In order to improve the low-voltage ride-through（LVRT）capability of permanent magnet synchronous generator（PMSG）under weak grid

this paper proposes a low-voltage ride-through control strategy for power support and auxiliary protection of unloading circuits based on power grid impedance characteristics. Based on the equivalent phasor diagram of power grid

the relationship between impedance characteristics and voltage support effect is derived

and the optimal power regulation strategy is designed accordingly. When asymmetric faults are considered

positive sequence voltage is supported optimally and negative sequence voltage is suppressed optimally. Based on the proposed strategy

the low-voltage ride-through ability of the PMSG is maximized to reduce the risk of large area cutting of the power grid and ensure the reliable operation of the PMSG. Finally

a simulation model of PMSG grid-connected system is built in MATLAB/Simulink to verify the feasibility of the proposed strategy.