Simulation And Experimental Study Of Energy-regenerative Electro-hydraulic Hybrid Drive Unit

In the field of heavy equipment,there are many components that operate in a rotating manner(hereinafter referred to as rotary components).The driving schemes for such rotary components are mostly driven by fuel engines and hydraulic power.However,with the increasingly prominent global environmental pollution and energy crisis,the original driving schemes no longer meet current needs.Because the motor has the advantages of zero emission,low noise,low pollution,low unit energy cost,etc.,the motor as a power source is very in line with the current needs,so the drive scheme of this type of rotary parts is also shifting towards electrification,and has been widely used.Since this type of rotary parts often have complex actions and require the power source to work in a wide power range,in order to ensure that the rotary parts can operate efficiently,the motor as a single power source in the pure motor drive scheme needs to be configured with power according to the peak load,resulting in an increase in the total installed power.During actual operation,the electric motors configured according to the scheme may experience the problem of low efficiency,resulting in a lower energy utilization rate and causing energy waste.Under deceleration and braking conditions,most of the braking energy of such rotary components is dissipated in the form of heat,which also leads to energy waste.To address the above issues,this article proposes an energy-regenerative electric-hydraulic hybrid drive unit,which mainly includes an electric motor module and a hydraulic module.Both can serve as power sources,and the hydraulic module can also serve as an energy recovery device to recover wasted energy.By matching the parameters of each module and designing the control strategies,the ultimate goal of improving the energy efficiency of the electric motor and reducing energy consumption can be achieved.The main work of this paper are as follows:Firstly,the actual operation process of the rotary parts is analyzed,combined with the problems existing in the pure electric motor drive scheme,six design principles are proposed for the new power unit,and through the structural design,the energy-regenerative electro-hydraulic hybrid drive unit(hereinafter referred to as the hybrid drive unit)is finally proposed,and its working principle is introduced in detail.Secondly,based on the hybrid drive unit,the mathematical model of the key component motor,hydraulic pump/motor and hydraulic accumulator was built,and the important parameters of the key components were obtained by studying and calculating in combination with the set parameter indicators.Based on AMESim software,the simulation model of pure electric drive scheme and hybrid drive unit drive scheme was constructed,and the correctness of the simulation models of the two drive schemes was verified.Then,based on the design principles of the hybrid drive unit,six operating modes of the hybrid drive unit were introduced,and the judgment rules for the nine control signals of the hybrid drive unit were explained.The overall control strategy for the hybrid drive unit was also formulated.An AMESim simulation model of hybrid drive unit drive scheme with the proposed control strategy was built,and the analysis of the simulation results has demonstrated the effectiveness of the control strategies proposed in this article.Finally,the impact of different parameter conditions of the accumulator and hydraulic pump/motor on the characteristics of the hybrid drive unit was analyzed through simulation,and the optimal parameters of accumulator and hydraulic pump/motor are obtained.The energy-saving characteristics of the hybrid drive unit under the optimal parameters were analyzed through simulation,and the results showed that compared with the pure electric motor drive scheme,the use of the hybrid drive unit drive scheme can reduce the peak power of the electric motor by 39.5% and reduce the energy consumption of the electric energy by38.3%,achieving a significant energy-saving effect.An electric-hydraulic hybrid power drive test bench was built to conduct experimental research on the energysaving characteristics of the hybrid drive unit under the optimal parameters.The experimental results proved the consistency between the experiment and the simulation,the experimental data can support the simulation results,and the effectiveness of the hybrid drive unit and the accuracy of the simulation model were also demonstrated.The experimental results can be approximately replaced by the simulation results.