| The well adaptability,firmness and flexible mobility of the large loader in open-pit mining operations make it an indispensable shovel and mining equipment in the mining process,but at present the large loader is mainly driven by hydromechanical transmission.The large loader with this transmission mode has some problems such as serious power loss,poor fuel economy and high noise when operating under heavy load conditions such as traction shoveling loading.Aiming at the above problems,this paper takes the large electric drive wheel loader as the research object,and carried out theoretical analysis and simulation research on the performance parameters matching method and control strategy of it.Firstly,this paper analyzed the operating process and the characteristics of each operating stage of the wheel loader under its typical cycle conditions,and based on this,the type of electric energy conversion and the selection of main components in electric-drive system of the large electric drive loader were determined,in addition,the principle of the electric-drive syestem was expounded in detail.After that,the dynamics of the large loader and its traction resistance under different operating conditions were analyzed,and the traction resistance under each driving condition was expressed through specific expressions.Then,the theoretical matching between engine and generator,diesel generator and traction motor was completed from the perspective of working characteristics of engine and generator,at the same time,the calculation method of the performance parameters of the main components in the electric-drive system was given.Secondly,the key transmission devices of hydromechanical transmission and electric transmission were analyzed and compared,based on this,the feasibility and superiority of electric-drive system as the transmission system of the large loader were demonstrated,and the control method of the large electric drive loader was studied.Under the premise of ensuring the power performance of the large electric drive loader,two schemes of engine full power matching and partial power matching electric-drive system were proposed,so that the loader can maintain constant power output under different operating conditions,and the respective control objective of the two schemes was realized based on PID control.Finally,the simulation model of the large electric drive loader was built in the AMESim simulation software,the rationality of the performance parameters matching method of the large electric drive loader was verified,and the operating performance of the large electric drive loader under the two power matching schemes was simulated respectively.The simulation results show that the performance parameter matching method proposed in this paper is reasonable,and the large electric drive loader with the two power matching schemes can achieve constant power traction under different operating conditions,as the full power matching scheme is adopted,the large electric drive loader has better power performance and similar fuel consumption than partial power matching scheme,the specific performance is as follows: the working efficiency of the large electric drive loader with full power matching is 23.5% and18.7% higher than that of the partial power matching method under the traction shovel loading condition and transportation condition respectively,the fuel consumption rate under the two operating conditions is higher than that of the partial power matching method by 4.6% and 13.9%respectively,and at the acceleration stage between the finish of bucket lifting and stable transport,the loader gains 15.4% more impetus than that of the partial power matching method. |
PDF Full Text Request