Modeling and Simulation of Variable Frequency Pump Control Fatigue Test Machine

High-speed maglev train is considered an ideal vehicle in the 21st Century. The travel mechanism as an important part of the train, bears and delivers a variety of vertical and horizontal alternating load in operation. It affects the operation safety of the train directly, so key components of the travel mechanism should be under fatigue strength test by fatigue test machine. The paper proposed a variable frequency pump control fatigue test machine for high-speed maglev train. It simplified the structure and improved the stability and reliability by using variable frequency pump control technology to regulate the velocity of the motion of hydraulic cylinder. Introducing the operating principle of the system, established the simulation model including frequency converter, electromotor and hydraulic system. The system performance in the cases of variable load and variable speed is analyzed with the SIMULINK of MATLAB. The system is verified correct and feasible by comparing simulation results with the actual situations. Finally, control performance of the model system was optimized by using PID closed-loop controller as well. The variable frequency pump control fatigue test machine achieved high response and high energy efficiency, so it is suitable for fatigue test application.