Analysis And Optimization Of Energy Efficiency Characteristics Of Cosed-drive Hydraulic Press With Variable Speed Pump

The hydraulic press is a machine used to compress the workpiece to cause plastic deformation.Its outstanding feature is the mass of the slider and the large load force of the work load.The large hydraulic press reaches 80,000 tons,and the gravity potential energy is wasted due to the lowering of the slider.It is quite impressive.This research is based on the "servo motor + quantitative pump" closed pump control scheme with superior energy-saving effect and simple structure.It further saves energy and optimizes the outstanding features of hydraulic presses,and proposes a dual-displacement pump motor closed-drive hydraulic press with an energy storage system Solution: Use a super capacitor energy storage system to recover the kinetic potential energy of the slider,and use a dual-displacement pump to reduce the maximum torque of the motor.The purpose of this research is mainly in two aspects.One is to study the energy efficiency characteristics of the hydraulic press,to recover the potential and kinetic energy of the slider during the idle drop stage and the hydraulic energy of the accumulator,and to supplement the busbar during the peak power stage of the workpiece pressurization.The second is to study the operating characteristics of the hydraulic press.In the idle stroke and return phase,a large displacement pump is used to speed up the operation speed of the non-working stroke and reduce the working time;in the workpiece pressurization phase,a small displacement pump is used to make the Under the same load force,the requirement for the maximum torque of the motor is greatly reduced.The general research method is to first carry out theoretical modeling of the hydraulic press and the energy storage system introduced in this research and match the parameters of each component to lay a solid theoretical foundation and provide complete and reliable data for the entire research.Secondly,in order to enable scholars in the hydraulic press field to understand the working principle of this research,the circuit design and loop control of the energy storage system are further explained in detail.Thirdly,build a hydraulic press test bench to test and study the energy efficiency characteristics of the hydraulic press during the unloading phase.Finally,use Simulation X to build a simulation model of the hydraulic press and energy storage system,and conduct a simulation study on the operating characteristics and energy efficiency characteristics of the hydraulic press.The following describes the specific content and results of this research.This article is written in five chapters:Chapter 1: Analyze the background and purpose of this research,and then the research status of comprehensive hydraulic press and energy storage system leads to the research content of this subject,and expounds the research method.Chapter 2: First divide the working cycle of the hydraulic press into three major working conditions and eight small stages,and then analyze the energy utilization of each stage and whether it is recoverable.Then the hydraulic machine's actuator,power unit and energy storage system are modeled theoretically and the parameters of each component are matched.Chapter 3: Designed the main circuit capacitance,inductance and switch tube component parameters of the bidirectional DC-DC converter according to the working conditions of the hydraulic press;then explained the charging and discharging principle and the double closed loop control method,and designed the control loop compensator In order to improve the response speed and stability;finally,the specific circuit realization of the control circuit is designed,and the principle of generating the driving signal of the main circuit switch tube is explained through simulation and experiment.Chapter 4: First,formulate energy management strategies for energy recovery and reuse in energy storage systems.Secondly,a hydraulic press test bed was built to recover energy from the idle power generation conditions,and it was proved that the energy storage system can recover 688 joules of energy within a working cycle,with a recovery efficiency of 79.3%.Finally,build a simulation model of the hydraulic press and energy storage system in Simulation X,and then through the simulation analysis of the operating characteristics of the hydraulic press,it is proved that the dual-displacement pump can greatly reduce the maximum torque of the motor,improve the efficiency of the non-working stroke,and pass the energy efficiency of the hydraulic machine.The simulation analysis of the characteristics proves that the energy storage system can improve the energy saving effect of the hydraulic press by6.9%,reduce the loss of line impedance,and reduce the power impact on the grid.