Research Of Core Loss Measurement Of High-frequency Magnetic Components

Magnetic component is an important part and an important influence factor of high power density and high efficiency of the power converter. The core loss is an important basis for magnetic components selected. Accurate core loss data is particularly important for designers. So the research on measurement methods of the core loss is of great significance.This paper describes the existing measurement method of core loss, and analyzes the characteristics and shortcomings of each method, and indicates that DC measurement can avoid the impact of measurement error with the deviation of the phase angle of voltage and current by traditional AC power meter as measuring magnetic components of high impedance angle. A prototype based on DC measurement is designed to measurement the core loss with the rectangular wave, etc. excitation, it converts the DC input into the waveform excitation that is applied to the magnetic component by DC/AC full-bridge inverter circuit,then measures the input DC power and obtains the core loss value indirectly. In this paper, DSP control bases on TMS320F28022 is adopted, it can generate multiple PWM easily, and adjust the dead time. The hardware circuits and the loss composition of the equipment are analyzed in detail. The calibration method of deduction circuit losses is described. In order to set the desired parameters and read the status data in real-time, an upper computer interface with functions and operations is designed. It will take long period calibrating the circuit losses by hand, and the operation is also complicated, therefore the automatic calibration interface is also designed in this article, it can measure in real-time and save data by setting the relevant parameters.The calibration of the prototype uses three air core inductors, and the formula of circuit losses is obtained. we verify for accuracy with the other two air core inductor. To verify the measurement accuracy of the prototype for measuring the magnetic component losses, the paper compares the measurement results of the prototype and the calorimetric method. The device based on the calorimetric method device and the calibration is described. Experimental results show that the error is less than 10%.Finite element simulation is with reference value in core loss model research. This paper analyzes the principle of core loss simulation of Ansoft Maxwell, and uses Mathcad to compile a model formula. It is shown that the calculating results are consistent with the Ansoft simulation results. The core loss of a particular core is simulated and experimented, and the measurement results were analyzed.