scholarly journals Enhanced Control Scheme for a Three-Phase Grid-Connected PV Inverter under Unbalanced Fault Conditions

Electronics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1247
Author(s):  
Saeid Abbasi ◽  
Ali Asghar Ghadimi ◽  
Amir Hossein Abolmasoumi ◽  
Mohammad Reza Miveh ◽  
Francisco Jurado
Keyword(s):  
Reactive Power ◽  
Control Strategies ◽  
Active Power ◽  
Reactive Control ◽  
Pv System ◽  
Pv Inverter ◽  
Three Phase ◽  
Control Scheme ◽  
Double Grid ◽  
Unbalanced Grid

This paper presents an improved control strategy to cancel the double grid frequency oscillations in the active power, reactive power, and DC-link voltage of a three-phase grid-connected photovoltaic (PV) system under unbalanced grid condition. To achieve these goals, an enhanced positive–negative-sequence control (PNSC) to remove oscillations of active power and an instantaneous active–reactive control (IARC) to mitigate the fluctuations of active and reactive power, simultaneously, are suggested. These methods are also effective to reduce the oscillations of the DC-link voltage. To track the desired unbalanced or harmonic reference currents, improved proportional resonant (PR) current controllers have been designed using the Bode frequency analysis. Simulation studies are carried out via Matlab/Simulink® software to verify the effectiveness of the suggested control strategies.

scholarly journals Simulation Models For Three-Phase Grid Connected PV Inverters Enabling Current Limitation Under Unbalanced Faults

2020 ◽  
Vol 10 (2) ◽  
pp. 5396-5401 ◽  
Author(s):  
L. H. Lam ◽  
T. D. H. Phuc ◽  
N. H. Hieu
Keyword(s):  
Reactive Power ◽  
Simulation Models ◽  
Pv System ◽  
Grid Voltage ◽  
Pv Systems ◽  
Three Phase ◽  
Sinusoidal Current ◽  
Grid Connected Converters ◽  
Double Grid ◽  
Unbalanced Grid

Normally unbalanced grid voltage dips may lead to unbalanced non-sinusoidal current injections, DC-link voltage oscillations, and active and/or reactive power oscillations with twice the grid fundamental frequency in three-phase grid-connected Photovoltaic (PV) systems. Double grid frequency oscillations at the DC-link of the conventional two-stage PV inverters can further deteriorate the DC-link capacitor, which is one of the most important limiting components in the system. Proper control of these converters may efficiently address this problem. In such solutions, Current Reference Calculation (CRC) is one of the most important issues that should be coped with the reliable operation of grid-connected converters under unbalanced grid faults. Therefore, this paper proposes and simulates CRC methods and presents the results in order to improve the quality of the grid-connected PV system under unbalanced grid voltage fault.

scholarly journals Hysteresis Control for Shunt Active Power Filter under Unbalanced Three-Phase Load Conditions

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Z. Chelli ◽  
R. Toufouti ◽  
A. Omeiri ◽  
S. Saad
Keyword(s):  
Reactive Power ◽  
Harmonic Distortion ◽  
Active Power Filter ◽  
Active Power ◽  
Harmonic Suppression ◽  
Nonlinear Loads ◽  
Shunt Active Power Filter ◽  
Power Filter ◽  
Three Phase ◽  
Control Scheme

This paper focuses on a four-wire shunt active power filter (APF) control scheme proposed to improve the performance of the APF. This filter is used to compensate harmonic distortion in three-phase four-wire systems. Several harmonic suppression techniques have been widely proposed and applied to minimize harmonic effects. The proposed control scheme can compensate harmonics and reactive power of the nonlinear loads simultaneously. This approach is compared to the conventional shunt APF reference compensation strategy. The developed algorithm is validated by simulation tests using MATLAB Simulink. The obtained results have demonstrated the effectiveness of the proposed scheme and confirmed the theoretical developments for balanced and unbalanced nonlinear loads.

scholarly journals Modeling and simulation of three phases cascaded H-bridge grid-tied PV inverter

2019 ◽  
Vol 8 (1) ◽  
pp. 1-9
Author(s):  
Swetapadma Panigrahi ◽  
Amarnath Thakur
Keyword(s):  
Control Strategy ◽  
Pi Controller ◽  
Pv System ◽  
Grid Current ◽  
Pv Array ◽  
Pv Inverter ◽  
Simulink Model ◽  
Three Phase ◽  
Control Scheme ◽  
Mppt Controller

In this paper a control scheme for three phase seven level cascaded H-bridge inverter for grid tied PV system is presented. As power generation from PV depends on varing environmental conditions, for extractraction of maximum power from PV array, fuzzy MPPT controller is incorporated with each PV array. It gives fast and accurate response. To maintain the grid current sinusoidal under varying conditions, a digital PI controller scheme is adopted. A MATLAB/Simulink model is developed for this purpose and results are presented. At last THD analysis is carried out in order to validate the performance of the overall system. As discussed, with this control strategy the balanced grid current is obtained keeping THD values with in the specified range of IEEE-519 standard.

scholarly journals The Reactive Power Support Strategy based on Dual-loop Control for Three-phase Grid-connected Inverter

2020 ◽  
Vol 182 ◽  
pp. 02011
Author(s):  
WAN Qian ◽  
Xia Chengjun ◽  
Azeddine Houari ◽  
Zhao Xue ◽  
Xia Chengjun ◽  
...  
Keyword(s):  
Control Strategy ◽  
Reactive Power ◽  
Low Voltage ◽  
Renewable Energy Sources ◽  
Active Power ◽  
Electric Power System ◽  
Pv System ◽  
Loop Control ◽  
Pv Array ◽  
Three Phase

Renewable energy sources (RESs) generally connected with electric power system via power electronic interface. This paper presents a reactive power and voltage (Q/V) control strategy of three-phase photovoltaic (PV) system to offering reactive power based on the typical dual-loop control topology. It is worth mentioning that control strategy can support reactive power when a low voltage fault occurs in AC bus without additional compensation device. With the help of the decoupling control, the PV array can generate active power as much as possible in variable external solar radiation conditions. The voltage of PV arrays is adopted as the objective, which on account of the easy availability and controllability of voltage, to control output active power. Besides, accurately modeling process from a PV cell to PV array is described in the beginning to acquire the P-V and V-I characteristics of PV arrays, which promote the designment of Q/V control.

scholarly journals Reactive Power Control of Single-Stage Three-Phase Photovoltaic System during Grid Faults Using Recurrent Fuzzy Cerebellar Model Articulation Neural Network

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Faa-Jeng Lin ◽  
Kuang-Chin Lu ◽  
Hsuan-Yu Lee
Keyword(s):  
Neural Network ◽  
Power Control ◽  
Reactive Power ◽  
Single Stage ◽  
Pv System ◽  
Reactive Power Control ◽  
Active And Reactive Power ◽  
Three Phase ◽  
Control Scheme ◽  
Reactive Current

This study presents a new active and reactive power control scheme for a single-stage three-phase grid-connected photovoltaic (PV) system during grid faults. The presented PV system utilizes a single-stage three-phase current-controlled voltage-source inverter to achieve the maximum power point tracking (MPPT) control of the PV panel with the function of low voltage ride through (LVRT). Moreover, a formula based on positive sequence voltage for evaluating the percentage of voltage sag is derived to determine the ratio of the injected reactive current to satisfy the LVRT regulations. To reduce the risk of overcurrent during LVRT operation, a current limit is predefined for the injection of reactive current. Furthermore, the control of active and reactive power is designed using a two-dimensional recurrent fuzzy cerebellar model articulation neural network (2D-RFCMANN). In addition, the online learning laws of 2D-RFCMANN are derived according to gradient descent method with varied learning-rate coefficients for network parameters to assure the convergence of the tracking error. Finally, some experimental tests are realized to validate the effectiveness of the proposed control scheme.

scholarly journals Implementation of Solar-PV Inverter as STATCOM during Nighttime in Grid-Connected System (PV-STATCOM)

2020 ◽  
Vol 15 (3) ◽  
pp. 411-419
Author(s):  
Indraman Tamrakar ◽  
Kishor Joshi ◽  
Pranisha Karki ◽  
Sagar Bimali ◽  
Tara Aryal
Keyword(s):  
Reactive Power ◽  
Current Trend ◽  
Active Power ◽  
Solar Pv ◽  
Control Logic ◽  
Pv System ◽  
Night Time ◽  
Power Generator ◽  
Pv Inverter ◽  
Solar Pv System

Grid-connected PV-system generates active power only during daytime and it remains completely idle or sleeping during nighttime.In an interconnected power system balance between active and reactive power consumption and generation is very essential tomaintain the frequency and voltage constant. The current trend is that the reactive Power is either supplied by generators or by separatereactive Power compensators such and shunt capacitor, STATCOM, etc. If the grid needs reactive power during night time, thesleeping inverter of the solar-PV system can be used as a reactive power generator without exceeding the volt-amp rating of theinverter and this scheme is named PV-STATCOM in this paper.This paper presents the concept of PV-STATCOM and its control logic. The inverter of the grid-connected Solar-PV system acts asan active power generator during daytime and reactive power generator during nighttime. The proposed scheme is simulated inMATLAB Simulink and the simulation results are presented. The simulation result shows that the proposed control logic for PV-STATCOM works satisfactorily.

Reactive Power Compensation for Unbalanced Fluctuating Loads by Using Two-Dimensional Space Vector and a Static Var Compensator

2014 ◽  
Vol 533 ◽  
pp. 397-400 ◽  
Author(s):  
Chi Jui Wu ◽  
Yu Wei Liu ◽  
Shou Chien Huang
Keyword(s):  
Power Factor ◽  
Reactive Power ◽  
Dimensional Space ◽  
Measurement Data ◽  
Power Source ◽  
Active Power ◽  
Two Dimensional ◽  
Static Var Compensator ◽  
Space Vector ◽  
Three Phase

To modify the power factor and balance the three-phase currents simultaneously, this paper proposes the instantaneous compensator to calculate the compensation current. The instantaneous compensator utilizes two-dimensional instantaneous space vector and setting the active power as a constant for each cycle which can improve power quality effectively. Moreover, the instantaneous compensator requires an independent power source, whose capacity can be reduce by using a static var compensator (SVC). An SVC does not interfere with the capability of the instantaneous compensator. Field measurement data were analyzed. Simulation results confirmed the feasibility of correcting the power factor and balancing load currents simultaneously using the proposed method.

A New Control Scheme for Three-Phase Non-Isolated Grid Feeding PV Inverter

2021 ◽  
Author(s):  
Sumaya Jahan ◽  
Shuvra Prokash Biswas ◽  
Md Kamal Hosain ◽  
Md Rabiul Islam ◽  
Md Moktadir Rahman ◽  
...  
Keyword(s):  
Pv Inverter ◽  
Three Phase ◽  
Control Scheme

scholarly journals Optimal P-Q Control of Grid-Connected Inverters in a Microgrid Based on Adaptive Population Extremal Optimization

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2107 ◽  
Author(s):  
Min-Rong Chen ◽  
Huan Wang ◽  
Guo-Qiang Zeng ◽  
Yu-Xing Dai ◽  
Da-Qiang Bi
Keyword(s):  
Constrained Optimization ◽  
Optimization Problem ◽  
Reactive Power ◽  
Active Power ◽  
Adaptive Genetic Algorithm ◽  
Constrained Optimization Problem ◽  
Extremal Optimization ◽  
Active And Reactive Power ◽  
Three Phase ◽  
Grid Connected Inverter

The optimal P-Q control issue of the active and reactive power for a microgrid in the grid-connected mode has attracted increasing interests recently. In this paper, an optimal active and reactive power control is developed for a three-phase grid-connected inverter in a microgrid by using an adaptive population-based extremal optimization algorithm (APEO). Firstly, the optimal P-Q control issue of grid-connected inverters in a microgrid is formulated as a constrained optimization problem, where six parameters of three decoupled PI controllers are real-coded as the decision variables, and the integral time absolute error (ITAE) between the output and referenced active power and the ITAE between the output and referenced reactive power are weighted as the objective function. Then, an effective and efficient APEO algorithm with an adaptive mutation operation is proposed for solving this constrained optimization problem. The simulation and experiments for a 3kW three-phase grid-connected inverter under both nominal and variable reference active power values have shown that the proposed APEO-based P-Q control method outperforms the traditional Z-N empirical method, the adaptive genetic algorithm-based, and particle swarm optimization-based P-Q control methods.

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