| Forklift using accumulator as power has become a mechanical equipment which has been applied in many aspects at present. It owns many benefits: Zero-pollution emissions, the high level of energy conversion, the low level of noise etc. At present,the capacity of accumulator is an important factor to limit the working time of Forklift now. The Forklift owns high level of working frequency, recycling the power of recovered energy is an important method to prolong the Forklift working time.In this paper, the Super capacitor is selected as the energy storage because of its charging/discharging and efficiency character, the DC/DC convertor has been applied to improve the efficiency and charging/discharging problem for the volt changing. Firstly, the super-capacitor connect with DC/DC convertor as a whole,then this part connect with accumulator in parallel style as the energy system for the Forklift, so the advantages for the accumulator and super-capacity can be used respectively and dynamitic performances can be improved, finally Forklifts and accumulators can obtain more working time.HELI CPD30F2 Forklift which can carry 3T at large was selected as research object in this paper. By analyzing its working conditions, the technical route is applied as following: Firstly, the kinematics characteristics and a recycling the potential energy scheme has been analyzed by using a new type of steel wire rope hosting system in references 22, the goods descent with constant speed to make sure lower volt change of generator output. Secondly, during recycling the braking energy process, there are some problems such as the output volt of generator has been reduced during the braking process and voltage of super-capacitor during the discharging process is rising. In order to solve the super-capacities volt changing problem during the charging/discharging process, DC/DC convertor was applied to adjust super-capacities; By adding the PID controller to realize the constant electric current during the charging process. Finally, the super-capacities, which normal voltage is 48 voltage and total capacity is 667 F, is selected as energy recyclingdevice. The result of recycling system has been discussed by comparing the results which is obtained by simulation experiments using MATLAB/Simulink software.Finally, there are a few types of working conditions for theoretical calculation to confirm the rationality and economical efficiency of these devices.The results have showed that demands for goods steady decline and deceleration braking has been satisfied using regenerative braking, and it can realize the recycling the renewable energy by the way. The recycling efficiency by theoretical calculation is 58.5%, the real efficiency by the method mentioned upon is 54.2%,this could prolong the working time for 3.57%. The error between simulation and calculation is 7%, it belongs to the normal range, we can conclude that this recycling system is reasonable from these results. The recycling efficiency for braking-process is higher than cargo descending process by comparing these results. |
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