Study On Computer Automatic Measure System About SST Of Silicon Stetl Sheet Magnetization Characteristic

On the support of the Natural Science Foundation of Hebei Province, this paper selected "Study on Computer Automatic Measure System about SST of Silicon Steel Sheet Magnetization Characteristic" as the subject of thesis for master's degree. It has important practical value.With the development and utilize of electric energy, the applications of soft magnetic material are more and more wide and the performance is concerned more and more by the researcher. Researching into electromagnetic field by the method of numerical calculation has had in mind, but the researcher of non-linear medium electromagnetic field numerical calculation with hysteresis characteristic is slowness. The reason is that it is difficulty to acquire the magnetization characteristic with high accuracy for non-linear medium magnetic material. In order to deeply study the electromagnetic field, first we must measure the magnetization characteristic of magnetic material with high accuracy.The measure methods have developed from the impact method to automatic-manual measure method that is central made of analog integrator and the computer automation measurement system that is central made of analog integrator, A/D> data acquisition. By now, the main measure methods of magnetization characteristic are Epstein frame method and ring specimen method, while the measure theory and measure method of Epstein frame method and ring specimen method have drawback, they can't meet the demand of high accuracy. Arm at the drawback of measure theory and measure method we have deeply studied and adopted the measure method of SST and developed double yoke iron SST.The wave of magnetic induction density will bring distortion with the raising of excitating voltage while measuring the magnetization characteristic. In order to measure magnetization characteristic with high accuracy we must keep the wave of magnetic induction is sine, so we must control the excitating voltage. On the basic of completed the wave control, we studied the accelerated arithmetic. The speed of measurement has widely improved by using the accelerated arithmetic.We adopted excitating voltage that its frequency is 0.5Hz to replace DC excitating voltage when measured the DC magnetization characteristic. Because the excitating voltage's frequency is 0.5Hz, the signal of induced voltage is very small, even though smaller than noise. So how to accurate pick the weak signal is the key of measuring DC magnetization characteristic. We solved the question by using high accuracy instrument operational amplifier and digital signal processing technique.The excitating power source also is key when measured magnetization characteristic. We developed the excitating power that applies to the SST by ourselves.With the development of computer technology electronic technology and software technology. Virtual instrument technology has been the new trend in the field of test control. In the magnetization characteristic measure system we used the virtual instrument technology. This make the measure system has friendly human-computer interface and make the measurement easier. With the virtual instrument we can upgrade the system easier.