Research on Suppression of DC Bus Voltage Fluctuation Based on Virtual Inertial Control

Multi-port intelligent power electronic equipment is a device that can connect new energy generation units such as wind and photovoltaic to power grids, loads, and other power consuming units through a DC bus, and achieve multi energy complementarity between ports by controlling energy flow. However, the input of new energy sources such as wind and solar energy accounts for a large proportion in the system, and a large number of power electronic devices are used in the system, resulting in low damping and inertia of the DC bus. Low damping and inertia cause the bus voltage to fluctuate easily due to changes in port power. To suppress the fluctuation of the DC bus voltage, a virtual inertial control applied to energy storage systems is proposed. This control method introduces the motor motion control equation into the bidirectional DC/DC converter control strategy, adds DC bus inertia, and establishes a virtual inertia control mathematical model. The influence of motion control equation parameters on system stability is analyzed and appropriate parameters are selected. Finally, simulation verification shows that the proposed control strategy can significantly improve system stability.