Stability analysis and research of DC microgrid based on improved adaptive drooping
Yu Lili1, Zhang Zhaoyun2, Liu Yitao1
1. School of Mechanical and Control Engineering, Shenzhen University, Shenzhen, Guangdong 518000; 2. School of Electronic Engineering, Dongguan University of Technology, Dongguan, Guangdong 523000
Abstract：In the DC microgrid, various distributed energy sources (photovoltaics, fans, energy storage units, etc.) are connected in parallel to the DC bus through inverters. Therefore, it is important to maintain the stability of the DC bus voltage and coordinate the energy management of the system. Since the impedance values of the distributed micro-power supplies in the DC microgrid to the AC/DC loads are not necessarily equal, here we assume the impedance values of the lines as virtual droop coefficients, which inevitably leads to the power output of each distributed micro-source relative to the load. Cannot be allocated as needed. Moreover, the power variation of the load causes the bus voltage to increase or decrease, which inevitably causes the DC bus voltage in the DC microgrid to fluctuate, affecting the stability of the entire system. Based on the above various factors, here we can adopt a method based on improved adaptive droop control, which takes into account the influence of line impedance and load fluctuations, and the mean value of voltage and current output through the converter. To equalize the output voltage and current value of each converter, the fluctuation range of the DC bus voltage value is reduced, and the current voltage distribution accuracy of each converter is indirectly improved. The modeling and simulation are carried out in combination with Matlab/Simulink. The simulation results can effectively verify the rationality of the proposed improved adaptive droop control strategy.
喻礼礼, 张兆云, 刘艺涛. 基于改进自适应下垂的直流微电网稳定分析与研究[J]. 电气技术, 2020, 21(5): 28-32.
Yu Lili, Zhang Zhaoyun, Liu Yitao. Stability analysis and research of DC microgrid based on improved adaptive drooping. Electrical Engineering, 2020, 21(5): 28-32.
[1] 曹鹏飞, 杨君, 饶纪全, 等. 分布式光伏发电网络构建与仿真[J]. 电气技术, 2019, 20(8): 64-68. [2] 宏健, 赵涛, 爱华. 用于直流微电网的改进型下垂控制策略[J]. 电气技术, 2019, 20(7): 1-4. [3] 赖一峰. 直流配电网的电压协同控制及稳定运行研究[J]. 电气技术, 2019, 20(7): 42-47. [4] 欣然, 崔曦文, 黄际元, 等. 电池储能电源参与电网一次调频的自适应控制策略[J]. 电工技术学报, 2019, 34(18): 3897-3908. [5] 谢文强, 韩民晓, 严稳利, 等. 功率负荷特性的直流微电网分级稳定控制策略[J]. 电工技术学报, 2019, 34(16): 3430-3443. [6] 刘子文, 苗世洪, 范志华, 等. 基于自适应下垂特性的孤立直流微电网功率精确分配与电压无偏差控制策略[J]. 电工技术学报, 2019, 34(4): 795-806. [7] 支娜, 张辉, 肖曦. 提高直流微电网动态特性的改进下垂控制策略研究[J]. 电工技术学报, 2016, 31(3): 31-39. [8] 麻常辉, 潘志远, 刘超男, 等. 基于自适应下垂控制的风光储微网调频研究[J]. 电力系统保护与控制, 2015, 43(23): 21-27. [9] Y Fu Z Z, Li F. Droop control for DC multi-microgrids based on local adaptive fuzzy approach and global power allocation correction[J]. in IEEE Transactions on Smart Grid, Sept, 2019, 10(5): 5468-5478. [10] Belal E K, Yehia D M, Azmy A M.Adaptive droop control for balancing SOC of distributed batteries in DC microgrids[J]. in IET Generation, Transmission & Distribution, 2019, 13(20): 4667-4676. [11] Shehata E G, Thomas J, Mostafa R M, et al.An improved droop control for a low voltage DC microgrid operation[J]. 2018 Twentieth International Middle East Power Systems Conference (MEPCON), Cairo, Egypt, 2018: 850-855.
2020, Vol. 21 
