Abstract:A mathematical equation system was derived based on the Lagrange method for wind vane electric double inertia vibrator fatigue loading system, and thus a electromechanical coupling equation of the system was built. Using the small parameter cycle average method, the approximate analytic system vibration was derived for coupling process synchronization stability conditions. The influencing factors on the motor load torque in the process of system operation were obtained, and the mechanism of system coupling was revealed. On this basis, a simulation model was established to numerically simulate system frequency characteristic, and the vibration characteristics of blade under different loading frequencies were obtained. Experimental study on system frequency characteristics, main resonance electromechanical coupling characteristics, and control synchronization verifies the correctness of the mathematical model and simulation model and the feasibility of the control, providing reference for engineering application of fatigue loading system and test.