scholarly journals Current Harmonics Reduction In Microgrids Using Dual Interfacing Converters

2021 ◽  
Vol 12 (2) ◽  
pp. 1647-1654
Author(s):  
Venkatesh E , Et. al.
Keyword(s):  
Distributed Generation ◽  
Low Voltage ◽  
Supply Voltage ◽  
Control Technique ◽  
Test Results ◽  
Nonlinear Loads ◽  
Nonlinear Load ◽  
Current Harmonics ◽  
The Matrix ◽  
Over The Top

The Growing Installation of Distributed Generation (DG) units in low voltage conveyance frameworks has promoted the idea of nonlinear load symphonious current remuneration utilizing multi-utilitarian DG interfacing converters. In appropriation frameworks, the load has been an unexpected increment or diminishes and it resembles as nonlinear loads so the load draw non-sinusoidal flows from the AC mains and causes the load sounds and responsive power, and over the top impartial flows that give contamination in power frameworks. It is investigated in this paper that the pay of neighborhood load symphonious current utilizing a solitary DG interfacing converter may make the intensification of supply voltage sounds touchy loads, especially when the primary framework voltage is profoundly twisted. To address this impediment, in contrast to the activity of customary unified power quality conditioners (UPQC) with arrangement converter, another concurrent stock voltage and matrix current symphonious pay technique is proposed utilizing composed control of two shunt interfacing converters. Through the presentation of staggered control destinations, it is delineated that the proposed framework could ride through voltage unsettling influences and proceed with the power move between the nearby generation and the matrix, while an excellent voltage is kept up for the neighborhood loads. By utilizing this proposed regulator, the lattice voltage stage bolted circle and the identification of the load current and the stockpile voltage music are superfluous for both interfacing converters. In this manner, the computational load of interfacing converters can be fundamentally decreased. Mimicked and test results are caught to approve the exhibition of the proposed geography and the control technique.

scholarly journals Synchronized Control of Voltage and Current Harmonics in Distributed Generation System using Fuzzy Controller

2019 ◽  
Vol 8 (12) ◽  
pp. 1179-1182
Keyword(s):  
Distributed Generation ◽  
Energy Demand ◽  
Power Flow ◽  
Fuzzy Controller ◽  
Low Voltage ◽  
Load Condition ◽  
Control Technique ◽  
Current Harmonics ◽  
Simultaneous Control ◽  
Unbalanced Load

The worldwide energy demand is increasing due to increase in population and economic growth. The grid is gradually replaced by Distributed generation systems (DGs). Recently low voltage DG interfacing converter on the non linear load compensation is performed by unified power flow converter. The proposed control technique is analyzed for Simultaneous control of voltage and power under unbalanced load condition using MATLAB/SIMULINK software

scholarly journals Dependencies of current harmonics of some nonlinear load devices on rms supply voltage

2020 ◽  
Vol 33 (2) ◽  
pp. 261-271
Author(s):  
Lidija Korunovic ◽  
Ivan Anastasijevic
Keyword(s):  
Curve Fitting ◽  
Laboratory Experiments ◽  
Low Voltage ◽  
Supply Voltage ◽  
Nonlinear Load ◽  
Current Harmonics ◽  
Current Harmonic ◽  
Voltage Variation

The paper deals with the determination of current harmonic dependencies of some nonlinear load devices on the rms supply voltage. These dependencies are based on the laboratory experiments that include the variations of rms supply voltage in relatively wide ranges. The experiments were performed on some representatives of nonlinear load devices. Both current harmonic amplitudes and their angles are recorded during the voltage changes, and corresponding dependencies on rms voltage are obtained by curve fitting. The results are related to actual devices that are typically used in residential load sector. The obtained dependencies are the indices of potentially significant effects of rms voltage variation on current harmonics in low voltage installations.

Implementation of Single-Phase Two-Switch Midpoint Unidirectional Multilevel Converter System

2018 ◽  
Vol 19 (4) ◽  
Author(s):  
Peethala Rajiv Roy ◽  
P. Parthiban ◽  
B. Chitti Babu
Keyword(s):  
Single Phase ◽  
Pulse Width Modulation ◽  
Low Voltage ◽  
Supply Voltage ◽  
Harmonic Distortion ◽  
Input Voltage ◽  
Open Loop ◽  
Current Control ◽  
Control Technique ◽  
Control Scheme

Abstract This paper deals with implementation of a single-phase three level converter system under low voltage condition. The frequency of the switches is made constant and involves change in ${t_{on}}$ and ${t_{off}}$ duration. For this condition the pulse width modulation control scheme for a single phase three level rectifier is developed to improve the power quality. The hysteresis current control technique is adopted to bring forth three-level PWM on the dc side of the bridge rectifier and to achieve high power factor and low harmonic distortion. Based on the proposed control scheme, the line current is driven to follow the sinusoidal current command which is in phase with the supply voltage. By using three-level voltage pattern the blocking voltage of each power device is clamped to half of the dc link voltage. The simulation and experimental results of 20W converter under low input voltage condition are shown to verify the circuit performance. Open loop simulation and hardware tests are implemented by applying a low voltage of 15 V(rms) on the input side.

scholarly journals A Control Method for Balancing the SoC of Distributed Batteries in Islanded Converter-Interfaced Microgrids

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Spyros I. Gkavanoudis ◽  
Konstantinos O. Oureilidis ◽  
Georgios C. Kryonidis ◽  
Charis S. Demoulias
Keyword(s):  
Distributed Generation ◽  
Control Method ◽  
Low Voltage ◽  
Renewable Energy Sources ◽  
Intermediate Frequency ◽  
Nonlinear Loads ◽  
Time Duration ◽  
Detailed Simulation ◽  
Filter Operation ◽  
A Current

In a low-voltage islanded microgrid powered by renewable energy sources, the energy storage systems (ESSs) are considered necessary, in order to maintain the power balance. Since a microgrid can be composed of several distributed ESSs (DESSs), a coordinated control of their state-of-charge (SoC) should be implemented, ensuring the prolonged lifespan. This paper proposes a new decentralized control method for balancing the SoC of DESSs in islanded microgrids, without physical communication. Each DESS injects a current distortion at 175 Hz, when its SoC changes by 10%. This distortion is recognized by every DESS, through a phase-locked loop (PLL). In order to distinguish the origin of the distortion, each DESS injects a distortion of different time duration. This intermediate frequency has been selected in order to avoid the concurrence with the usual harmonics. The DESSs take advantage of this information and inject a current proportional to the SoC. Implementing this strategy, a comparable number of charging/discharging cycles for each DESS are achieved. Furthermore, an active filter operation, implemented in the dq rotating frame for each individual harmonic, is integrated in the control of the distributed generation units, supplying nonlinear loads with high-quality voltage. The effectiveness of this method is verified by detailed simulation results.

Modified DSTATCOM Topology with Reduced DC Link Voltage for Reactive and Harmonic Power Compensation of Unbalanced Nonlinear Load in Distribution System

2014 ◽  
Vol 15 (3) ◽  
pp. 263-277 ◽  
Author(s):  
Nagesh Geddada ◽  
Srinivas B. Karanki ◽  
Mahesh K. Mishra
Keyword(s):  
Distribution System ◽  
Experimental Studies ◽  
Current Control ◽  
Control Technique ◽  
Voltage Source ◽  
Nonlinear Loads ◽  
Nonlinear Load ◽  
Hysteresis Current Control ◽  
Switching Losses ◽  
Power Switches

Abstract This paper proposes a modified four-leg distribution static compensator (DSTATCOM) topology for compensation of unbalanced and nonlinear loads in three-phase four-wire distribution system. DSTATCOM, connected in parallel to the load, supplies reactive and harmonic powers demanded by unbalanced nonlinear loads. In this proposed topology, the voltage source inverter (VSI) of DSTATCOM is connected to point of common coupling (point of interconnection of source, load, DSTATCOM) through interface inductor and series capacitance, unlike the conventional topology which consists of interface inductor alone. Load compensation with a lower value of input DC link voltage of VSI is possible in this modified topology compared to conventional topology. A comparative study on modified and conventional topologies in terms of voltage rating of inverter power switches, switching losses in VSI and power rating of input DC capacitor of VSI is presented. The detailed design aspects of DC link capacitor and interface series capacitor are also presented. The reference filter currents are generated using instantaneous symmetrical component theory and are tracked using hysteresis current control technique. A detailed simulation study is carried out, to compare the compensation performances of conventional, modified topologies using PSCAD simulator and experimental studies are done to validate the simulation results.

scholarly journals Power Quality Enhancement of Grid-Connected Solar Photovoltaic System using ANN based Filter

2021 ◽  
Vol 7 (03) ◽  
pp. 84-89
Author(s):  
P Hari Pallavi and P Ankineedu Prasad
Keyword(s):  
Power Quality ◽  
Distribution System ◽  
Current Control ◽  
Photovoltaic System ◽  
Control Technique ◽  
Quality Level ◽  
Pv System ◽  
Nonlinear Load ◽  
Current Harmonics ◽  
Neural Network Controller

Grid-connected photovoltaic (PV) systems are increasingly attracting the attention of industry and academia as a means of providing an alternative to conventional fossil-fuel generation and pollution-free power. This project aims to improve the power quality level of a grid-tied PV distribution system using shunt active power filter (APF) along with adaptive current control technique. In this work Artificial Neural Network controller used to destroy the voltage and current harmonics in a grid-tied PV system. A reference current generation strategy is implemented to mitigate the current harmonics by extracting the fundamental constituents (FCs) from the nonlinear load currents. MCCF is employed to separate the FC from the distorted grid voltages and eliminates the voltage harmonics during extremely polluted grid voltage condition. The comparative analysis is analyzed to check the effectiveness of the proposed hybrid control scheme with existing and adaptive control techniques in respect of power quality, better dc offset rejection, better FC and frequency extraction, and grid synchronization.

scholarly journals Power Quality Enhancement of Grid-Connected Solar Photovoltaic System Using ANN based Filter

2021 ◽  
Vol 7 (03) ◽  
pp. 101-106
Author(s):  
B Anand Swaroop and K Jagadeesh
Keyword(s):  
Power Quality ◽  
Distribution System ◽  
Fuzzy Logic Controller ◽  
Current Control ◽  
Photovoltaic System ◽  
Control Technique ◽  
Quality Level ◽  
Pv System ◽  
Nonlinear Load ◽  
Current Harmonics

Grid-connected photovoltaic (PV) systems are increasingly attracting the attention of industry and academia as a means of providing an alternative to conventional fossil-fuel generation and pollution-free power. This project aims to improve the power quality level of a grid-tied PV distribution system using shunt active power filter (APF) along with adaptive current control technique. In this work Fuzzy Logic controller used to destroy the voltage and current harmonics in a grid-tied PV system. A reference current generation strategy is implemented to mitigate the current harmonics by extracting the fundamental constituents (FCs) from the nonlinear load currents. MCCF is employed to separate the FC from the distorted grid voltages and eliminates the voltage harmonics during extremely polluted grid voltage condition. The comparative analysis is analyzed to check the effectiveness of the proposed hybrid control scheme with existing and adaptive control techniques in respect of power quality, better dc offset rejection, better FC and frequency extraction, and grid synchronization.

scholarly journals Power Quality Enhancement of Grid-Connected Solar Photovoltaic System using ANN based Filter

2021 ◽  
Vol 7 (03) ◽  
pp. 84-89
Author(s):  
P Hari Pallavi and P Ankineedu Prasad
Keyword(s):  
Power Quality ◽  
Distribution System ◽  
Current Control ◽  
Photovoltaic System ◽  
Control Technique ◽  
Quality Level ◽  
Pv System ◽  
Nonlinear Load ◽  
Current Harmonics ◽  
Neural Network Controller

Grid-connected photovoltaic (PV) systems are increasingly attracting the attention of industry and academia as a means of providing an alternative to conventional fossil-fuel generation and pollution-free power. This project aims to improve the power quality level of a grid-tied PV distribution system using shunt active power filter (APF) along with adaptive current control technique. In this work Artificial Neural Network controller used to destroy the voltage and current harmonics in a grid-tied PV system. A reference current generation strategy is implemented to mitigate the current harmonics by extracting the fundamental constituents (FCs) from the nonlinear load currents. MCCF is employed to separate the FC from the distorted grid voltages and eliminates the voltage harmonics during extremely polluted grid voltage condition. The comparative analysis is analyzed to check the effectiveness of the proposed hybrid control scheme with existing and adaptive control techniques in respect of power quality, better dc offset rejection, better FC and frequency extraction, and grid synchronization.

scholarly journals Determination of Inactive Powers in a Single-Phase AC Network

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4814
Author(s):  
Nickolay I. Shchurov ◽  
Sergey V. Myatezh ◽  
Boris V. Malozyomov ◽  
Alexander A. Shtang ◽  
Nikita V. Martyushev ◽  
...  
Keyword(s):  
Single Phase ◽  
Reactive Power ◽  
Supply Voltage ◽  
Time Base ◽  
Nonlinear Loads ◽  
Nonlinear Load ◽  
Voltage Curve ◽  
Current Curve ◽  
Definition Of

Based on the development of the theory of reactive power and distortion power, starting with the works of Fryze and Budeanu, it has been found that the contradictions in the definition of the components of inactive powers are caused by errors in the introduced intermediate concepts and corresponding calculations when switching to nonlinear and non-sinusoidal AC circuits. The materials of the works of modern researchers and the numerical calculations carried out made it possible to trace the differences between reactive power and distortion power, to confirm the orthogonality properties of the active, reactive power, and distortion power components. The paper defines the conditions for achieving a power balance in an AC network with nonlinear loads, compiled and tested criteria leading to the absence of distortion power in a single-phase AC network. Using the time base of the projection of the generalized vectors in vector diagrams, it is shown that compliance with the criteria for the absence of distortion power does not determine the mutual similarity of the voltage curve with the current curve for a nonlinear load. It has been found that the well-known term “distortion power” has an unfortunate wording, since this power, although it characterizes the interaction of harmonics of currents and voltages with different ordinal numbers, is not determined by the visual similarity or the degree of distortion of the load current waveforms relative to the supply voltage curve.

scholarly journals Nonlinear load modeling for analysis of non-sinusoidal conditions in electrical networks based on measurements of harmonic parameters

2021 ◽  
pp. 5-20
Author(s):  
L. Kovernikova ◽  
V.C. Luong
Keyword(s):  
Electrical Equipment ◽  
Distribution Functions ◽  
Operating Conditions ◽  
Electrical Network ◽  
Electrical Networks ◽  
Nonlinear Loads ◽  
Nonlinear Load ◽  
Current Harmonics ◽  
Load Models ◽  
Nonlinear Devices

Non-sinusoidal conditions in electrical networks need to be calculated for their control and development of technical measures to maintain harmonic parameters according to the requirements of regulatory documents. These calculations are impossible without electrical network and nonlinear load models that adequately reflect them in computational programs. Nonlinear load models have been developed for a long time. Some studies present general modeling principles and models of various nonlinear devices. Others consider some nonlinear devices as equivalent nonlinear loads connected to low and medium voltage networks. A whole host of high-power nonlinear electrical equipment is connected to high voltage networks. Modeling nonlinear loads connected to these networks is a problem. Research of measured parameters of harmonic conditions in electrical networks has shown that they are random values. The probabilistic nature is determined by the network configuration, a range of network components, the number of nonlinear loads, wave and frequency properties of the network, harmonic source phase currents, voltage at terminals of nonlinear electrical equipment, changes in operating conditions and load power, and many other factors. Nonlinear loads can only be modeled based on the measurements of parameters of harmonic conditions due to their unpredictability. The paper presents an overview of existing methods for modeling nonlinear loads, a methodological approach to modeling nonlinear loads based on measured parameters, an algorithm for modeling harmonics of active and reactive currents, a computational program algorithm designed to identify distribution functions of measured current harmonics, and modeling results for current harmonics of railway transformers supplying power to electric locomotives.

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