1、PLC控制下的电梯系统外文翻译外文资料翻译Elevator System Based on PLCComposed by the order of relay control system is a realization of the first elevator control method. However, to enter the nineties, with the development of science and technology and the widespread application of computer technology, the safety of el
2、evators, reliability of the increasingly high demand on the relay control weaknesses are becoming evident. Elevator control system relays the failure rate high, greatly reduces the reliability and safety of elevators, and escalators stopped often to take with the staff about the inconvenience and fe
3、ar. And the event rather than taking the lift or squat at the end of the lift will not only cause damage to mechanical components, but also personal accident may occur. Programmable Logic Controller (PLC) is the first order logic control in accordance with the needs of developed specifically for ind
4、ustrial environment applications to operate the electronic digital computing device. Given its advantages, at present, the relay control the lift has been gradually replaced by PLC control. At the same time, AC variable frequency motor speed control technology, the way the lift drag speed has been a
5、 gradual transition from DC to AC frequency converter. Thus, PLC control technology increases VVVF Elevator modern technology has become a hot industry.1. PLC elevator control advantages (1) used in elevator control PLC, with software for automatic control of lift operation, reliability greatly incr
6、eased. (2) layer was removed and a majority of the relay, the control system structure is simple, to simplify the external circuit. (3) PLC can be a variety of complex control system, easy to add or change control functions. (4) PLC can be automated fault detection and alarm display to improve the o
7、peration of security and ease of maintenance. (5) for the group control the allocation and management, and improve the efficiency of elevator operation. (6) do not need to change the control scheme changes when the hardware connection. 2. VVVF elevator control characteristics With the power electron
8、ics, microelectronics and computer technology to control the rapid development of technology, communication technology VVVF also a very rapid rate. AC variable frequency motor speed control technology is the power to improve the process in order to improve product quality and improving the environme
9、nt and promoting technological progress as a primary means. Frequency of its excellent performance and the speed brake from a smooth performance, high efficiency, high power factor and power-saving effect of a broad scope of application and many other advantages of being at home and abroad recognize
10、d as the most promising approach speed Exchange characteristics of VVVF Elevator (1) low energy consumption (2) low load circuit, the required emergency power supply device of small In the acceleration stage, the required start-up current of less than 2.5 times the rated current. Peak starting curre
11、nt and time is short. Since the starting current is drastically reduced, so power consumption and power supply cable diameter can be reduced a lot. Required for emergency power supply devices are also relatively small size. (3) high reliability and long service life. (4) good comfort Elevator operat
12、ion is best to follow the speed curve of a given operation. Their characteristics can be adapted to human feelings, and to ensure that noise operation, smooth brake Ping layer and high precision (5) Stable noise-free (6) In the car, the engine room and adjacent areas to ensure that noise. Because th
13、eir systems use a high clock frequency. Always produce a true sine wave power supply current yet. Motor torque ripple does not appear. Therefore, to eliminate vibration and noise.3. Elevator control technology The so-called elevator control technology refers to the elevator drive system and electric
14、al control system of automatic control. 70 as the 20th century in Chinas elevator was marked by the exchange of two-speed elevator. Its speed is used to change the elevator traction motor of the very few, two or multilevel approach to the number of windings, very few of them as high-speed winding of
15、 the winding, a very few number of windings as the low-speed winding. Windings for high-speed elevator-speed start-up and running, low-speed windings for braking and the maintenance of elevators. The early 80s, VVVF inverter controlled variable lift system available. It uses AC motor drives, are abl
16、e to reach the level of DC motor, control the speed of the current has reached 6 m / sec. Its small size, light weight, high efficiency, energy saving, including the past almost all the advantages of the lift. Is the latest elevator drive system. Operation in vertical lift, there is also the startin
17、g point of the terminus station. For more than three-story elevator buildings, the starting point of the terminal stations and stops between the had not, the starting point for these stations at the first floor of the terminal located at the highest floor. Starting point in the first floor of the st
18、ation known as base stations, known as the starting point at both ends of the terminal stations and stations at both ends of intermediate stops between stations. Outside the station has a call box, box set are used by staff for elevator call button or touch the call button, the general ends of the l
19、ift stations in the call box on the Settings button or touch of a button. Middle layer of the station set up the call box button or touch button 2. No drivers for the control of elevators, at various stations are set up calls me on a button or touch button. Elevator car and the internal settings (ex
20、cept for debris elevator) to manipulate me. Control box switch on the handle or set up stations and the corresponding layer of buttons or touch-button control box on the touch-control button or command button or touch the city button. Outside the command button or touch-button issue as the signal ou
21、tside the command signal, within the command button or touch-button issue within the signal as a command signal. 80 In the mid-20th century, the touch button has been replaced by micro-button. As the elevator call box outside the base station, in addition to set up a call button or touch button, but
22、 also set a key switch in order to work the elevator clearance. Drivers or management staff to open the elevator to the base station can wriggle through a dedicated key to the key switch. Close the elevator in place to automatically cut off the elevator control power supply or power supply.4. PLC Co
23、ntrol Elevator Design With the continuous development of urban construction, the increasing high-rise buildings, elevators and life in the national economy has a broad application. Elevator high-rise buildings as a means of transport in the vertical run of daily life has been inextricably linked wit
24、h people. In fact the lift is based on external call control signals, as well as the laws of their own, such as running, and the call is random, the lift is actually a man-machine interactive control system, simple to use control or logic control order can not meet the control requirements, and ther
25、efore , elevator control system uses a random control logic. Elevator control is currently generally used in two ways, first, the use of computer as a signal control unit, the completion of the lift signal acquisition, operation and function of the set, to achieve the lift and set the automatic sche
26、duling function to run the election, drag the control from inverter to complete; the second control mode with programmable logic controller (PLC) to replace the computer control signal sets the election. From the control and performance, these two types of methods and there is no significant differe
27、nce. Most of the domestic manufacturers to choose the second approach, because the smaller scale of production, their design and manufacture of high cost of computer control devices; and PLC high reliability, convenient and flexible program design, anti-interference ability, stable and reliable oper
28、ation of the characteristics of Therefore, the elevator control system is now widely used to realize programmable controller.5. Elevator control system characteristics Operation of the lift curve is above the start to run comfort indicators lift the key features, and comfort are directly related wit
29、h the acceleration, according to control theory, for a certain amount of change according to the law must be directly controlled, for elevator control system, according to the ideal acceleration curve acceleration feedback to be used, in accordance with the motor torque equation: M-MZ = M = J (dn /
30、dt), can be seen reflected in the rate of change of acceleration of the system of dynamic torque changes on the control system to control the acceleration of the dynamic torque M = M-MZ. Therefore, during this time to control the use of the principle of acceleration, when the start rate of increase
31、in steady-state value above 90%, the acceleration control system by the switch to speed control, as in paragraph steady speed, speed control for the constant fluctuations in the smaller, little change in acceleration, speed and the use of closed-loop control can maintain a steady-state speed accurac
32、y and precision for the braking section to create the conditions ping layer. Is rising at a rate in the system, and although the above-speed PI regulator used to control, but two of the PI parameters are different in order to improve the system dynamic response indicators. The brake in the system, t
33、hat is, to reduce the speed of control necessary to ensure the comfort, but also strictly in accordance with the operation of the lift of the relationship between speed and distance control to ensure the accuracy of flat layers. To the speed in the system before 120r/min, in order to take into account both be taken
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