scholarly journals Composite Control Strategy of Output Current of LCL Photovoltaic Grid-Connected Inverter

2021 ◽  
Vol 2136 (1) ◽  
pp. 012015
Author(s):  
Shengqing Li ◽  
Xinluo Li ◽  
Qiang Wu ◽  
Xiafei Long
Keyword(s):  
Control Strategy ◽  
Block Diagram ◽  
Harmonic Distortion ◽  
Harmonic Suppression ◽  
Output Current ◽  
Control Block ◽  
Current Harmonics ◽  
Suppression Effect ◽  
Composite Control ◽  
Grid Connected Inverter

Abstract In order to further optimize the output current harmonic suppression effect of photovoltaic grid-connected inverters, a composite control strategy of LCL type photovoltaic grid-connected inverter output current is proposed. This strategy combines proportional complex integral (PCI) control and repetitive control (RC) in parallel, draws a composite control block diagram, introduces a transfer function, and designs PCI and RC control parameters. Prove that the compound control can reduce current harmonics, achieved the purpose of reducing the steady-state error of the fundamental frequency. And adopts a new PCI composite control strategy, which helps to save the cost of the control system. By building the MATLAB/Simulink simulation platform and establishing the PCI+RC composite control model of LCL photovoltaic grid-connected inverter, the comparison of the simulation results shows that compared with the PI+RC control strategy, the total harmonic distortion rate of the grid-connected current is reduced by 25.77. %, significantly improving the quality of grid-connected current.

A Method of Harmonic Current Suppression in Photovoltaic Grid-Connected Systems

2013 ◽  
Vol 303-306 ◽  
pp. 1145-1148
Author(s):  
Jia Guo ◽  
Zhi Gang Li ◽  
Ya Ping Cheng ◽  
Kai Huang ◽  
Chun Yan Cui
Keyword(s):  
Control Strategy ◽  
Current Waveform ◽  
Output Current ◽  
Harmonic Current ◽  
Current Harmonics ◽  
Waveform Control ◽  
Photovoltaic Power ◽  
Grid Connected Inverter ◽  
The Stability ◽  
Power Generation Systems

The grid-connected inverter plays an important role in the photovoltaic power generation systems, the output of the grid current harmonics affect the stability of the grid. The reason of grid inverter output current distortion, a detailed analysis of current waveform control strategy and its effectiveness of the grid-connected inverter harmonic current suppression is introduced based on the d-q coordinates in this paper.

A Study of Novel Cuk Grid-Connected Inverter Based on Double-Loop Control

2013 ◽  
Vol 846-847 ◽  
pp. 543-546
Author(s):  
Yue Zhou
Keyword(s):  
Control Strategy ◽  
Topological Structure ◽  
Double Loop ◽  
Output Current ◽  
Loop Control ◽  
Current Harmonics ◽  
New Type ◽  
Parallel Circuit ◽  
Parallel Input ◽  
Grid Connected Inverter

A kind of Cuk grid-connected inverter is proposed for renewable energy power generation. The grid-connected inverter using Cuk input series output parallel circuit, form a new type of non isolated single stage output parallel input series double Cuk inverter circuit. Firstly, On the basis of the topological structure and principle, the double-loop control strategy is researched to enhance its adaptability and robustness. Simulative results show that,the proposed inverter with double-loop control has better dynamic and static performances, with less output current harmonics and better waveform quality.

A multi-valve controlled saturable reactor and its harmonic optimization

2014 ◽  
Vol 33 (4) ◽  
pp. 1346-1365 ◽  
Author(s):  
Yifan Wang ◽  
Guozhu Chen
Keyword(s):  
Mathematical Model ◽  
Harmonic Analysis ◽  
Harmonic Distortion ◽  
Iron Core ◽  
Harmonic Suppression ◽  
Output Current ◽  
Harmonic Compensation ◽  
Content Type ◽  
Current Harmonics ◽  
The Mathematical Model

Purpose – As arc suppression coils (ASCs), magnetically controlled reactors (MCRs) are usually operated in the single-phase mode. Due to the lack of a third order harmonic compensation circuit, the current harmonics are high. The purpose of this paper is to propose a novel structure of MCR and a genetic algorithm (GA) to determine the parameters which will result in minimum total harmonics. Design/methodology/approach – This paper proposes the structure and the working principle of the multi-valve controlled saturable reactor (MCSR). There are several sorts of magnetic valves in the iron cores of the MCSR. The saturation degree of each magnetic valve is different when the same direct component of the magnetic flux is generated in the iron core, therefore current harmonics of different phases emerging, i.e. the total harmonics can be reduced. The magnetization characteristics and the mathematical model of the current harmonics of the MCSR are presented by introducing three parameters. The optimal values of the parameters that result in the smallest total harmonic distortion in the output current are calculated by a GA. Findings – The simulation and experimental results are coincident with the theoretical analyses, which prove the effectiveness of the proposed method on harmonic suppression. Practical implications – The method proposed in this paper can successfully reduce the current harmonics of the conventional MCR, including but not limited to the ASC. A prototype MCSR (540 kVA/10 kV) has been designed and constructed. Originality/value – In this paper, a MCSR is proposed. The mathematical model of the MCSR for harmonic analysis is developed. The optimal parameters that result in the smallest THD in the output current are calculated. The mathematical model can be also used for the harmonic analysis of conventional MCRs.

PI and Fuzzy-Controlled 3-Phase 4-Wire Interleaved Buck Active Power Filter with Shoot-Through Elimination for Power Quality Improvement using RTDS Hardware

2014 ◽  
Vol 15 (2) ◽  
pp. 177-194 ◽  
Author(s):  
Anup Kumar Panda ◽  
Ranjeeta Patel
Keyword(s):  
Control Strategy ◽  
Fuzzy Logic Controller ◽  
Supply Voltage ◽  
Harmonic Distortion ◽  
Active Power Filter ◽  
Active Power ◽  
Current Harmonics ◽  
Power Filter ◽  
Power Quality Improvement ◽  
Real Time Digital Simulator

Abstract In this paper, shoot-through current elimination DC–AC converter circuit has been presented with the application of active power filter (APF). The intuitive analysis of the shoot-through in the conventional DC–AC converter has been reported first. Interleaved buck (IB) converter is adopted to eliminate the shoot-through current, thereby increasing the reliability of the interleaved buck–based active power filter (IB-APF). The 3-phase 4-wire IB-APF eliminates the current harmonics produced by the load just as a conventional one does and are innately immune to “shoot-through” phenomenon, with the elimination of special protection features required in conventional inverter circuits. A comparison has been made about the compensation capabilities of the IB-APF with the PI and fuzzy logic controller (FLC) used by id–iq control strategy under different supply voltage conditions. The id–iq control strategy used for extracting the three-phase reference current for IB-APF, evaluating their performance here in MATLAB/Simulink environment and also implemented using real-time digital simulator hardware (OPAL-RT hardware). The RTDS result verifies that the total harmonic distortion percentage of the source current can be reduced below 5% according to IEEE-519 standard recommendations on harmonic limits.

scholarly journals A Novel Control Strategy for Grid-Connected Inverter Based on Iterative Calculation of Structural Parameters

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3306 ◽  
Author(s):  
Zhenao Sun ◽  
Dazhi Wang ◽  
Tianqing Yuan ◽  
Zairan Liu ◽  
Jiahui Yu
Keyword(s):  
Control Strategy ◽  
Structural Parameters ◽  
Dynamic Performance ◽  
Open Loop ◽  
Output Current ◽  
Open Loop System ◽  
Iterative Calculation ◽  
Static Performance ◽  
Grid Connected Inverter ◽  
Pv Grid

A novel control strategy that is based on iterative calculation of structural parameters is proposed for grid-connected inverter in this paper. The proposed strategy has a good dynamic performance, which makes it particularly suitable for the application of PV grid-connected generation. First, a second-order discretization mathematical model of grid-connected inverter control is established in the dq frame. The corresponding relation between the control signal and the output current is deduced in formulas. Then, the values of structural parameters in the formulas can be obtained through iterative calculation, which can further reduce the amount of calculation. After several iteration cycles, the structural parameters are approximately equal to their actual values and the inverter can be controlled as an open-loop system with its dynamic performance optimized. At last, simulation and experiments are performed. The results show that the static performance of the proposed strategy is as good as that of the classical ones, but its dynamic performance is improved significantly.

Power Control of Photovoltaic Inverter under Unbalanced Grid Faults Considering Limits of Its Current Harmonics

2014 ◽  
Vol 960-961 ◽  
pp. 1356-1360 ◽  
Author(s):  
Yu Zhou ◽  
Zhi Yong Dai ◽  
Qiang Gang Wang ◽  
Ling Ye ◽  
Nian Cheng Zhou
Keyword(s):  
Power Control ◽  
Control Strategy ◽  
Reactive Power ◽  
Harmonic Distortion ◽  
Optimal Parameters ◽  
Current Harmonics ◽  
Power Characteristics ◽  
Active And Reactive Power ◽  
Fluctuation Amplitude ◽  
Unbalanced Grid

This paper studies the instantaneous output power characteristics of photovoltaic inverters and its flexible power control strategy under unbalanced grid faults. Then the optimal parameters model of the power control is established with minimum integrated fluctuation amplitude of the active and reactive power as a goal when the constraint of the output current harmonic distortion of photovoltaic inverters is taken into account. Finally, the optimal power control of photovoltaic inverters based on dead-beat current tracking is realized and the feasibility of the proposed control strategy is verified with the power system transient software PSCAD/EMTDC.

Nonlinear Unbalanced Load Compensation for PV Sourced Grid Connected Inverter

2013 ◽  
Vol 768 ◽  
pp. 308-312
Author(s):  
P. Sivakumar ◽  
M. Jeevitha
Keyword(s):  
Harmonic Distortion ◽  
Irradiation Condition ◽  
Pv System ◽  
Current Harmonics ◽  
Load Compensation ◽  
Synchronous Reference Frame ◽  
Unbalanced Load ◽  
Grid Connected Inverter ◽  
Non Linear Load ◽  
Power Point

The major problem in the PV system is the poor PV consumption under viable irradiation condition. So in order to improve the power consumption of PV along with grid connected inverter, this system has been implemented with controller analysis and model. This system is mainly used for non linear load compensation under unbalanced condition. In the existing method, Peak current of the inverter is reduced during the unbalanced grid-voltage sags with the help of current harmonics injection which increases the total harmonic distortion. Double synchronous reference frame technique with PLL is used to synchronize PV with grid. As well as the maximum power point of PV is tracked using Incremental Conductance technique to reduce the error and improves the system efficiency. Selected simulation results using MATLAB/Simulink are reported in order to show the proposed system efficient.

Decoupled Control Strategy of Grid Interactive Inverter System with Optimal LCL Filter Design

2013 ◽  
Vol 14 (5) ◽  
pp. 477-486 ◽  
Author(s):  
B. Chitti Babu ◽  
Anup Anurag ◽  
Tontepu Sowmya ◽  
Debati Marandi ◽  
Satarupa Bal
Keyword(s):  
Control Strategy ◽  
Reactive Power ◽  
Filter Design ◽  
Dynamic Performance ◽  
Harmonic Distortion ◽  
Voltage Source ◽  
Lcl Filter ◽  
Current Harmonics ◽  
Switching Losses ◽  
Active And Reactive Power

Abstract This article presents a control strategy for a three-phase grid interactive voltage source inverter that links a renewable energy source to the utility grid through a LCL-type filter. An optimized LCL-type filter has been designed and modeled so as to reduce the current harmonics in the grid, considering the conduction and switching losses at constant modulation index (Ma). The control strategy adopted here decouples the active and reactive power loops, thus achieving desirable performance with independent control of active and reactive power injected into the grid. The startup transients can also be controlled by the implementation of this proposed control strategy: in addition to this, optimal LCL filter with lesser conduction and switching copper losses as well as core losses. A trade-off has been made between the total losses in the LCL filter and the Total Harmonic Distortion (THD%) of the grid current, and the filter inductor has been designed accordingly. In order to study the dynamic performance of the system and to confirm the analytical results, the models are simulated in the MATLAB/Simulink environment, and the results are analyzed.

scholarly journals PERANCANGAN INVERTER SATU FASA OFF-GRID MENGGUNAKAN DSPIC30F4011 DENGAN KONTROL ARUS METODE PROPORTIONAL RESONANT

TRANSIENT ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 753
Author(s):  
Segal Mancini Suroso ◽  
Iwan Setiawan ◽  
Bambang Winardi
Keyword(s):  
Power Plants ◽  
Harmonic Distortion ◽  
Current Control ◽  
System Response ◽  
Output Current ◽  
Current Output ◽  
Current Harmonics ◽  
Pv Systems ◽  
Bridge Type

The availability of fossil as fuel in conventional power plants is running low. This causes the use of renewable energy such as photovoltaic (PV) technology becomes very important. PV systems required inverters for converting DC voltage into AC voltage, where the quality of the inverter output current is very influential on the quality of power. Therefore, it is necessary to control the inverter current output which serves to improve the system response and minimize the current harmonics. In this research, a H-Bridge type of one phase Inverter is designed using 16-bit DSPIC30F4011 microcontroller with current control proportional resonant method. The inverter output current is fedback by the ACS712-05B current sensor. The test is carried out with the reference current range of 1 - 3 A on the load variation 7 Ω and 12 Ω. The test results show the actual current waveform of the inverter output is able to follow the reference current changes. Inductor value that not suitable and the effect of switching cause the ripple is still happening. The higher the output voltage of the inverter will result in the total current harmonic distortion becoming smaller.

scholarly journals An Improved Droop Control Strategy for Grid-connected Inverter Power Stability and Harmonic Suppression Under Grid Fluctuation and Inter-harmonics

2021 ◽  
Author(s):  
Wanwan Xu ◽  
Bin Wang ◽  
Jiang Liu ◽  
Da Li
Keyword(s):  
Control Strategy ◽  
Reactive Power ◽  
Control Strategies ◽  
Stability Control ◽  
Droop Control ◽  
Harmonic Suppression ◽  
Current Feedback ◽  
Pass Filter ◽  
Power Stability ◽  
Grid Connected Inverter

This paper presents an improved droop control strategy for grid-connected inverter power stability and power quality under distorted with consideration of grid fluctuation and inter-harmonics. An instantaneous frequency without PLL and amplitude of capacitor voltage feed-forward control strategy is given to power stability control, meanwhile a grid current feedback control is given by an incomplete derivation with a high-pass filter, so that the harmonics and inter-harmonics current can be suppressed. These approaches can provide both good active and reactive power dynamic response under fluctuation of frequency, and rejection ability against harmonic and inter-harmonic voltage. Based on model of inverter, the proposed control strategies are designed in detail. Simulations and experiments are present to validate the effectiveness of proposed method.

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