Research on stability analysis and control optimization method of DC microgrid based on numerical simulation

Abstract

DC microgrid systems can better meet power energy demands and adapt to the future development characteristics of DC loads. Based on the structure of DC microgrids, this paper combines the operational characteristics of distributed power sources (wind power generation, solar power generation) to establish a mathematical model of the DC microgrid system. By introducing droop control into AVDCM control, fuzzy control is configured to use only the rate of change of bus voltage as input, forming an improved P-U droop coordinated AVDCM control. This establishes a control optimization model for the DC microgrid system. DC microgrid control optimization simulation experiments were conducted to explore the control optimization performance of the proposed DC microgrid control optimization model. Under grid-connected operation, both the 700V DC bus voltage and the 48V DC bus voltage can recover to a voltage-stable state within 0.1 seconds. In islanded operation, the output power of the photovoltaic panels rises to between 144 kW and 146 kW within approximately 0.7 seconds, reducing the power supply burden on the batteries. Under varying 700 V DC bus voltages, the load can operate reliably, and the 48 V DC bus voltage remains in a steady state.