Applied Mechanics and Materials Online: 2013-09-11 ISSN: 1662-7482, Vol. 421, pp 601-604 doi:10.4028/www.scientific.net/amm.421.601 2013 Trans Tech Publications, Switzerland Research and Design on Electric Control System of Elevator Tower for Safety Devices Yuan Xiao 1, a, Jianping Ye 2,b, Lijun E 1, Ruomeng Chen 1 1 China Special Equipment Inspection and Research Institute, Beijing, China 2 Wuhan Polytechnic University, Wuhan, China a xyduong@163.com, b pjycn@sina.com Keywords: Electric control system; Elevator tower; PLC; Inverter Abstract. According to the test requirements of elevator safety devices, the electric control system of elevator tower was designed and developed. The control system was divided into four layers: management layer, control layer, driving layer and execution layer. The Siemens S7-300 was used as the logic controller. The inverter VS-616G5 was used as the driving component. To implement close loop control, the PG card was used to receive the feedback signals send by encoder. Three software modules were developed and each module is corresponding to the kind of test. Introduction With the rapid development of economic and improvement of requirements for material life, the elevators are widely used for high-rise and super-high-rise buildings. As the absolutely necessary transport tool for high-rise building, the elevators become indispensable for daily life [1-3]. To protect the life and property,the most important is the reliability and safety of elevators. Therefore, special safety devices are used to improve the safety and reliability of elevators. The common used devices are rope brake, double action safety gear, elevator governor and so on [4-5]. The performance and reliability of safety device are to be checked before type registration. At present, the tests are operated on simple simulation experiment apparatus [6-7], and the results are different from that of practical working condition. Therefore, the best way is to build an elevator tower with measurement and electric control system. As the important part of elevator tower, the electric system influences the performances of elevator tower greatly. Overall design of elevator tower There are two wells of elevator tower, one is used to test the ascending protection of safety devices, and the other is used to test descending protection of safety devices and buffering mechanism. The ascending and descending frames are installed paratactic. The elevator tower is shown in Fig.1. The measurement and electric control system was divided to four layers. The top layer is management layer, the second layer is control layer, the third layer is drive layer and the forth layer is execution layer. There are three types of control method for elevator tower control system: relay logical control, PLC control and microcomputer control. The disadvantages of relay control are high fault ratio, not flexible, high loss power and so on. The microcomputer control system is powerful in intelligent control, but the anti interference performance is poor, the system design is complex, and it is difficult to maintain. The PLC control system possesses reliable running, easy maintenance and strong anti interference. Therefore, the control system of elevator tower uses the PLC control system[8]. The structure of control system is shown in Fig.2. All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans Tech Publications, www.ttp.net. (ID: 130.203.136.75, Pennsylvania State University, University Park, USA-16/05/16,22:26:14)
602 Information Technology for Manufacturing Systems IV Fig.1 Elevator tower Fig. 2 Structure of control system Design of control system hardware Overall Design of control system. The speed control system is composed of PLC and inverter. The structure of control system is shown in Fig.3. The pictures of electric control system are shown in Fig.4 and Fig.5 Fig. 3 Control system Fig.4 Driving components Fig.5 Logic controller
Applied Mechanics and Materials Vol. 421 603 The system is composed of hoist motor, traction motor, invertors, PLC, PG cards, encoders and other electric elements. The speed control system uses the high performance inverter special for elevators to drive the motors; the encoders measure the speed of motors and feedback to PLC. Therefore, the speed control system is a closed loop control system. The logical control is implemented with PLC. The PLC receives the control signal from industrial computer, operator and other position signals, sends out speed signals to inverter, release control signals and other control signals. Design of speed control system. The drive system uses the special variable-frequency motor and inverter for elevator. The variable-frequency motor controlled by inverter runs in accordance with ideal velocity curve [9]. According to the requirement of tests, the inverters control the starting, speed changing and turning of motor. The capacity of inverter was selected according to the motor, test speed and test weight. The maximum test weight is 5T, the maximum speed is 55m/min and the safety coefficient is 1.25. Then, the power of motor is: F V 5 1000 9.8 0.91 P = = 1.25 = 58.67( KW) (1) 1000η 1000 0.95 According to the required power, we selected the type of motor is YZPBF315S2-10, the rated power id 63kW. We selected VS-616G5 produced by YASKAWA. To implement close loop control, the PG card was used to receive the feedback signals sent by encoder. The wiring diagram is shown in Fig.6. Fig.6 Wiring diagram PLC. There are 20 input points and 28 output points. From the Fig.2, the PLC needs to receive the control commands from the industrial computer and send out feedback signals to industrial computer by PROFIBUS-DP. According to above requirements, we selected the Siemens S7-300 as the logic controller. Design of control software The control software was designed and developed according to the test type, running requirements and protection requirements. The elevator tower implements three types of test: ascending safety test, descending safety test and cushion test. The control logic is different from the test. Therefore, the main control software was divided into three modules based on modularization methodology. Each module is corresponding to the kind of test. The flow charts of three modules are shown in Fig. 7, Fig.8 and Fig.9.
604 Information Technology for Manufacturing Systems IV Conclusions Fig.7 Descending test Fig.8 Cushion test Fig.9 Ascending test According to the test requirements of elevator safety devices, the mechanism structure and electric control system of elevator tower were designed and developed. The test results show that the electric control system is stability and reliability. Using PLC and inverters, the development process is simple, and the electric control system is easy to expand and maintain. Acknowledgment This work was sponsored by the Technology Supported Program of General Administration of Quality Supervision, Inspection and quarantine of P.R.C. ; under contract Research on Key Technologies and Application of Elevator Tower for Safety Devices (contract number 2011QK014). References [1] G. Shen, A. So and H. L. Bai: Research Works on Super-high-speed Lifts, Elevator Word, Vol.52(2004), pp.70-76. [2] L. Jonovsky: Elevator Mechanical Design Principles and Concepts, Chichester: Ellis Harwood Ltd, 1986. [3] W.D. Zhu and L. J. Teppo: Design and analysis of a Scaled Model of a High-rise, High-speed Elevator, Journal of Sound and Vibration, Vol.264 (2003), pp707-731. [4] L. Janovsky: Elevator Mechanical Design, Chichester: Ellis Harwood Ltd, 1986. [5] D. G. Schiffner: Safety Concepts and Safety Equipment, Elevator World, Vol.38 (1990), pp23-27. [6] L. F. Guo, G. X. Zhang, Q. Gong and Q. Zhang : Application of 2-D Position Sensitive Detector in Spatial Straightness Measurement of Guide Rails, Transactions of Tianjin University, Vol.11(2005), pp44-84. [7] C. Y. Zhang, C. M. Zhu, Z. Q. Lin: Theoretical and Experiment Study on the Parametrically Excited Vibration of Mass-loaded String due to Coupling Between Vertical and Lateral Directions, Nonlinear Dynamics, Vol.37(2004), pp.1-18. [8] J. W. Sun: Based on PLC and Fuzzy Control Intelligent Control System of Elevator, Manufacturing Automation, Vol.33 (2011), pp.38-39, 49(in Chinese) [9] Y. P. Ma: Application of Variable Frequency Speed Control in Elevator System, Mechanical Research & Application, Vol.18 (2005), pp.115-116,118(in Chinese)
Information Technology for Manufacturing Systems IV 10.4028/www.scientific.net/AMM.421 Research and Design on Electric Control System of Elevator Tower for Safety Devices 10.4028/www.scientific.net/AMM.421.601