Research On NEW Feeding Chopper Cascade Adjustable Speed System Based On PWM Volatge Rectifier

In the production process, Fan and pump loads are widely used. But its large electricity consumption, can not achieve an effective energy-saving effect. The traditional way to speed is speed control system which slip power is consumed, so that the output power can not changed, and increase of reactive power, waste much power. Therefore, the urgent priority is improved speed control mode of the high-capacity fan and pump loads, also in response to a national call for energy saving and emission reduction.This paper analyzes the application of traditional cascade control system limitations as well as its shorting. On this basis, proposed a new feeding chopper cascade adjustable speed system. The system consists of the feedback motor, chopper and PWM voltage rectifier. From the analysis of the mathematical model of Asynchronous Motor, Established the mathematical model of the feedback motor in the three-phase static coordinate and two-phase rotating coordinates. Search for operating principle and characteristics of the feeding chopper cascade adjustable speed system based on the traditional cascade adjustable speed system, and by comparing the efficiency of both to confirm the advantages of the latter. Research on the mathematical model of PWM voltage rectifier, analyzed its operating characteristics and the advantages which applied to the feeding chopper cascade adjustable speed system. The simulation results to determine the correctness of the mathematical model. And build up the whole model.Finally, the system is given the hardware circuit and the main software flowchart, the related experimental, through comparing the simulation results and experimental results demonstrate the chopper traps can use smooth regulating system speed; Meanwhile it also proves PWM converter applied to speed regulation system improves the power factor of system and reduce the advantage of net side harmonic content, and prevent the system from appear in their work subversion, inverter, will the rotor circuit inverter state of energy feedback to the motor stator side, the more energy, feedback the speed range, so as to achieve the purpose of energy saving.