DC magnetic properties of soft magnetic materials, the ripple effects of measurement
|School||Xi'an University of Technology|
|Course||Precision instruments and machinery|
|Keywords||Soft magnetic materials Ripple voltage Switching Power Supply Flyback converter Magnetic induction|
DC power supply is a soft magnetic material in the magnetic properties of the measurement system an important part of the conventional magnetic power supplies are linear power supplies. With the development of power technology, at present, switching power supply in many areas of its light weight, small size, high efficiency, low power consumption rapidly replacing the linear power for most electronic devices for energy supply. However, the relatively linear power supply, switching power supply has an obvious drawback is that the output ripple voltage and high. If you do magnetization switching power supply, this disadvantage will definitely affect the measurement results, resulting in a measurement error. In this paper, the national standard GB3657-83 DC magnetic properties of soft magnetic materials, methods of measurement as a platform, first of all, through the process of magnetization of soft magnetic materials and related experiments, analyzed the ripple of the DC magnetic properties measurements. Secondly, switching power supply input stage rectification process, analyzes the generation of low frequency ripple and switching power supply according to the macro model, using power matching method and the equivalent current source method derived switching power low frequency ripple voltage is calculated; against flyback transformer of energy transfer process, analyzes the mechanism of the switching frequency ripple and inductor flyback converter based on complete energy supply mode (CISM), not entirely inductive energy supply and continuous current mode (Ⅱ SM-CCM), not completely and discontinuous inductor current mode for energy (Ⅱ SM-DCM) three operating modes, for the corresponding ripple calculation; for switching power supply ripple voltage measurements, introduces several industry-recognized oscilloscope measurements. Then, and flyback switching power supply for low-frequency ripple and switching frequency ripple, design the corresponding ripple attenuation circuitry, including the LC resonant filter and LDO circuits, and conducted Pspice simulation results show that the ripple attenuation effect is obvious. Finally, the DC magnetic properties of soft magnetic materials measurement system requires a constant magnetizing current to provide a constant magnetic field on the characteristics of the steady flow to eliminate the switching point of the DC power supply ripple measurement of magnetic properties, was designed for providing a constant magnetization a constant current magnetic power. Experiments show that the application of the switching power supply ripple attenuation measured magnetization relative error is less than ± 3%, meet the national standard requirements. The research work for the switching power supply in the magnetic characteristic measurement application provides a certain reference value.