A power allocation method for grid-connected MMC inverter based on droop control

摘要

Droop control has been widely used for controlling distributed generators. As capacity of the MMC inverter may be insufficient, a power allocation method for grid-connected MMC inverter based on droop control is presented to improve the stability of the power system. As there is potential for large disturbances in the power grid, an equal speed regulation strategy is adopted to make the speed of the voltage collapse be the same as the frequency collapse. With obtaining the active and reactive power references of MMC inverter according to equal speed regulation strategy, the deadbeat control method is calculated using these power references and adopted to track the reference currents. The Routh criterion is used to analyze the influence of the inductance measurement error on the control system. Additionally, a simulation model is established with Matlab and Simulink. The simulation results show that the stability of the power grid has been improved with the proposed control method.