Research On Residential Elevator Inverter System

Elevator as an important means of transport has been widely applied in the modern society. With the rapid development of the national economy, the demand of residential elevators grows much more quickly.This kind of elevators should have outstanding performance in stability and reliability. Based on extensive knowledge of the elevator drive systems,the thesis focuses on the study of the asynchronous motor inverter.The thesis analyzes the mathematical model of asynchronous motor and compares various control strategies of inverter.Slip frequency vector control technology relieves the coupling between magnetic current and torque current through effective coordinate transformation,so it can get the same control characteristics as DC motor. Chapter 3 includes simulation studies for vector control strategies and explanation for the PWM technology. Especially, the realization of SVPWM is described in detail.Chapter 4 describes the design of the system hardware, including power part and control part. Power part is made up of the main circuit,the current detection circuit and the drive&protection circuit. Control part adopts 80C196KB as the core chip and dsPIC2010 as the auxiliary chip, including the keyboard&display circuit and speed¤t detection circuit. To enhance the safety and reliability of elevators, this chapter also gives design methods of emergency power supply system to deal with the power cut accident.To avoid dependence on the electrical parameters ,the system selects current feedback tracking strategy. Based on this strategy, Chapter 5 gives the analysis of key technologies and the main software processes.The experiment has realized the current open-loop control and the current tracking control. The results show that the system has good dynamic performance and steady performance which can meet the requirements of residential elevator system.