Output Speed Control Of Hydraulic Generators On Running Vehicle

Due to small size and large power and low noise, vehicle hydraulic generators have super advantages in the field of military, industrial, agriculture, compared to traditional generators. According to hydraulic motor output speed fluctuation, when driving, this paper set the variable pump motor speed control system as the research object and motor output speed control has researched under engine speed and load change.A variable displacement pump, a fixed motor and an alternate current synchronous generator were chosen according to technical requirement. The structure and working principle of variable displacement pump was researched and the adjusting mechanism mathematical model of variable displacement pump was constructed. Based on the relationship between pump and motor, pump control motor system mathematical model was established. At last the pump control motor system was analyzed.The traffic simulation model, the variable pump motor speed control system simulation model and equivalent generator simulation model were established under AMESim software condition. The system was simulated with PID control and the motor output speed was received. The simulation results show that the motor output speed curve appeared overshoot and shock under start stage, large rotation speed fluctuation, speed down under sudden load. System has low stability and low control precision.Aiming at output speed overshoot under input speed fluctuation,engine speed feed forward compensation was introduced based on engine speed signal. Aiming at motor output speed down under sudden load, the load feed forward compensation was introduced. A new control method, feed forward compensation plus speed feedback, was proposed. Based on feed forward compensation plus speed feedback control, the simulation results show that in the start stage and large rotation speed fluctuation, the input output of the motor speed curve is smooth, less overshoot; in a sudden load, the motor output speed had not appear to sudden reduced; feed forward compensation plus speed feedback can restrain motor output speed fluctuation under engine and load change, improved system control precision and stability. Its power quality satisfied the standard of military П kind of spontaneous electric power station.The test platform of vehicle hydraulic generator was established. The motor output speed control method of hydraulic generators was tested and analyzed. The experimental results show that the motor output speed overshoot quantity meet the requirements and the system pressure reach goal quickly.