Research on a new improved droop control method for DC microgrid
Xu Hongjian1, Zhao Tao2, Zhu Aihua1, Ji Ningyi1
1. School of Electric Engineering, Nanjing Institute of Technology, Nanjing 211167; 2. School of Automation, Nanjing Institute of Technology, Nanjing 211167
Abstract In the DC microgrid, droop control is one of the basic control methods to solve the problem of load power distribution in multi-micro source systems. The traditional droop control strategy is the U-I droop control which is based on fixed droop coefficient. Although this method has good reliability and economy, the output power of each micro-source to the load can’t be allocated reasonably because the line impedance of each micro-source to the load end is not identical. Therefore, an improved droop control method based on voltage offset compensation control and current distribution compensation control is proposed. The average value of output voltage and current of each converter is used to correct the output voltage and current of each converter in this method, so as to reduce bus voltage drop and improve the accuracy of current distribution of the converter. The control method is verified by simulation under the conditions of inconsistent line impedance and common load fluctuation respectively, and the results verify the effectiveness of the control strategy.
2019, Vol. 20 
