The Study On Flux Observe Of Inducing Motor

Observing of stator flux is the key issue to make direct torque control into practice. DTC is selected as the way to control the motor in the article for its excellent response towards high speed of controlling. DTC is based on the control of stator flux, which must be observed accurately. The article below discusses the stator model, signal collective methods and signal processes.In order to make DTC into practice, stator signal observing and collecting must be in time. Then several typical models for the stator flux and the features are discussed, the models concludes current and voltage model, current and speed model,voltage and speed model. In the practical application, the speed and voltage model is chosen as the actual model during the control process as its ability to observe the flux in any conditions in which the motor run, especially in the low speed conditions. The model requires current, voltage and speed signals.During the process of collecting signals, we must take the speed and accuracy into consideration. In that case, PCI BUS was chosen as the method for our purpose, which meets our demands. During the process, PCI board is applied. In order to make full use of the digital collective board VC++ is applied to program so as to collect the data.The model includes the current and voltage signals which may be affected by the invertor and the motor itself. So the methods must be taken into consideration to deel with the harmonious signals, in that case we must take advantage of filters, which includes hardware filter methods and digital filter. The two different methods applied in different conditions. The former method requires circuits and the specific chip which must be designed for the special purposes. The digital filters discussed in the article consist of LMS, FIR, IIR and Kalman filter. As the Kalman filter can make sure the process of signals can be in time. So the Kalman filter is chosen applied during the tests.With the former methods, advanced improvement on motor stator flux is approached, and the signals collecting and observing are put into practice.