scholarly journals Coordinate Control of Power/Current for Grid-Connected Inverter Based on PCI Controller under Unbalanced Grid Conditions

Complexity ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Chencong Zhao ◽  
Jun Liu ◽  
Zhouhua Xie ◽  
Feihang Zhou
Keyword(s):  
Output Power ◽  
Control Strategy ◽  
Balance Control ◽  
Weight Coefficient ◽  
Current Harmonics ◽  
Coordinate Control ◽  
Harmonic Components ◽  
Grid Connected Inverter ◽  
Complex Integral ◽  
Unbalanced Grid

The oscillations on output power and distortion of the inverter currents will occur in the case of unbalanced grid voltage faults. Constant output power and good current quality cannot be achieved simultaneously. Aiming at these problems, a coordinate control strategy for suppressing power fluctuations and current harmonics is proposed by analyzing instantaneous power control and current balance control. The proposed control is achieved by adjusting the weight coefficient of current reference values to change the current harmonic contents based on proportional complex integral (PCI) controller and proportional multiple complex integral (PMCI) controller. The control strategy with a simple control structure neither needs to detect harmonic components of the inverter currents, nor needs to separate the positive and negative components of voltage and current, which is easy to be realized. The feasibility and effectiveness of the proposed control are verified by the comparison and analysis of simulation.

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.

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.

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.

scholarly journals A Modified Grid-Connected Inverter Topology for Power Oscillation Suppression under Unbalanced Grid Voltage Faults

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5057
Author(s):  
Cheng Luo ◽  
Xikui Ma ◽  
Lihui Yang ◽  
Yongming Li ◽  
Xiaoping Yang ◽  
...  
Keyword(s):  
Output Power ◽  
Output Current ◽  
Grid Voltage ◽  
Power Oscillation ◽  
Power Simulation ◽  
Point Of Common Coupling ◽  
In Series ◽  
Grid Connected Inverter ◽  
Output Filter ◽  
Unbalanced Grid

Under unbalanced grid voltage faults, the output power oscillation of a grid-connected inverter is an urgent problem to be solved. In the traditional topology of inverters, it is impossible to eliminate power oscillation and simultaneously maintain balanced output current waveform. In this paper, considering the solvability of reference current matrix equation, the inherent mechanism of inverter output power oscillation is analyzed, and a modified topology with auxiliary modules inserted in series between the inverter output filter and the point of common coupling (PCC) is proposed. Due to the extra controllable freedoms provided by auxiliary modules, the inverter could generate extra voltage to correct PCC voltage while keeping balance of output current, so as to eliminate the oscillation of output power. Simulation and experimental results verify the effectiveness of the proposed topology.

Modified Power Compensation Control Strategy of Three-Phase Grid-Connected Inverter under Unbalanced Grid Voltage Conditions

2015 ◽  
Vol 740 ◽  
pp. 335-338 ◽  
Author(s):  
Shao Hua Sun ◽  
Hong Qi Ben
Keyword(s):  
Control Strategy ◽  
Reactive Power ◽  
Positive Sequence ◽  
Grid Voltage ◽  
Compensation Control ◽  
Active And Reactive Power ◽  
Three Phase ◽  
Grid Connected Inverter ◽  
Three Phase Inverter ◽  
Unbalanced Grid

Control strategy under unbalanced grid voltage conditions is one of the most important issues for grid-connected inverter. Under unbalanced grid voltage conditions, the 2nd active and reactive power ripples generate, they pollute the grid. To meet the demands of IEEE Std.929-2000, this paper proposed a modified power compensation control strategy; the proposed solution is based on direct power control. To provide accurate compensating power, the power model of three-phase inverter under unbalanced grid voltage conditions is given, using the positive sequence current component and the negative sequence voltage component, the compensating powers are calculated in details. Theoretical analysis and comparative simulation verification are presented to demonstrate the effectiveness of the proposed control strategy.

A Reference Compensation Current Control of Grid-Connected Inverter for Three-Phase Distributed Generators

2013 ◽  
Vol 433-435 ◽  
pp. 1183-1187 ◽  
Author(s):  
Shao Ru Zhang ◽  
Shao Yuan Li
Keyword(s):  
Control Strategy ◽  
Distribution Systems ◽  
Reactive Power ◽  
Neutral Current ◽  
Power Converter ◽  
Active Power ◽  
Current Control ◽  
Renewable Energy Resources ◽  
Current Harmonics ◽  
Grid Connected Inverter

Renewable energy resources (RES) are being increasingly connected in distribution systems by utilizing power electronic converters. However, the extensive use of power electronics has resulted in a rise in power quality (PQ) concerns faced by the utility. A novel control strategy implementing reference compensation current was proposed in this paper. So that these grid-connected inverters can achieve maximum benefits when they installed in 3-phase 4-wire distribution systems. The inverter is controlled to perform as a multi-function device by incorporating active power filter functionality. The inverter can thus be utilized as: 1) power converter to transfer active power from RES to the grid, and 2) load reactive power demand support; 3) current harmonics compensation at PCC; and 4) current unbalance and neutral current compensation in case of 3-phase 4-wire system. Moreover, with adequate control of grid-interfacing inverter, all the four objectives can be accomplished either individually or simultaneously. Simulation results show the validity and capability of the novel proposed control strategy.

scholarly journals Flexible Control Strategy for Grid-Connected Inverter Under Unbalanced Grid Faults Without PLL

2015 ◽  
Vol 30 (4) ◽  
pp. 1773-1778 ◽  
Author(s):  
Xiaoqiang Guo ◽  
Wenzhao Liu ◽  
Xue Zhang ◽  
Xiaofeng Sun ◽  
Zhigang Lu ◽  
...  
Keyword(s):  
Control Strategy ◽  
Flexible Control ◽  
Grid Connected Inverter ◽  
Unbalanced Grid

Control for Grid Connected Inverter under Unbalanced Grid Voltage Based on PI-QR Controller

2014 ◽  
Vol 716-717 ◽  
pp. 1648-1653
Author(s):  
Jia Jin Pan ◽  
Yan Cheng Liu ◽  
Chuan Wang ◽  
Qin Jin Zhang
Keyword(s):  
Reference Frame ◽  
Control Strategy ◽  
Control Model ◽  
Grid Voltage ◽  
Synchronous Reference Frame ◽  
Distorted Grid ◽  
Control Scheme ◽  
Grid Connected Inverter ◽  
Typical Model ◽  
Unbalanced Grid

Control strategy under unbalanced and distorted grid voltage is one of the most significant tasks for grid-connected inverter (GCI). In order to guarantee that the grid current meets the related IEEE Std.929-2000, a new control scheme was presented. Firstly, the typical model of GCI was presented. Secondly, the GCI control model based on PI-QR controller in synchronous reference frame (SRF) was built. Finally, the system’s simulation was conducted under distorted and unbalanced grid voltage. The results demonstrate the effectiveness of the presented control strategy.

Sign in / Sign up

Export Citation Format

Share Document