High Efficient Driving System And Analysis And Suppression Of Conducted Interference Of DC Motor In Forklift

Electric forklift as an important tool for the logistics machinery has gradually taken the place of gasoline or diesel forklift. With the rapid growth of new energy vehicles, electric forklift will enjoy greater development. Meanwhile, people set stricter requirement on performance and efficiency of motor driving control system in forklift. Now, high property motor driving control system depends mainly on import. So it's important to research DC motor driving control system with high efficiency and low electromagnetic interference(EMI). In this dissertation, build up the high frequency interference model and propose an active forward feedback EMI filter while analyze the electromagnetic interference source and propagation path in depth, then intensively and systematically analyze high frequency model and structure, parameters, performance of the filter.The efficiency of DC motor driving control system in electric forklift relates to conserve energy and it will influence operation time of forklift and service life of cell. In order to achieve high efficiency, this dissertation reduces power dissipation in two ways. On the one hand, used the synchronous continuous current technology in separately excited DC motor driving controllers to effectively reduce power dissipation. On the other hand, for power dissipation problems caused by excessive loop current when the motor is in starting process, braking, blocking and other special conditions, this dissertation proposed ant colony neural network PID tuning control strategy, which not only could reduce power dissipation but also could solve the control performance problem which is caused by parameter perturbation, nonlinearity and external disturbance, to realize that forklift is fast started and smoothly operated. Electromagnetic Compatibility(EMC) of DC motor driving control system influences the whole electric forklift reliability. For conducted EMI problems of DC motor driving control system, the first is to build up accurate high-frequency conducted interference model of this system, then propose the effective suppression measures based on this model. The current parameters of conducted interference model of motor driving control system are mostly estimated by experience which is unsuitable as the model parameters of the whole conducted interference band to be analyzed. In order to build up accurate high-frequency interference model, this dissertation presents ant colony algorithm with auto-optimization to find the model parameters on motor side and controller side. Then use PSPICE circuit simulation software to analyze the spectrum and compare the result with common mode conducted interference of line impedance stabilizing network to optimize the model. Finally, use the active forward feedback EMI filter to suppress the common mode conducted EMI.The large numbers of experiment research on performance and common mode conducted EMI of DC motor driving control system was made, and the results showed that this driving control system could effectively reduce power dissipation and improve efficiency. The structure of designed EMI filter is simple and it doesn't require any extra power supply. It could effectively suppress common mode EMI and qualify to B class regulation of international EMI.