Feedforward compensation control in variablespeed  pump control motor system

CHAI Xiaobo1, AI Chao2, YAN Guishan2

(1. Ningbo STF Hydraulic Transmissions Co., Ltd., Ningbo 315800, China;

2. School of Mechanical Engineering, Yanshan University, Qinhuangdao 066004, China)

Abstract: Aiming at the steady speed output control of variablespeed pump control motor system, mathematical models for fixed displacement pumpvariable displacement motor of hydraulic system were established. Considering the interference in steady speed output caused by variability and randomness of variable speed input, the feedforward compensation control method was proposed. Mathematical model for this method was derived and analyzed. The transfer function block diagram of feedforward compensation control system was obtained. The variable motor swing angle was realtimely compensated according to the flow change caused by disturbance input, achieving steady speed output. Simulation and experimental research on feedforward compensation control method was proposed, based on pump motor control test platform of yanshan university. The variable speed input was achieved by variable frequency motor driving fixed displacement pump. Matlab/Simulink simulation platform was built based on the test platform. The simulation and experimental results indicate that the proposed control method has good control effect. This research lay foundation for variable speed pump control motor system in engineering applications.

Key words: pump control motor; speed control system; variable speed input; feedforward compensation