Design Of Iron Loss Tester Based On Embedded System

Silicon steel sheet is the essential soft magnetic material in the electric power ,electronic and military industry, which is used for manufacturing the iron cores of motors, generators and transformers. The silicon steel sheet's manufacturing technology and product quality is one of the important signs of the level of special steel's development. Silicon steel sheet in the work of the alternating magnetic field will produce iron loss(eddy current loss and hysteresis loss),whose value is one of the important quality factor of silicon steel sheet. To measure the iron loss for silicon steel sheet is a primary method to judge the quality of silicon steel sheet, which brings the producers of motors and transformers more convenience.The measure methods have developed from the Epstein frame method and ring specimen method to automatic-manual measure method that is composed mainly of analog integrator and the computer automation measurement system that is composed mainly of analog integrator,A/D,data acquisition. Epstein frame method and ring specimen method have some drawback of the measure theory and measure method, which is not convenient to use.With the progress of computer technology and semiconductor technology, the CPU of Intelligent Testing Instrument develops from 8,16-bit microcontroller(MCU) to 32-bit microcontroller(ARM),whose cost/performance ratio is constantly improving. In recent years, ARM microprocessor has been used widely by the industry control,the electronic product,the communications system and so on.Conforming to the related international standards, combining the digital and analog techniques, the paper introduces a novel Single Sheet Tester based on ARM, whose exciting power supply is sinusoidal voltage. The Single Sheet Tester can adjust automatically magnetic induction density B by negative feedback in order to keep the waveform of magnetic induction density B being a sine wave, while maintain the amplitude steady. The Single Sheet Tester can measure accurately the iron loss of silicon steel single sheet whose thickness and density is not same when the magnetic flux density is different. Besides, The Single Sheet Tester uses a probe measure method, whose measurement is easy and Non-destructive.