Laboratory system for variable-frequency
and variable-speed motor based on virtual instrument
ABSTRACT:With the advancement of science and technology,the development of measurement technique is getting more and more important。 The application of electronic measurement technique has extended to more fields than ever。 Due to limited functions and big size, traditional electronic measurement equipment is no longer suited for common purposes。Thanks to the rapid development of integrated circuit and computer technology,measurement instruments are becoming digitized and intelligentized。 Compared with traditional equipment,the new instruments have more functions,higher processing speed,wider bandwidth,friendlier interface,smaller size and better expandability。The prevalence and rocketing development of personal on PC platform,and can make use of the software and hardware resources of a PC。Compared with its ability of data processing and flexibility,VI has a low price, which means it is a good choice for research and teaching reform in universities。
This dissertation discusses the implementation of a signal acquisition system,based on the concept of VI。With a self-developed data acquisition card connected to PC,a digital storage oscillograph (DSO)with the function of cymometer and spectrum analyzer is developed。The usage of Lab VIEW,the specialized VI softwareplatform,gives the system more flexibility and wider application。This dissertation focuses on key techniques in data transmission,display and processing。
The system which is used to measure the electric parameters of variable-frequency and variable-speed motor using virtual instrument is introduced。 The hardware and solfware are described。 The methods of increase measureing accuracy are introduced in detail 。Compared with old methods, it has many advantages, such as, flexibe application of solfware , high accuracy of measuring, simple cuicirt of hardware.
Keywords: Virtual Instrument;Data Acquisition;variable-grequency and variable-speed;alternation sampling