The Application Research On Virtual Instrumentation Technology In AC VF Asynchronous Electric Dynamometer

The AC VF(Variable Frequency) asynchronous electric dynamometer has been widely applied to practical industry for its high-precision torque and rotor speed, excellent dynamic response and new characteristic of the energy-efficient, which is the focus of attentions in application research fields now. During the development of the AC VF asynchronous electric dynamometer, in order to thoroughly study DTC scheme of the AC VF asynchronous electric dynamometer, record and analyze actual running effect and conveniently measure active power, var, power factor, rotor speed and torque of asynchronous motor, it needs to acquire, save, analyze and display all kinds of signals of asynchronous motor. For above purpose, we must synchronously and constantly acquire several signals, such as stator voltages, stator currents, rotor speed of asynchronous motor and so on, and synchronously save, dynamically display, fully analyze and process the acquired signals. Apparently, the traditional measuring instruments can't satisfy these special requirements. If the virtual instrumentation technology which combines the computer technology and instrument technology is utilized, the above requirements can be excellently satisfied. This dissertation makes the designs and researchs on the measuring theory of voltage signals and current signals, hardware architecture, software architecture of the AC VF asynchronous electric dynamometer based on virtual instrumentation technology, and realizes the design of hardware circuit and software resolving scheme of the portion of virtual instrumentation technology based on the AC VF asynchronous electric dynamometer, according to the measuring requirements of given electrical parameters of the actual asynchronous motor. This dissertation finished the designs and factures of the virtual instrumentation hardware—the analog signal transmission circuits: the designs and simulations of data acquisition card controlled by DSP2407A, the factures and debugging of their printed circuits. Based on hardware design, it finished the designs of virtual instrumentation software architecture—user application program: the data acquisition card communication with virtual instrumentation developing environment—LabVIEW, the user application program with stable performance, easy operation and various function on LabVIEW. By means of simulative experiment, it finished the hardware debugging and software testing of the portion of virtual instrumentation technology based on the AC VF asynchronous electric dynamometer. The testing result shows that the system scheme is integral, the hardware design and software programming are right and the design requirements are satisfied.