The synchronous wind turbine with hydraulic torque converter is a kind of frontend adjusting speed wind turbine based on the coupling of hydraulic torque converter and brushless synchronous generator. The key technology is to adopt the frontend adjusting speed technology to keep the generator speed constant and realize synchronous grid connection. The fuzzy closedloop control of speed is applied on the lowspeed drive chain of the wind turbine, and the control of torque balance is executed by the hydraulic torque converter technology on the highspeed drive chain. The dynamic response speed and accuracy of the speed and torque control is greatly improved when the wind turbine undergoes the lowvoltage ride through. Simultaneously, the forced excitation mode of excitation system introduced in synchronous generator can increase the generator EMF rapidly, compensate the loss of electromagnetic power timely, and provide reactive energy support for the power grid to maintain the stability of the power grid. The certification test of low voltage ride through performance for this wind turbine is executed on site. The result demonstrates the effectiveness and feasibility of this control strategy.