The invention relates to an
inertia synchronization PMSG self-
adaptive control method based on online impedance
estimation, and belongs to the field of
new energy grid connection. The method comprises the following steps: S1, constructing an RLS-GA
hybrid strategy
algorithm to quickly and accurately identify
power grid impedance, and determining the strength type of a
power grid; s2, establishing a direct-drive fan grid-connected
system control strategy, and adopting a
power control ring, a current control ring and an
inertia transmission control ring at a
machine side; the grid side adopts a direct-
current voltage synchronous loop, a reactive
voltage control loop and a
stabilization control loop; s3, linearizing the
control equation, and based on a linearized small
signal equation, obtaining a
state variable of the direct-
current voltage synchronous control grid-connected
system of the grid-forming type direct-driven wind
turbine generator; s4, calculating
control parameters of a reactive
voltage control loop and a direct-
current voltage synchronous loop; and S5, carrying out adaptive parameter setting on an existing permanent
magnet fan
inertia synchronization strategy so as to adapt to the change of strong and weak power grids and improve the stability performance of the PMSG under different
power grid short circuit ratios.