外文翻译--基于PLC的异步电动机运行监控系统的设计与实施.doc

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1、Design and Implementation of PLC-Based Monitoring Control System for Induction Motor ZHU Shao-ying，XU Yu，He Zheng-wen Xi an Jiaotong University，Xi an 710049，P.R.ChinaAbstract：The implementation of a monitoring and control system for the induction motor based on programmable logic controller (PLC) te

2、chnology is described. Also, the implementation of the hardware and software for speed control and protection with the results obtained from tests on induction motor performance is provided. The PLC correlates the operational parameters to the speed requested by the user and monitors the system duri

3、ng normal operation and under trip conditions. Tests of the induction motor system driven by inverter and controlled by PLC prove a higher accuracy in speed regulation as compared to a conventional control system. The efficiency of PLC control is increased at high speeds up to 95% of the synchronous

4、 speed. Thus, PLC proves themselves as a very versatile and effective tool in industrial control of electric drives.Keywords：Computer-controlled systems, computerized monitoring, electric drives, induction motors, motion control, programmable logic controllers (PLCs), variable-frequency drives, volt

5、age control.I. INTRODUCTIONSince technology for motion control of electric drives became available, the use of programmable logic controllers (PLCs) with power electronics in electric machines applications has been introduced in the manufacturing automation 1, 2. This use offers advantages such as l

6、ower voltage drop when turned on and the ability to control motors and other equipment with a virtually unity power factor 3. Many factories use PLCs in automation processes to diminish production cost and to increase quality and reliability 49. Other applications include machine tools with improved

7、 precision computerized numerical control (CNC) due to the use of PLCs 10. To obtain accurate industrial electric drive systems, it is necessary to use PLCs interfaced with power converters, personal computers, and other electric equipment 1113. Nevertheless, this makes the equipment more sophistica

8、ted, complex, and expensive 14, 15.Few papers were published concerning dc machines controlled by PLCs. They report both the implementation of the fuzzy method for speed control of a dc motor/generator set using a PLC to change the armature voltage 16, and the incorporation of an adaptive controller

9、 based on the self-tuning regulator technology into an existing industrial PLC 17. Also, other types of machines were interfaced with PLCs. Thereby, an industrial PLC was used for controlling stepper motors in a five-axis rotor position, direction and speed, reducing the number of circuit components

10、, lowering the cost, and enhancing reliability 18. For switched reluctance motors as a possible alternative to adjustable speed ac and dc drives, a single chip logic controller for controlling torque and speed uses a PLC to implement the digital logic coupled with a power controller 19. Other report

11、ed application concerns a linear induction motor for passenger elevators with a PLC achieving the control of the drive system and the data acquisition 20. To monitor power quality and identify the disturbances that disrupt production of an electric plant, two PLCs were used to determine the sensitiv

12、ity of the equipment 21. II. PLC AS SYSTEM CONTROLLERA PLC is a microprocessor-based control system, designed for automation processes in industrial environments. It uses a programmable memory for the internal storage of user-orientated instructions for implementing specific functions such as arithm

13、etic, counting, logic, sequencing, and timing 23, 24. A PLC can be programmed to sense, activate, and control industrial equipment and, therefore, incorporates a number of I/O points, which allow electrical signals to be interfaced. Input devices and output devices of the process are connected to th

14、e PLC and the control program is entered into the PLC memory (Fig. 1).Fig. 1. Control action of a PLC. III. CONTROL SYSTEM OF INDUCTION MOTORIn Fig. 2, the block diagram of the experimental system is illustrated. The following configurations can be obtained from this setup.a) A closed-loop control s

15、ystem for constant speed operation, configured with speed feedback and load current feedback. The induction motor drives a variable load, is fed by an inverter, and the PLC controls the inverter V/f output.b) An open-loop control system for variable speed operation. The induction motor drives a vari

16、able load and is fed by an inverter in constant V/f control mode. c) The standard variable speed operation. The induction motor drives a variable load and is fed by a constant voltage-constant frequency standard three-phase supplyThe open-loop configuration b) can be obtained from the closed-loop co

17、nfiguration a) by removing the speed and load feedback. On the other hand, operation c) results if the entire control system is bypassed. IV. HARDWARE DESCRIPTIONThe control system is implemented and tested for a wound rotor induction motor, having the technical specifications given in Table I. The

18、induction motor drives a dc generator, which supplies a variable R load. The three-phase power supply is connected to a three-phase main switch and then to a three-phase thermal overload relay, which provides protection against cur- rent overloads. The relay output is connected to the rectifier, whi

19、ch rectifies the three-phase voltage and gives a dc input to the insulated gate bipolar transistor (IGBT) inverter. Its technical specifications 25 are summarized in Table II. The IGBT inverter converts the dc voltage input to three-phase voltage output, which is supplied to the stator of the induct

20、ion motor. On the other hand, the inverter is interfaced to the PLC-based controller.Fig.2 Electrical diagram of experimental system.TABLE I INDUCTION MOTOR TECHNICAL SPECIFICATIONSTABLE II INVERTER TECHNICAL SPECIFICATIONSThis controller is implemented on a PLC modular system 5, 2628. The PLC archi

21、tecture refers to its internal hardware and software. As a microprocessor-based system, the PLC system hardware is designed and built up with the following modules 2937: central processor unit (CPU) discrete output module (DOM) discrete input module (DIM) analog outputs module (AOM) analog inputs mo

22、dule (AIM) power supply.Other details of the PLC configuration are shown in Tables III and IV.A speed sensor is used for the speed feedback, a current sensor is used for the load current feedback, and a second current sensor is connected to the stator circuits 32. Thus, the two feedback loops of the

23、 closed-loop system are setup by using the load current sensor, the speed sensor, and the AIM. V. RESULTSThe system was tested during operation with varying loads including tests on induction motor speed control performance and tests for trip situations. The PLC monitors the motor operation and corr

24、elates the parameters according to the software.At the beginning, for reference purposes, the performance of induction motor supplied from a standard 380 V, 50-Hz network was measured. Then, the experimental control system was operated between no load and full load (1.0 N m) in the two different mod

25、es described in Section III:a) induction motor fed by the inverter and with PLC control;b) induction motor fed by the inverter.The range of load torque and of speed corresponds to the design of the PLC hardware and software as described in the previous sections.The speed versus torque characteristic

26、s were studied in the range 5001500 r/min and is illustrated in Fig. 7. The results show that configuration b) operates with varying speed-varying load torque characteristics for different speed setpoints . Configuration a) operates with constant-speed-varying load torque characteristics in the spee

27、d range 01400 r/min and 0100% loads. However, in the range of speeds higher than 1400 r/min and loads higher than 70%, the system operates with varying-speed-varying-load and the constant speed was not possible to be kept. Thus, for 1400 r/min both con-figurations a) and b) have a similar torque-spe

28、ed response. This fact shows that PI control for constant speed as implemented by the software with PLC is effective at speeds lower than 93% of the synchronous.Fig.6. Flowchart of cutoff/restart motor software.The efficiency for different values of was also studied. In Fig. 8, the efficiency is sho

29、wn normalized, using as base value or 1 p.u. the efficiency of the induction motor supplied from the standard network. As depicted in Fig. 8, the results show that configuration a) in all cases has a higher efficiency than configuration b). Also, at operation with loads higher than 70%, the normaliz

30、ed efficiency is 1, meaning that the obtained efficiency with PLC control is higher than the efficiency of induction motor operated from the standard 380-V, 50-Hz network without the control of PLC and without the inverter. According to this figure, the efficiency of PLC-controlled system is increas

31、ed up to 1012% compared to the standard motor operation.From a theoretical point of view, if we neglect magnetizing current, an approximate value for the efficiency iswhere s is the slip and are the stator and rotor winding resistances, respectively. As can be seen from Fig. 7, the PLC-controlled sy

32、stem a) works with very low slip values, almost zero. In all speed and load torque conditions, the configuration a) has a smaller slip than configuration b), thus the higher values of efficiency can be justified and especially at high speeds and frequencies. At lower frequencies, the magnetic flux i

33、ncreases and, thus, there is an increase in magnetizing current resulting in increased losses.This system presents a similar dynamic response as the closed-loop system with V/f speed control. Its transient performance is limited due to oscillations on torque 32 and this behavior restricts the applic

34、ation of this system to processes that only require slow speed variation.Fig.8 Efficiency of controlled system with and without PLC per unit of efficiency of standard supplied motor.Fig.9 Stator voltage versus frequency characteristics of an inverter with PLC control.VII. CONCLUSIONSuccessful experi

35、mental results were obtained from the previously described scheme indicating that the PLC can be used in automated systems with an induction motor. The monitoring control system of the induction motor driven by inverter and controlled by PLC proves its high accuracy in speed regulation at constant-s

36、peed-variable-load operation.The effectiveness of the PLC-based control software is satisfactory up to 96% of the synchronous speed. The obtained efficiency by using PLC control is increased as compared to the open-loop configuration of the induction motor fed by an inverter. Specifically, at high s

37、peeds and loads, the efficiency of PLC-controlled system is increased up to 10 12% as compared to the configuration of the induction motor supplied from a standard network.Despite the simplicity of the speed control method used, this system presents: constant speed for changes in load torque; full t

38、orque available over a wider speed range; very good accuracy in closed-loop speed control scheme; higher efficiency; overload protection.Thus, the PLC proved to be a versatile and efficient control tool in industrial electric drives applications.References1 Bashore D, Oliaro G, Roney P, et al. Fusio

39、n Engineering and Design, 1999, 43:2392 zuru Yonekawa, Toshiyuka Hiromi, Hiromi Akasaka, et al. Fusion Engineering and Design, 2000, 48: 173 Raupp G, Gruber O, Mertens V, et al. Protection Strategy in the ASDEX-Upgrade Control System. Proc. 18th Symposium on Fusion Technology, Karlsruhe (D),1994. Ed

40、s. Herschbach K, Maurer W, Vetter J E, North-Holland, Publ. Amsterdam: Elsevier, 1995: 679、6824 Li Qiang. The divertor configuration properties in low-parameter discharges on HL-2A tokamak. The Proceedings of the 3rd Workshop of Chinese Academy of Sciences on Plasma Physics and Fusion Research, Heif

41、ei, China, 2004, July 3、6 word文档 可自由复制编辑基于PLC的异步电动机运行监控系统的设计与实施 朱少营，徐雨，何正文中国西安市 西安交通大学 邮编710049 摘要：本文描述了基于可编程逻辑控制器（PLC）的异步电动机监测和控制系统的实施。此外，还提出了异步电动机的速度控制的硬件和软件要求。PLC程序与用户要求的速度运行参数及对系统在正常运行和跳闸条件下的监控情况相关。变频器驱动异步电动机系统的调速，并通过PLC控制，比传统的V / f控制的调速精度更高。PLC的控制效率在同步速度高速运行时提高了95%。因此，PLC证明了其在工业电力驱动控制中可作为用途非常广泛

42、和有效的工具。关键词：计算机控制系统，计算机监控，电力驱动，异步电机，运动控制，可编程逻辑控制器（PLC），变频驱动，电压控制。一 导言随着电力驱动的运动控制技术的面世，使用电力电子技术的可编程逻辑控制器（PLC）应用已引入制造自动化制造行业12。这种应用有很多优势，如，开启时较低的压降，使电机和其他设备具有一个几乎统一的功率因数的控制能力。许多工厂在自动化流程中使用PLC，以减少生产成本，提高质量和可靠性4 - 9。其他应用还包括在使用的PLC的基础上改进电脑数控机床（数控）的精度。为了获得准确的工业电力驱动系统，需要使用带电源转换器PLC的接口，个人电脑及其他电子设备11 - 13。尽管如

43、此，这使得设备更精密，复杂，昂贵的14，15。涉及PLC控制直流电机的文章很少。这些文章涉及一些采用PLC控制电枢电压来调节直流电动机/发电机控制的速度的方法实施，及将基于自校正调节器技术的自适应控制器纳入到现有的工业PLC17。此外，其他类型的机器与PLC的连接。因此，工业PLC用于控制步进电机五轴转子位置，方向和速度，减少了电路元件数量，降低成本，提高可靠性18。由于开关磁阻电机可代替交流和直流驱动实现调速，单芯片逻辑控制器使用PLC控制转矩和速度，再加上一个电源控制器19，实现数字逻辑。作为一个可能的替代其他的一些应用涉及电梯的直线感应电机与PLC实现驱动系统的控制和数据采集20。为了监

44、测电能质量和识别破坏电能生产的干扰，需要两个PLC来确定设备的灵敏度。二 PLC作为系统控制器一个PLC是一种基于微处理器的控制系统，用于在工业环境中的自动化进程控制。它使用一个可编程的存储器，用户至上的指示执行特定功能，如算术内部存储，计算，逻辑，顺序，时机23，24。PLC可编程来进行感应，动作和控制工业设备，因此，采用的I / O点，允许电信号接口。输入设备和输出设备连接到PLC的控制程序输入到PLC内存（图1）。在我们的应用程序中，它通过模拟和数字输入和输出控制不同的恒定负载的异步电动机的运行速度。此外，PLC根据控制程序连续监测输入和激活输出。这是特定的硬件模块，直接插入一个专有总线

45、：中央处理器单元（CPU），电源PLC控制程序输入输出图1 PLC的控制动作供应器，输入输出模块I / O，程序终端组成的组合式PLC系统。这种模块化的方法，可以扩大将来的扩展，如多机系统或计算机的连接。三 异步电机控制系统实验系统框图如图2所示。系统配置可由下列步骤进行。a）恒定转速的闭环控制系统，由速度反馈和负载电流反馈系统构成。感应电机驱动变量的负载，信号由变频器送入，PLC控制变频器的V / f输出。b）一个开环变速操作控制系统。异步电机驱动变量负载。c）标准变速操作。异步电动机驱动变量负载，接收恒定的电压恒定频率标准的三相供电的反馈信号四 硬件描述该绕线式异步电机实施和测试控制系统的

46、技术规格在表一给出。异步电动机驱动直流发电机，它提供了一个变量负载R。三相电源连接到主三相开关，然后是三相热过载继电器，它提供了对电流过载的保护。继继电器输出连接到整流器，来矫正三相电压，并给绝缘栅双极晶体管（IGBT）变频器一个直流输入。其技术规范25总结在表二。 IGBT变频器将直流电压转换为三相电压输出，提供给异步电动机的定子。另一方面，变频器连接到PLC控制器。表一 异步电动机技术规格接线类型输入电压380/660V ac输入电流1.5/0.9A额定功率0.6KW输入频率50Hz极数4额定转速1400rpm这种控制器由PLC的模块化系统实施。 PLC的体系结构是指其内部的硬件和软件。作

47、为一个基于微处理器的系统，PLC系统的硬件设计和建造以下模块29 - 37：中央处理器（CPU），离散输出模块（DOM）离散输入模块（点心）模拟量输出模块（AOM）的模拟输入模块（AIM）电源。PLC配置的其他详情载于表三和四。图2 实验系统的电气原理图速度传感器用于速度反馈，电流传感器，电流传感器用于负载电流反馈，第二个电流传感器连接到定子电路32。因此，两个闭环系统反馈回路是由负载电流传感器，速度传感器，和AIM安装而成。 测速器（永磁直流电动机）用于速度感应。感应电机驱动机械轴和产生输出电压，其中电压的大小与旋转速度成正比。极性取决于旋转方向。测速发电机的电压信号，必须与AIM指定的电压范围（0-5伏直流和200 - 内部阻力）符合。其他PLC外部控制电路的设计，使用24 V DC电源的低电压。五 结论系统在可变负载运行过程中进行了测试，包括对异步电动机的速度控制性能的测试和行程的情况下测试。 PLC根据软件监控电机运行和相关参数。开始时，为异步电动机性能测试提供一个标准的380伏，50赫兹网络。然后，实验控制系统在空载和满负荷（1.0 N m）两种情况下测试。a）由变频器和PLC控制的感应电机的反馈;b）变频器控制感应电机的反馈对应PLC硬件和软件设计的负载