scholarly journals Research on Harmonic Problem of Micro-grid with Distributed Grid Connected Inverter

Author(s):  
Xiangzheng Zhao ◽  
Dongmei Zhao
2018 ◽  
Vol 22 (Suppl. 2) ◽  
pp. 401-408
Author(s):  
Xiaohong Hao ◽  
Huimin Wang ◽  
Bei Peng ◽  
Zhi Yao ◽  
Yixiong Wang ◽  
...  

Renewable energy, distributed generation, and micro-grid technology have been widely concerned for a long time. The traditional grid-connected inverter control strategy does not take into account the problem of inertia which is short and fast to cause the frequency change. The virtual synchronous generator control strategy is adopted to simulate the synchronous generator characteristics, which enhanced the inertia and damp of the system. For the micro-grid of wind power grid-connected, the storage battery is arranged on the AC side of the permanent magnet direct-drive wind turbine, and the model of the virtual synchronous generator is established. Thus the grid-connected performance of large-scale wind farm is improved. Here, the effect of moment of inertia in the virtual synchronous generator and the grid-connected regulation of virtual synchronous generator are verified by using PSCAD/EMTDC. The simulation results show that the grid-connected inverter controlled by the virtual synchronous generator is approximately equivalent to the synchronous generator in external characteristic. The grid-connected inverter based virtual synchronous generator control has a beneficial to adjust frequency and voltage, and can enhance the standby inertia of new energy and grid power generation


2021 ◽  
Vol 2136 (1) ◽  
pp. 012032
Author(s):  
Shengqing Li ◽  
Wang Han ◽  
Xiaobao Li ◽  
Zhijian Wang

Abstract To address the serious harmonic problem of grid connected current in photovoltaic grid-connected inverter, a harmonic suppression strategy based on Repetitive and PI control is proposed in this thesis. According to this strategy, the mathematical model of LCL photovoltaic grid-connected inverter is established with the harmonic mechanism analyzed, the repetitive and PI control is added into the current controller, and the capacitive-current feedback is added to enhance the system damping. Furthermore, it puts PI control on the inner loop and the repetitive control on the outer loop to improve the dynamic performance and achieve the harmonic suppression of the system. Moreover, the simulation results show that this method improves the dynamic response ability of the system, and effectively suppress the grid-connected current harmonics as THD of grid-connected current is 19.65% lower than that of PI controller.


2008 ◽  
Vol 128 (2) ◽  
pp. 199-206
Author(s):  
Yusuke Kondo ◽  
Takeyoshi Kato ◽  
Yasuo Suzuoki ◽  
Toshihisa Funabashi

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