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

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.

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.

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.

scholarly journals Control Strategy for a Grid-Connected Inverter under Unbalanced Network Conditions—A Disturbance Observer-Based Decoupled Current Approach

Energies ◽  
2017 ◽  
Vol 10 (7) ◽  
pp. 1067 ◽  
Author(s):  
Emre Ozsoy ◽  
Sanjeevikumar Padmanaban ◽  
Lucian Mihet-Popa ◽  
Viliam Fedák ◽  
Fiaz Ahmad ◽  
...  
Keyword(s):  
Control Strategy ◽  
Disturbance Observer ◽  
Current Approach ◽  
Grid Connected Inverter ◽  
Unbalanced Network

Performance Improvement of SVPWM-Based Three-Phase Grid-Connected Inverters

2013 ◽  
Vol 732-733 ◽  
pp. 1261-1264
Author(s):  
Zhi Lei Yao ◽  
Lan Xiao ◽  
Jing Xu
Keyword(s):  
Dynamic Response ◽  
Control Strategy ◽  
Pulse Width Modulation ◽  
Control Method ◽  
Grid Current ◽  
Current Controller ◽  
Three Phase ◽  
Reference Grid ◽  
Grid Connected Inverter

An improved control strategy for three-phase grid-connected inverters with space vector pulse width modulation (SVPWM) is proposed. When the grid current contains harmonics, the d-and q-axes grid currents is interacted in the traditional control method, and the waveform quality of the grid current is poor. As the reference output voltage cannot directly reflect the change of the reference grid current with the traditional control strategy, the dynamic response of the grid-connected inverter is slow. In order to solve the aforementioned problems, the d-and q-axes grid currents in the decoupled components of the grid current controller are substituted by the d-and q-axes reference grid currents, respectively. The operating principles of the traditional and proposed control methods are illustrated. Experimental results show that the grid-connected inverter with the improved control strategy has high waveform quality of the grid current and fast dynamic response.

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