Research On Key Technology Of Electric Differential Bridge Crane

Bridge crane is widely used in nuclear power plants,hydropower station,chemical industry,metallurgy,heavy machinery manufacturing,shipbuilding and other places,it is a basic tool for the mechanization of material handling,carrying,lifting in the field of production and circulation,and is an indispensable equipment for the national economy.The electric differential bridge crane has fundamentally changed the traditional bridge crane from the structure type and working principle,removed the lifting mechanism on the trolley,through the electric differential drive,the driving of the lifting movement and the movement of the trolley are “combined into one”,The self-propelled trolley is changed into pull-type trolley,which reduces the self-weight of the trolley,thereby reducing the load on the main beam and greatly reducing the weight of the main beam,and realizing the weight reduction of the bridge crane.However,the multi motor and flexible traction drive mode of electric differential bridge crane will have an adverse effect on the motion accuracy of the car crane system and increase the energy consumption.So the further research is needed.In addition,the electric differential bridge crane is a new attempt,and the corresponding design and development method should be set up to promote its practical application.This article takes the electric differential bridge crane as the research object.By analyzing the principle of electric differential drive and its driving characteristics,it adopts research methods such as theory,experiment and simulation to study the energy-saving technology of multi-motor common DC bus,the kinematic and dynamic characteristics of a trolley-load system under the influence of wire rope suspension,parametric design software development and other key technologies.It lays the foundation for the practical application of electric differential bridge cranes.The main contents and innovations of this thesis are as follows:1)By analyzing the electric differential driving principle and driving characteristics of the bridge crane,it can be known that the two electric combination drives can achieve the single action or linkage action of the trolley and the load with certainty;under the single working condition of the trolley or the linked condition ofthe load and the trolley,the installed capacity of the electric differential drive is much greater than that of traditional bridge cranes,and it will lead to excessive energy consumption.However,in this operating condition,the rope-side motor is in a state of power generation and there is energy that can be used for feedback and utilization.Using appropriate energy feedback technology,the electric energy sent from the motor is transmitted to the rope-side motor in real time.2)According to the analysis result of the differential drive characteristics,the multi-motor common DC bus energy-saving technology is applied to the electric differential bridge crane,and the electric energy generated by the electric motor on the discharge side is fed back in real time to the take-up side motor to solve the problem of excessive energy consumption caused by differential drive.An electric differential drive test stand is set up to test the electrical differential drive characteristics and the multi-motor common DC bus energy saving technology.3)The kinematics model of the trolley-load system under the suspension of the wire rope is established.After analysis,it is found that the wire rope suspension had little effect on the movement speed of the trolley-load system.In order to solve the problem of fluctuations in the running speed of the trolley caused by swinging of the hoisting drum and speed difference between the drums,the PID control method is adopted and verified by the simulation test to realize the uniform motion control of the trolley.Considering the coupling effect of load swing and wire rope suspension on both sides of the trolley,based on the wire rope parabolic theory and the D’Alembert’s principle,the dynamic models of the trolley and load are established respectively,which provides the theoretical basis for the precise positioning control of the trolley-load system.4)Based on the secondary development platform of VB and APDL,the development of parametric design software for electric differential bridge cranes is completed.The method of rapid selection of standard parts based on database and multi-parameter optimization method of main beam structure based on parameter sensitivity are proposed.It is applied to the development of software and improves the use performance of software.Parametric design software helps to increase the design efficiency of designers and promote the practical application of electric differential bridge cranes.