scholarly journals Research on LCL-type three-phase photovoltaic grid-connected inverter based on passive damping

2021 ◽  
Vol 2137 (1) ◽  
pp. 012017
Author(s):  
Yifeng Gu ◽  
Xianglian Xu ◽  
Xiaobei Yin ◽  
Yu He

Abstract The traditional LCL filter has resonance phenomenon in the working process of three-phase photovoltaic grid-connected inverter system. Based on the analysis of the frequency characteristics of LCL filter equivalent circuit before and after the introduction of passive damping resistor, it is concluded that the resonance of the system can be suppressed after the introduction of passive damping resistor. In the meantime, the current double closed-loop control strategy used in the system is introduced in detail. Finally, the simulation model is built by Matlab/Simulink simulation platform to verify the feasibility of the research method of LCL-type three-phase photovoltaic grid-connected inverter based on passive damping.

2018 ◽  
Vol 173 ◽  
pp. 02041
Author(s):  
Lin Chunxu ◽  
Zhou Chunhua ◽  
Li Wei ◽  
Chen Rui

In order to reduce the total harmonic distortion (THD) of the grid-connected current caused by the high-frequency switching of the inverter, this paper combines the high efficiency single-phase H6-type inverter with LCL filter. The double closed-loop control method that consists of grid-connected current outer loop and capacitor current inner loop is put forward, by which a resonance peak of a low damping LCL filter is eliminated. In the grid-connected current outer loop, quasi proportion resonant (QPR) controller is adopted to overcome the steady-state error and weak anti-jamming capability in traditional PI controller. Finally, a simulation model is built in SIMULINK to verify the research. The simulation results show that, based on the single-phase H6-type inverter and LCL filter, the double closed-loop QPR control strategy can achieve the static error free tracking control of grid-connected current, which makes the system more stable and reduces the THD of grid-connected current effectively.


2018 ◽  
Vol 54 (3A) ◽  
pp. 39
Author(s):  
Nguyen Trung Nhan

Exactly determining the control coefficients for the controller of a three-phase LCL-filter-based inverter is an important and challenging issue in microgrid systems. However, existing LCL-filter-based inverter systems usually assume that all system parameters are determined accurately and remain constant over time, which is not true in real situations. Variations in the system parameters are known to possibly seriously degrade the performance of LCL-filter-based inverter systems. For efficiency and robustness, this paper proposes a novel method for the generalized controller design of a three-phase LCL-filter-based grid-connected inverter system that can address deviations in system parameters. An optimum way to determine the stability bounds under various system parameters cases is introduced. The assessment of the stability bounds is based on the Routh criterion by solving the characteristic equation of the closed-loop control system. Simulations results are presented to validate the correctness and effectiveness of the proposed design method.


2013 ◽  
Vol 321-324 ◽  
pp. 917-920
Author(s):  
Guang Ya Liu ◽  
Xiao Song Li

Three-phase voltage source PWM rectifier generally adopts double closed loop control system. According to the high frequency characteristic of three-phase voltage source PWM rectifier, this paper put forward the setting method of current inner ring regulator and voltage outer ring regulator PI parameter. Finally, it is verified by simulation.


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