Design And Realization Of Elevator Energy Feedback System Based On DSP

Energy shortage is becoming a serious problem, which limits social development of the new century. The question of how to increase energy utilization ratio has drawn worldwide concern. As the access interface between consumer and power network, energy feedback system can realize switchover between direct current and alternating current, which has a vast application prospect. In this paper, voltage source PWM inverter is applied to elevator control system. The voltage source PWM 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.This paper firstly analyzes the model and basic principle of elevator energy feedback system. Then, based on amplitude-phase control and vector control theory, the inverter system simulation model is built using the MATLAB simulation platform Simulink. The simulation result verifies the feasibility of control strategy in theory. Secondly, the hardware structure and design realizing method of the major loop part (including power device, drive and choke inductance) and control loop part (including sampling, votage synchronizing testing, displaying and others circuit) are further analysed. Thirdly, the major function (such as energy feedback, system protection, keystroke reading, display and communication) realizing method is investigated, and software designing implementing flow is preferred based on the above investigation. At last, the 18.5KW energy feedback device is designed by adopting amplitude-phase control strategy and votage closed loop PI regulating method. The system control theory, hardware and software function are tested based on the device.Experimentation result indicates that the system output current power factor is approximately 1 and current waveform is stable, which satisfy the system design requirement. The system can preferablely make up the defects of high energy consumption and poor stability of braking resistor of elevator control system. Before braking resistor devotion, the energy storing in frequency converter filtering capacitance is converted to alternating current and feedbacks to power network, so as to achive the purpose of saving energy, reducing consumption and stabilizing system operating.