Design Of The Elevator Drive System Based On The Dual-PWM Control

The feedback adaptive control of PWM rectifier based on inverter output has been widelyused in AC driver system. In AC-DC-AC voltage frequency speed regulating system, dualPWM rectifier and inverter adopt PWM technology to control rectifying bridge with sine PWM,making the input current nearly approach sine wave and phase controllable. So the input currentonly contain high order harmonics related with switching frequency. These high orderharmonics can be easily filtered out while the power factor can be close to1, reducing hazardsto the power grid.As a potential type load, the elevator needed to make frequent lifting movement during theoperation process. From the point of view of the control, a renewable energy of elevator controltechnology is an important safeguard for the elevator to have a high quality running. Due to itsadvantages of high power factor,low harmonic pollution and energy reversible,Dual-PWM ACdriver system can be used in the field. This paper made a summarise with escalators and doublePWM control technology at first.Then described the PWM inverter, the basic theory of variablefrequency speed regulation and the vector control. Based on the mathematical model of thePWM rectifier under three phase steady coordinate system, the mathematical model underreference d-q is deduced by introducing the idea of rotating reference coordinate. Second，thispaper has analyzed the working principle of Voltage Source Rectifier (VSR) under steady-statecondition and come to the conclusion that the key is the control of the AC-side current. Third, itmainly described the IGBT rectifier feedback control. At last， put forward with theoperational design of inverter and rectifier with the same busbar to prove the advantage of thescheme.