Abstract: In order to avoid an off-grid accident of a direct-drive permanent magnet wind turbine during asymmetrical grid faults, when the grid voltage drops asymmetrically, the mechanism of the DC link capacitor voltage swell caused by the unbalanced energy of the generator side and the grid side is analyzed. A coordinated control strategy of parallel super capacitor energy storage and sequence component is proposed. Some factors are considered such as the voltage drop degree of the power grid during asymmetrical faults, the energy storage limit of the drive system, and the constraints of the converter. Through the double closed-loop control of the generator and the grid side converters, the active power of the busbar can be quickly balanced, and reactive power can be compensated to improve the grid voltage. The capacity of the capacitor is selected according to the life of the super capacitor and other influencing factors, and the DC-DC converter is used to control the energy storage mode of the super capacitor to limit the voltage of the DC link supporting capacitor in the fault phase. The simulation results show the effectiveness of the control strategy and improve the asymmetric fault ride-through capability and operational stability of the direct-drive permanent magnet wind power system.