Flow distribution control method, device and system in lifting process of drill bar of rotary drilling rig

The invention discloses a flow distribution control method, device and system in the lifting process of a drill bar of a rotary drilling rig. The method comprises the following steps that the actual rotating speed of a power head system is obtained; the actual rotating speed of the power head system is compared with the expected rotating speed, and the rotating speed deviation e and the deviation change rate ec are obtained; inputting the deviation e and the deviation change rate ec into a fuzzy controller to obtain proportionality coefficient variations delta Kp, delta Ki and delta Kd; inputting the proportionality coefficient variations delta Kp, delta Ki and delta Kd into a PID (Proportion Integration Differentiation) controller to obtain a current u (t); inputting the current u (t) to a proportional amplifier to obtain an amplified current value; based on the amplified current value, the opening degree of the valve port is adjusted, the rotating speed of the power head system is kept stable and constant u