Hydraulic yaw control method and system for wind generating set

The invention discloses a hydraulic yaw control method and system for a wind generating set. The hydraulic yaw control method comprises the steps that yaw values of the wind generating set are divided into a plurality of grades; starting, stopping and running speed curves of yaw actions of each grade are set and are in one-to-one correspondence; establishing a proportional flow valve output curve interpolation table of each divided grade; the average wind facing deviation within the time T1 and the average wind speed within the time T2 are collected in real time; and judging the size between the average wind speed of the wind generating set and the yaw starting wind speed and the size between the average wind deviation and the yaw starting wind error threshold value, and carrying out yaw wind regulation on the wind generating set in a clockwise or anticlockwise manner according to the judgment result. According to the proportional flow valve, the output flow value of the proportional flow valve can be accurat