Dynamics of Hydraulic Transformer Controlled Motor System

The hydraulic transformer controlled motor system is the key component of the hydraulic common pressure rail system. The hydraulic transformer controlled motor system can realize energy bidirectional transmission and pressure regulatory continuously without throttling loss theoretically. Based on the working principle and the single piston kinematic model, the dynamic model of the hydraulic transformer controlled motor system is established. The pulsation characteristic of pressure is analyzed. The inherent characteristics of the system are investigated. The results indicate that the pressure pulsation has a decrease trend when the hydraulic transformer controlled angle becomes large. In the common variation ranges, the step change of the hydraulic transformer controlled angle will cause the negative response of the load pressure. And also, because of the operation condition of hydraulic transformer is easy affected by load pressure, the system stiffness is relatively low. The negative response and pulsation of the pressure cause the motor torque fluctuation. The system is not suitable for the situation with high torque control precision. The novel system structure and control method are needed.