Research On Control System Of Linear Induction Motor Bi-side Driving Elevator

Linear motor is a kind of equipment for converting electrical energy into linear movement use. In most occasions where need converting rotary movement into linear movement, linear motor shows its superiority. It makes many in-between transferring machine unnecessary. Therefore, the whole system runs more steadily. In addition, thanks to the reducing of the in-between machine, the friction wastage of the whole system is reduced and the efficiency of the whole system is improved. Hence, the usage of the linear motor has a good foreground in the areas of traffic, industry, national defence and so on.With the increasing of the population and the reducing of the land, the skyscraper increase dramatically. This phenomena presents a big challenge for traditional elevator driven by rotary motor and steal wire. For this reason, the elevator driven by linear motor came into being.This paper is about the research and development of the elevator driven by linear induction motor. This type of elevator has many merits, such as simple structure, less occupied land, high speed and high layer. Some overseas companies have developed this kind of elevator and achieved great success. However, this technique is in the beginning phase in home. Professor Ye and the Taifu Electric New Technology Limited Company Attached to Zhejiang University lead the way in this area. Cooperating with Haerbin Taifu Industry Limited Company, Professor Ye and his company developed bi-side direct shoving elevator driven by linear induction motor. I am so lucky to be the member of this project, and as the primary person, I fulfilled the design of the whole control system. The work of this paper is as follows:1. Looking back the progressing history of the linear motor, introducing the features of the elevator driven by linear induction motor, radicating the topic of this paper-'the digital frequency variable control of the elevator bi-side direct driven by linear induction motor". The research of this paper covers the conventional VVVF control, space vector based VVVF control, vector control and DTC.2. Designing the whole control system for this elevator based on the space vector VVVF technique. The main chip is TMS320F240. The results are tested to verify that the control system is steady and feasible. In this control system, the distribution control theory is used.3. Aiming at the end-effect of the linear induction motor, this paper set up a simulation model and tested it, the results shows that the vector control performance is better than the conventional control for linear induction motor.4. As a new control theory for motor control, DTC has many merits. This paper constructed the mathematic model of linear induction motor for DTC control, and established the simulation model for DTC control. The results demonstrated that the DTC for LIM is feasible and simple, thanks to the control performance is independent from the parameters of the LIM.5. The usage of PMLSM in linear motor driven elevator is the trend. This paper also presents the vector control method for PMLSM. Established a control systembased on TMS320F240 and have it tested. Some results are presented. This is a foundation of further research of linear motor driven elevator.6. EMC and EMI is one of the most aspect in designing of a control system. Here, we do lots of analysis and experiments to ensure that the whole system is steady.7. Elevator control system must ensure that the passengers feel comfort when riding the elevator. However, the linear induction motor is in the state of low speed when running. So, it is more difficult to make the speed is steady and no vibration. Here we adopt some method to solve this problem.Based on these works, this paper achieved some creationary fruits as follows:1. Aiming at the end-effect of the LIM, this paper constructed the mathematic model of the LIM, and established a simulation model and have it tested, the results is the basis of the real control system.2. Developed the whole control system and achieved great success. This contro...