Based On Dsp Of Electric Lift Trucks In The Controller Design And Implementation Of Ac Drives

Forklifts are an indispensable part of modern logistics field. With the further development of society, environment protection and energy saving are emphasized and electric forklifts are becoming increasingly preferable. Due to the advantages of easy-maintainability, good speed-regulation, high-reliability, electric forklifts based on AC motor drive mechanism gain high attention and become a major tendency of forklifts. Currently, foreign companies have accumulated rich experience in designing the driving controller and manufactured their own mature products. Nevertheless, domestic driving controllers are mostly imported due to lagging in technology. Thus, more efforts and further research are in badly needs. In this paper, a new design of AC electric forklift which is based on TMS320F2812as the master chip and MOSFET as the converter was presented.The structure of PMSM applied by electric forklifts and the relevant mathematical model was firstly introduced theoretically. Then the theory of vector-control is analyzed and the principle of SVPWM was deduced. The PID digital algorithm referred in the paper was briefly introduced. On the hardware side, the control board, drive board and inverter were designed basing on the analysis of the controller’s overall functions. The functions of each circuit board and the role of main circuit modules were elaborated in detailed. Further, radiator was designed according to the practical conditions. Programs for main control, fault handling, protecting, parameters setting and monitor were written based on Modularization, and the core module was illustrated from theory and workflow as well. After the test of the driving controller with or without load under open-loop and closed-loop, experiment results showed the driving controller is of good speed-regulation and all parameters can satisfy the walking demand of the electric forklift.