Research On The Alternating Magnetic Field Generator Based On DSP

Biomagnetism, studying the interplay between magnetic field and features and the life law of living things, is an interdisciplinary course. Nowadays, Biomagnetism has been widely used in many fields, especially in the fields of medicine, agronomy and biological engineering research. For example, in the field of medicine, electromagnetic heating is used in hyperthermia therapy, which has effect and no side effects; in agronomy, the research on biology breeding is numerous, mainly studying seeds of growth rate, resistance and output and to observe weather the growth of seed is in line with our expectation. in biological engineering, the research on the cardiovascular and endocrine disease effects of low frequency magnetic field is abundant up to the molecular and gene level.In recent years, offshore wind power plant has been developed on a large scale, so marine environment will be impacted by magnetic field because of the current of submarine cable. An alternating magnetic field generator is designed in order to effects of low frequency magnetic field on fish fries (with the limits of5cm) in this paper, and the alternating magnetic field generator is made of variable-frequency power sources and magnetic circuit, besides, that variable-frequency power sources excites coils of magnetic circuit can produce controllable magnetic field. The control of magnetic circuit applies series resonance of RLC, increasing output efficiency of magnetic field. The magnetic field is produced in the gas of magnetic circuit, the magnetic field of which varies with frequency and amplitude of the current of coils. The adjustable range of magnetic field intensity is from0.1mT to1mT, and the adjustable range of frequency is from20Hz to400Hz.The design solutions of alternating magnetic field generator are proposed, and structure of a system and operational principle are introduced, drawing lessons from induction heating power supply in this paper. Besides, series resonance of RLC proposed and designed by analyzing operational principle and the calculation methods of magnetic circuit. In addition, single-polar SPWM of double frequency control algorithm and improved incremental PID algorithm of intelligent integration are detailed in this paper. Aiming at design plan of system, hardware circuit and software of system are introduced at length respectively. And hardware circuit of system contains APFC circuit, the full bridge inverter circuit, control circuits and so on. At the software, design solutions and implementation procedure are dealt with more fully.Finally, it tests the out frequency of system and gains the current waveforms of coils in the magnetic circuit. When current of coils varies, magnetic field intensity of gas will change. The alternating magnetic field generator can work steadily by tested and improved many times.