Accurate output power control of converters for microgrids based on local measurement and unified control????(Open Access)

作者：Mao, Meiqin^*; Dong, Zheng; Chang, Liuchen

来源：IEEJ Journal of Industry Applications, 2015, 4(4): 331-338.

DOI：10.1541/ieejjia.4.331

• Automatic switching
• Droop control
• Droop control method
• Improved control scheme
• Islanding operations
• Micro grid
• Output power controls
• Voltage compensation

Precise output power control and seamless transition of microsource converters (MSCs) between grid-tied and islanding operation modes are of great significance for the stability of voltage and frequency, and for power flow control in a microgrid. The wireless droop control method (WDCM) is an effective method for MSCs to share loads dynamically and automatically and realize the "plug and play"function. However, this method strongly relies on the local sampling signals of MSCs to dynamically control its output power. Therefore, the voltage drop induced by the line impedance will cause errors in the output power control of the MSCs and lead to system instability. To realize accurate power tracking and sharing, two virtual impedances and an on-line estimated power compensation conductance are proposed, which form a unified controller along with the refined droop control method and automatic voltage compensation mechanism. The proposed method enables the microgrid to realize automatic switching of the control objective when the operation mode changes, which ensures seamless transition between the different operation modes of the microgrid. This method is valid for all types of line impedances and loads. In addition, as the required voltage and current signals are sampled at the local output terminals of an MSC, the modularity and reliability of the controller is increased. Finally, the improved control scheme is verified via simulations and experiments.

• 出版日期2015
• 单位合肥工业大学