Study On The Key Technology Of Energy Saving System Of Hybrid Tyre Crane

The hoisting machinery is a kind of typical construction machinery with potential energy load characteristics. A great deal of potential energy is released while the load is dropping in crane. And the crane driven by diesels also exist electric energy consumption in its idle condition. Practice has proved that less than40%of the energy is efficient during operation of the crane and more than60%is wasted as reactive power state. How to recycle and reuse the huge wasted energy of crane is the hot focus on the research of energy saving and emission reduction. Currently, energy saving solutions of crane in engineering is mainly focused on the energy storage and reuse of the renewable energy from the driving motor which is dragged by potential load. It is proved that the scheme has no fundamental breakthrough in technology due to its complex structure, low reliability and poor economic efficiency in energy conversion, storage and control. This paper takes the port tyre crane as the main object, puts forward the hybrid energy-saving system scheme based on the coaxial motor with dual armatures and variable torque, analyzes the power flow and conversion of working mechanisms with potential load, studies the architecture of hybrid driving system, establishes the control mathematical model of corresponding system, and verifies the energy-saving efficiency and reliability of the hybrid system by means of the simulation, model experiments and physical test. The main research work and innovations in the paper are as follows:1. It has established the movement and mechanical models for the tyre crane in working process of hoisting and luffing mechanisms. Then the characteristics of energy transmission, consumption and transformation in the process of ascent and decent of load have been analyzed, and the energy-saving schemes to adopt the coaxial motor with dual armatures and variable torque and recycle the energy from load potential have been proposed. Finally the methods and approach to recycle, store and reuse the energy such as potential and idle surplus energy have been studied and the construction of hybrid energy-saving system has been completed.2. It has established the function module models of the diesel engine, the separately excited DC generator, the single series DC motor, the coaxial motor with dual armatures and variable torque, and so on. It has studied the characteristics in the speed control of the coaxial motor with dual armatures and variable torque and charge-discharge dynamic control of the super capacitor, and verified the feasibility of hybrid energy-saving scheme by means of simulation about the feedback, release and control link of energy with MATLAB/SIMULINK.3. It has studied the control strategy of the energy-saving system in the hybrid crane. Based on the charge-discharge characteristics of the super capacitor, it has proposed the strategy as that constant power charge style in potential energy recovery, constant current charge style in idle energy recovery, and constant voltage discharge style in energy release. As to the performance of the coaxial motor with dual armatures and variable torque, it has put forward the speed control strategy that in energy consumption condition, the main motor is the master and the auxiliary motor regulate it, and in energy feedback condition, the main motor works idly and the auxiliary motor is adjusted with magnetic field. In view of the characteristics of potential and idle energy recovery, nonlinear dynamic excitation control and multivariable equilibrium control strategy has been proposed. And it has put forward accelerator optimization and combination of the DC generator excitation control strategy for the diesel generating set.4. Based on the working principle of the energy-saving system with coaxial motor with dual armatures and variable torque, the small power simulation experiment and single institution physical experiment research have been put to test. It has designed and developed the energy-saving system for mechanism combination industrial prototype in hybrid tyre crane. By physical prototype experiment and test, the efficiency and reliability of the system have been verified.In this paper, the achievement of the hybrid energy-saving system of crane based on the coaxial motor with dual armatures and variable torque provides a new train of thought for research on energy recycle and reuse in field of hoisting machinery. Moreover, with the implementation and further research of the study results, it will inevitably promote the crane and engineering machinery industry technical progress of energy conservation and emissions reduction.