Abstract：The permanent magnet synchronous generator（PMSG）is prone to current overstep in unbalanced

grid，which affects the reliability of grid-connected system. To solve this problem，low-voltage ride-throgh control

strategy based on direct power control was proposed. In this strategy，the direct power inner loop was used to

control the grid-side inverter，and the active power and reactive power instructions were divided into DC

components and double frequency AC components. The reference values of the DC components of active power

and reactive power were calculated on the premise of the low voltage traverse reactive power support and the

current amplitude of the inverter. The reference values of the AC components of active power and reactive power

were calculated according to three different control objectives according to the voltage and current of the junction

point. Then the control loop was designed by the quasi-proportional resonant controller. Finally，a simulation model

was built based on Matlab/Simulink，and the simulation results show that the proposed control strategy can improve the dynamic performance of the inverter and improve the operation ability of the grid-connected system under the unbalanced grid.

      Key words：permanent magnet synchronous generator（PMSG）；unbalanced grid；low-voltage ride-throgh

（LVRT）