Research Of Eleator Energy Feedback System Based On Quasi-constant Frequency Hysteresis Current Control

Energy has been the focus of international concern. With the continuous development, energy consumption also increases, and energy saving will become a basic national policy in the future. In this paper, voltage source inverter is applied to elevator control system. The voltage source inverter converts the electric energy produced during elevator braking process into alternating current, whose phase is as same as power network, and responds to power network, so as to lower the system energy consumption, and it has a vast application prospect.This paper firstly analyzes the model and basic principle of elevator energy feedback system. Its mathematical model includes the stationary reference frame and the rotating coordinate system of the mathematical model. Then it gives the current feedback system for energy control technology research, introducing the indirect current control and direct current control. the indirect current control is to control the amplitude and phase mainly focusing on the direct current control techniques, including fixed switching frequency current control , small inertial current tracking control, hysteresis current control. In the hysteresis current control based on the design of the system propose the use of quasi-constant frequency current hysteresis control. Then it details 10KW renewable energy feedback system of hardware and software design. Hardware design, including the main circuit design, control loop design, human-computer interface design, the main use of formula and the hardware circuit diagram to illustrate this. Software design, the whole system of modular design, outlines the features and software for analysis of key technologies, on the basis of several important program modules: the main program, the main control program, PWM interrupt service routine , PI algorithm program description and procedures necessary process design. Finally, the design is completed 10KW elevator physical energy feedback system design, completion of the pilot, and the experimental results were analyzed.Experimental results show that the energy feedback control system power factor output current of 0.985, and the current stable sine wave export to meet system design requirements. The use of quasi-constant frequency hysteresis current control method can make the switching frequency nearly constant. So it can make the inverter output frequency fixed, the filter design is important, to better filter capacitor will be saved in the drive energy into AC back to the grid, so as to achieve energy saving,and stable system operation purposes.