variation on its control performance, on the basis of the reactive power calculation of torque system, a novel fuzzy model reference adaptive (MRAS) identification method of rotor resistance is proposed. The reference model and adjustable model of instantaneous reactive power are derived in detail. In order to improve the identification performance of rotor resistance, a fuzzy PI adaptive law based on popov super stability theory is constructed. On this basis, a rotor resistance identifier is constructed, and it is used to on-line correct the rotor resistance parameter in the inverse system mathematical model of a BL-IM system. Based on the inverse decoupling control system of a BL-IM, the simulation experimental analysis and verification are carried out. The simulation experimental results have shown that when the proposed identification method of rotor resistance is used, not only the identification- and tracking-speed of rotor resistance can be effectively improved, but also the identification accuracy of rotor resistance can be improved; as for the BL-IM system, after the rotor resistance parameter is on-line corrected, not only the inverse dynamic decoupling control performance can be effectively improved, but also the robustness of BL-IM system to the variation of rotor resistance parameters can be improved.

Development of the algorithm of calculation of reactive power by harmonic components

Development of the algorithm of calculation of reactive power by harmonic components

Development of the algorithm of calculation of reactive power by harmonic components

The article presents the development of the algorithm for the study of higher harmonics of current and voltage. Research includes the harmonic interaction between transducers and power systems, as well as the simulation of higher harmonics research. The information on the application of the algorithm on the modern tool base is given.

Tracking technique for the sudden change of PV inverter load

Many power electronics applications require a power calculation in the control system. To get a suitable output, engineers need to control the process and regulate the power exchange with the grid. Since real and reactive power calculations are so crucial a topic, a novel control strategy for a single-phase photovoltaic (PV) inverter has been developed. Therefore, Direct power control (DPC) and a single-phase three-level space vector pulse width modulation (SVPWM) combine as a control and modulation system. In this paper, predictive real and reactive power control and SVPWM method are conferred in the inner loop. A voltage controller based on a proportionalintegral (PI) scheme is used in the outer loop to acquire constant output voltage and provide power refers to the DPC. The performance of the proposed method is verified by using MATLAB/SIMULINK.

Design of multi-functional intelligent power monitoring instrument

the real-time detection record of power quality can accurately and quickly analyze the factors that affect the power quality, which is of great significance to improve the national power quality. At present, the electric power monitoring instrument in the market can basically realize the measurement of electric power parameters, but the function is single and the practicability is not strong. So we designed a multi-functional intelligent power monitoring instrument, with three-phase voltage and current detection, harmonic detection, active power and reactive power calculation, electricity calculation, frequency measurement, vector graph, and other functions. The hardware and software design methods of the instrument are described. The window-interpolation FFT algorithm is used to calculate the power parameters, and the sampling frequency can be adjusted in time to reduce the influence of the barrier effect on the system. The test shows that the electric power meter is accurate, small in size, complete in function, simple in operation, and has serial communication function, which is worth popularizing.

Impact of Renewable Energy Sources as Co-generation Plant on Power System Network

This paper focuses on the power system evaluation due to integration of renewable energy sources like bagasse and biogas. The coal is only used when bagasse is not available. Two factor is taken for evaluation purpose like on season and off season scenario. The main objective of the work to supply surplus electricity to the national grid after fulfilling its own consumption. In this research a 6.3MW co-generation plant has been performed in Power Factory software for analyses. Simulation result shows load flow calculation, voltage deviation, total loss, external feed, active power and impact of reactive power, and required MVAR at two operation scenarios. The final result looks quite encouraging and this proposed co-generation system can be the framework to be developed for ameliorating energy crisis in Bangladesh.