Parameter co-design of active damping loop and grid current controller for a 3-phase LCL-filtered grid-connected inverter

2021 ◽  
Vol 133 ◽  
pp. 107203
Author(s):  
Jianguo Lyu ◽  
Yiran Yan ◽  
Fuyun Wu ◽  
Zhuang Sun ◽  
Aamir Farooq ◽  
...  
Keyword(s):  
Active Damping ◽  
Grid Current ◽  
Current Controller ◽  
Grid Connected Inverter

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.

scholarly journals A Double Update PWM Method to Improve Robustness for the Deadbeat Current Controller in Three-Phase Grid-Connected System

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Ling Yang ◽  
Yandong Chen ◽  
An Luo ◽  
Kunshan Huai ◽  
Leming Zhou ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Characteristic Root ◽  
Response Speed ◽  
Current Control ◽  
System Stability ◽  
Grid Current ◽  
Current Controller ◽  
Three Phase ◽  
Grid Connected Inverter ◽  
Deviation Coefficient

In the grid-connected inverter based on the deadbeat current control, the filter inductance variation and single update PWM affect the distortion of the grid current, stability, and dynamic of the system. For this, a double update PWM method for the deadbeat current controller in three-phase grid-connected system is proposed, which not only effectively decreases the grid current distortion and control delay, but also improves the system stability and dynamic response speed due to reducing the characteristic root equation order of the closed-loop transfer function. The influence of the filter inductance deviation coefficient on the system performance is analyzed. As a conclusion, the corresponding filter inductance deviation coefficient in the system critical stability increases with increase in the parasitic resistance of the filter inductance and line equivalent resistance and decreases with increase in the sampling frequency. Considering the system stability and dynamic response, the optimal range of the control parameters is acquired. Simulation and experimental results verify the effectiveness of the proposed method.

scholarly journals A Control Parameters Design Method With Multi-Constrains for an LCL-Filtered Grid-Connected Inverter in a Weak Grid

2022 ◽  
Vol 9 ◽  
Author(s):  
Fuyun Wu ◽  
Zhuang Sun ◽  
Weiji Xu ◽  
Zhizhou Li ◽  
Jianguo Lyu
Keyword(s):  
Steady State ◽  
Design Method ◽  
Dynamic Performance ◽  
Active Damping ◽  
Parameter Design ◽  
Control Parameters ◽  
Weak Grid ◽  
Current Controller ◽  
Grid Impedance ◽  
Grid Connected Inverter

Under weak grid conditions, the variation of the grid impedance will affect the steady-state and dynamic performance of the LCL-filtered grid-connected inverter and even make the inverter unstable. To ensure the system stability and further improve the dynamic performance in a weak grid, a control parameter design method with multi-constrains considering the system bandwidth for the current controller and active damping is proposed in this paper. First, based on the current controller and active damping with only grid current feedback, the effects of control parameters and grid impedance on the LCL resonant suppression and the performance of the inverter are analyzed. Moreover, the parameter constraints of the controllers are derived considering the grid impedance, including stability, resonance suppression, and margin constraints. Furthermore, as the system bandwidth affects the dynamic performance of the inverter, combined with the obtained multi-constraints, the optimal control parameters are determined by achieving the maximum bandwidth of the system against the impedance variation. Compared with other two methods, when the proposed method is applied, the system can operate with a better dynamic and steady-state performance. Finally, experiments are performed on a 2 kW three-phase grid-connected inverter in the weak grid, which verify the effectiveness of the parameter design method proposed in this paper.

scholarly journals Research on Novel Control Strategy for Grid-Connected Inverter Suitable for Wide-Range Grid Impedance Variation

Electronics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 623 ◽  
Author(s):  
Xiaohuan Wang ◽  
Yang Liu ◽  
Xudong Zhang ◽  
Qingshou Yang ◽  
Chunjiang Zhang
Keyword(s):  
Control Strategy ◽  
Active Damping ◽  
Damping Coefficient ◽  
Current Loop ◽  
Grid Current ◽  
Impedance Variation ◽  
Grid Impedance ◽  
Wide Range ◽  
Simulation And Experiment ◽  
Grid Connected Inverter

With the higher penetration of renewable energy, the influence of grid equivalent distribution cable impedance on grid-connected inverter stability is attracting increasing attention. In order to suppress the interaction between grid distribution cable impedance and output impedance of the grid-connected system, the active damping strategy is often used. When a capacitive current loop is used, the damping coefficient increases with the grid impedance increasing. However, the excessive damping coefficient will cause the unstable operation of the system. In order to enhance the robustness of the system, a novel control strategy which is suitable for wide-range grid impedance variation is proposed. In this strategy, the capacitor current inner loop is combined with the grid current inner loop, and grid voltage feedforward is included. Since the virtual impedance, active damping and voltage feed-forward are normalized, the changing tendency of the damping coefficient of the grid-current inner loop is opposite to that of capacitor current inner-loop. The overall damping coefficient of the system remains relatively constant when the grid impedance changes, and this effectively suppresses the resonance of the system. In this paper, the method is analyzed and the parameters are designed and optimized. Finally, the simulation and experiment are presented to verify the analysis.

scholarly journals A novel current controller design for grid-integrated PV inverter system

2021 ◽  
Vol 3 (3) ◽  
Author(s):  
Ayaz Ahmad ◽  
L. Rajaji ◽  
A. Iqbal
Keyword(s):  
Controller Design ◽  
Vital Role ◽  
Current Feedback ◽  
Lcl Filter ◽  
Design Algorithm ◽  
Grid Voltage ◽  
Pv Inverter ◽  
Current Controller ◽  
Experimental Implementation ◽  
Grid Connected Inverter

AbstractDistributed generators are playing a vital role in supporting the grid in ever-increasing energy demands. Grid code regulation must be followed when integrating the photovoltaic inverter system to the grid. The paper investigates and analyzes a controller model for grid-connected PV inverters to inject sinusoidal current to the grid with minimum distortion. To achieve better tracking and disturbance rejection, a DSP-based current controller is designed with LCL filter. The controller gets the current feedback from the grid, compares it with reference current, and calculates duty cycle to generate PWM pulses to trigger H-bridge converters. The grid voltage is loaded to the initial value in proposed PR controller to ensure the initial inverter voltage to match the grid voltage. The paper presents a novel current controller algorithm for grid-connected inverter system, and simulation is done. A detailed analysis has been carried out to validate the proposed design algorithm. Experimental implementation of the current controller in the DC/AC converter circuits with an LCL filter is done for 5.4 kW to validate and match the simulation model.

DQ Transform Based Current Controller for Single-Phase Grid Connected Inverter

2018 ◽  
Author(s):  
Imanka Jayathilaka ◽  
Lushan Lakpriya ◽  
Damith De Alwis ◽  
Gayeshi Jayakody ◽  
K.T.M.U. Hemapala ◽  
...  
Keyword(s):  
Single Phase ◽  
Current Controller ◽  
Grid Connected Inverter
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