Published in A R DIGITECH

Transcription

1 DC Motor Parameter Measurement and Testing By using LabVIEW KOR HARSHAL RAMESH *1, BHARATI KAJAL BALASAHEB*2, HURPADE SANTOSH NAMDEO*3 *1(B.E Student S.N.D College of Engineering Yeola) *2(B.E Student S.N.D College of Engineering Yeola) *3(Assistant Prof. at S.N.D College of Engineering Yeola) Abstract A Motor parameter measurement and testing system based on virtual instruments and microcontroller is developed. This system can sample dynamic signal including each phase voltage, speed, torque, temperature, current with very high speed and great accuracy can be achieved. For transmission serial communication is used. By using application of labview System can be graphical display performance indicators when motor is running and realize data storage and data management. It has great significance for motor research. 1. INTRODUCTION 1.1 BACKGROUND With development of technology, relationship between motor and industrial production become more and more closely, and motor control requirements are increasing gradually. So it is very important to test comprehensive performance parameters of motor. However, motor testing system based on traditional technology platform, which has been a long development period, high cost, low degree of automation, poor lack of portability and some other shortages. NI company introduced a powerful virtual instrument software LabVIEW for automatic detection and control of complex systems. It can quickly collect data, realize data analysis and processing. It achieved hardware simulation through software. Hence, a new motor detection system is proposed in this work, the whole process is organized as follow: First, we through microcontroller and related hardware to capture and conditioning motor parameters, then establishing friendly human-computer interaction system by serial protocol. At last, LabVIEW is introduced in data analyzing and processing. 1.2 LITERATURE REVIEW System identification of a dc motor is done using LABVIEW software. The transfer function of the motor can directly be determined with the help of this software. Data acquisition module (DAQ) from national instruments is a suitable module used for acquiring signals since it is compatible with the lab view. To identify the parameters of the motor, an experimental measurement of armature voltage, rotor speed is performed using NIDAQ-6008 data acquisition module. Trials are performed to apply some of the methods on the motor practically to identify the motor parameters. DAQ toolbox in LABVIEW is used to acquire the test signals. Since the transfer function is the ratio of output to input Laplace transforms with zero initial conditions, here the set of inputs and outputs can be selected as per our requirement i.e., voltage-speed, input voltage(motor)-generated voltage(generator) etc. In the present project, we considered the input as motor voltage and output as the speed of rotation. The parameters correspond to the individual terms of the transfer function. 1

2 2.HARDWARE Detection System mainly consists of DC Motor, USBCommunicationinterface,L7805CV,89S52,max232,BC 547,IN4007,LED s,7805regulator,lm324,adc0808/adc 08091N400X,lcd,AT89C51,Relay driver ULN2803,computer with labview are used. 3.SOFTWARE PC software of system is developed based on LabVIEW Features include: 1. Set motor control parameters 2. Data acquisition 3. Waveform display 4. Data analysis and management. First, computer communicates with microcontroller through USB interface, then processing real time data acquisition takes place and then use Access database for storage and finally, data in database are transferred for analysis and processing. Software is what transforms the PC and the data acquisition hardware into a complete data acquisition, analysis, and presentation tool. Without software to control or drive the hardware, the data acquisition device does not work properly DRIVER SOFTWARE: Driver software is the layer of software for easily communicating with the hardware. It forms the middle layer between the application software and the hardware. Driver software also prevents a programmer from having to do register-level programming or complicated commands to access the hardware functions APPLICATION SOFTWARE: The application layer can be either a development environment in which you build a custom application that meets specific criteria, or it can be a configuration-based program with present functionality. Application software adds analysis and presentation capabilities to driver software. To choose the right application software, evaluate the complexity of the application, the availability of configuration-based software that fits the application, and the amount of time available to develop the application. If the application is complex or there is no existing program, use a development environment. 4. USB DEVICE COMMUNICATION PROCESS One of the main instrument that is used in the project is national instrument USB It is low cost multifunction data acquisition device (DAQ) that provides the data acquisition for some applications of portable measurement. it is compatible with the lab view which is used in our project. With recent bandwidth improvements and new innovations from National Instruments, USB has evolved into a core bus of choice for measurement applications. The NI USB-6008 and USB-6009 are lowcost data acquisition (DAQ) devices with easy screw connectivity and a small form factor. With plug-and-play USB connectivity, these devices are simple enough for quick measurements but versatile enough for more complex measurement applications. DAQ software is needed in order for the DAQ hardware to work with a PC. The device driver performs low-level register writes and reads on the hardware, while exposing a standard API for developing user applications. A standard API such as COMEDI allows the same user applications to run on different operating systems, e.g. a user application that runs on Windows will also run on Linux. 2

3 5. DATA ACQUISIATION PROCESS: The complete process of data acquisition is as follows:-signal goes to signal conditioning unit 10,000-channel system LAB VIEW can help you acquire, analyze, and log data in less time. Then it gives data to data acquisition hardware and connects to computer system for accurate output. Data acquisition is to collate data transmitted from MCU and then deposited into Access database, so the Database Connectivity Toolkit is provided. MCU will send data of various performance parameters in form of an array. First we must index array in each batch to separate individual data, then get cluster binding in turns,, finally enter them into DB Tools Insert into Data VI Figure 5.1: NI LAB VIEW Graphical Programming block LabVIEW PROGRAMMING: Configuration based programming Figure 5: Data Acquisition System 5.1 INTERFACING DAC WITH labview NI LAB VIEW Graphical Programming: NI LAB VIEW is a graphical programming environment that makes it easy to take any measurement from any sensor on any bus. You can automate measurements from several devices, analyze data in parallel with acquisition, and create custom reports all in a matter of minutes with this industry standard tool. From acquiring one simple measurement to capturing data from a complex Figure 5.2: Configuration Based Programming Input Box LabVIEW distinguishes Express VIs with large blue icons. When you place an Express VI on the block diagram, a dialog appears so you can configure how the function executes. After completing the configuration, the LabVIEW development environment writes the necessary code (represented by the Express VI) for you. You can view and modify this code, and you can change theexpress VI 3

4 configuration by simply double-clicking the Express VI icon. 6. BLOCK DIAGRAM: Figure 6: Basic Block Diagram 6.1 THYRISTOR CONTROLLED DC DRIVE: Thyristor drives are very simple and were first introduced in the 1960s. A thyristor drive is a motor drive circuit where AC supply current is regulated by a thyristor phase control to provide variable voltage to a DC motor. Thyristor drive consists of two thyristors and two diodes; it converts AC supply to DC by shifting negative cycles to positive side. We can vary the output Figure 6.2: Proximity Sensor DC voltage by giving variable triggering angles to those two thyristors. Triggering to those thyristors is given using DAQ, by varying the voltage of triggering circuit using DAQ. Figure 6.1: Thyristor Control DC Drive 6.2. PROXIMITY SENSOR: A proximity sensor is a sensor able to detect the presence of nearby objects without any physical contact also various sensors are use like current sensor, Voltage sensor, Temperature sensor Speed sensor etc DC MOTOR An electric motor is a device which uses electrical energy to produce mechanical energy nearly always by the interaction of magnetic fields and current-carrying conductors. The reverse process of converting mechanical energy to produce electrical energy is accomplished by a generator or dynamo. Traction motors used in vehicles often perform both tasks. Electric motors are found in myriad uses such as industrial fans, blowers and pumps, machine tools, household appliances, power tools, and computer disk drives, among many other applications. 4

5 Electric motors may be operated by direct current from a battery in a portable device or motor vehicle, or from alternating current from a central electrical distribution grid PRINCIPLE OF OPERATION PRODUCTION OF TORQUE Consider a wire carrying a current (i) suspended in a magnetic field of uniform flux density (B), as shown in Figure, where the direction of the current is at right angles to the flux. Figure 6.3.1: Production of Torque 7. LabVIEW SOFTWARE LabVIEW is a graphical programming language that uses icons instead of lines of text to create applications. In contrast to text-based programming languages, where instructions determine program execution, LabVIEW uses dataflow programming, where the flow of data determines execution. In LabVIEW, you build a user interface with a set of tools and objects. The user interface is known as the front panel. You then add code using graphical representations of functions to control the front panel objects. The block diagram contains this code. LabVIEW programs are called virtual instruments. A VI contains the following three components: Front panel Serves as the user interface. Block diagram contains the graphical source code that defines the functionality of the VI. Icon and connector pane identifies the VI so that you can use the VI in another VI. A VI within another VI is called a subvi. A subvi corresponds to a subroutine in text-based programming languages FRONT PANEL You build the front panel with controls and indicators, which are the interactive input and output terminals of the VI, respectively. Controls are Knobs push buttons, dials, and other input devices. Indicators are graphs, LEDs, and other displays. Controls simulate instrument input devices and supply data to the block diagram of the VI. Indicators simulate instrument output devices and display data the block diagram acquires or generates. Figure7.1: Example of front panel 7.2. BLOCK DIAGRAM: After you build the front panel, you add code using graphical representations of functions to control the front panel objects. The block diagram contains this graphical 5

6 source code. Front panel objects appear as terminals on the block diagram. REFERENCES 1. LING Jing; LING Zhen-yu; ZHENG Fu-ren. LabVIEW Virtual Instrument Programming from Entry to Master [M], Posts Telecom Press, Beijing, CAI Gong-xuan. Design of MCU USB Data Acquisition System Based on LabVIEW, Experiment Science & Technology. Figure 7.2: Block Diagram for labview Programming 8. LABVIEW IMPLEMENTATION OF VISA 3.NI Tian; QIAN Zhi-bo; HUANG Chang-hua; LI Kai. A VISA is a standard I/O language for instrumentation Data Acquisition and Monitor System Based on LabVIEW programming. VISA s greatest advantage, perhaps, is that it is and Linux, Measurement & Control Technology, Test system hardware block diagram an easy language to learn and use 4 Pan Haipeng,Yao Jun,Gu Minming Zhejiang Sci-Tech University 5.IntroductionforLabVIEW[onlinehttp://en.wikipedia.org/w iki/labviw 6.DataAcquisitionSystems(DAQ)andEquipment[online]http :// acquisition.us/ Figure 8: PC program flow chart 7.labVIEW Manual. 9.CONCLUSION To establish a friendly human-machine interaction system with computer, realizes data analysis and processing by LabVIEW. Moreover, parameter measurement, data storage and management is achieved. Thus, it is valuable for motor research and has a market potential in the future. 6