Low-voltage ride-through control method for hydraulic wind generating set

The invention relates to a low-voltage ride-through control method for a hydraulic wind generating set. When the voltage of a power grid drops, a rotating controller realizes variable-displacement-motor tilt angle control so as to make high-voltage pressure of a hydraulic system drop rapidly so that the rotation speed of a metering pump is increased and thus remaining power is stored in a wind wheel. When energy storage quantity of the wind wheel reaches a set value, a power controller controls opening of a proportional throttle valve and converts redundant energy of the system into heat energy. Controllable variants in the system include control signals of the proportional throttle valve and control signals of a swash-plate tilt angle of the variable displacement motor. The low-voltage ride-through control method for the hydraulic wind generating set adopts a double-variant control strategy and a control system has two controlled variants which are controlled in a coordinated manner; a coordinated control method for the two controlled variants and an energy distribution scheme are proposed; a proportional throttle unit is added so as to speed up responses of the whole system; and at the same time, the system has more than one controllable parameter so that control is more flexible.