Nonlinear inductor loss measuring method based on direct current bias

Abstract

The invention discloses a nonlinear inductor loss measuring method based on direct current bias, which is mainly used for solving the problem of low speed in solving the loss of a nonlinear inductance core in the prior art. The nonlinear inductor loss measuring method is realized by the following steps of: firstly, measuring the size of a measured inductor to obtain a physical parameter of the inductor; establishing an inductance model in finite element software, and carrying out grid division on the inductance model; applying voltage drive on the inductance model to ensure that a current value in the inductance model is equal to a set bias current; after the current in the inductance model reaches the bias current, applying a periodic signal to the inductance model to ensure that a current waveform in the inductance model is consistent with the actual current; and calculating the loss density of a magnetic core according to a Stienmetz equation, and finally summing to obtain the loss of the whole inductor magnetic core. The nonlinear inductor loss measuring method has the advantages of high measurement speed and high precision and can be used for circuit design.

Description

technical field [0001] The invention relates to a loss measurement method, in particular to the iron loss measurement in the magnetic element, which can be used for the measurement of nonlinear inductance loss under the condition of direct current bias. Background technique [0002] Due to the particularity of iron loss measurement in magnetic components, the estimation of iron loss under different working conditions has always been one of the problems that plague the academic and industrial circles. In recent decades, the finite element method has been adopted by a large number of engineers and researchers: Basak has developed a software for analyzing the magnetic field distribution and loss distribution of the three-phase three-arm transformer core by using the finite element method; Ansys and Ansoft The company also launched an embedded core loss measurement module software based on the finite element method. However, many problems are still encountered when measuring th...

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Problems solved by technology

However, many problems are still encountered when measuring the loss of the inductor core. The reasons are as follows: First, because the inductor core is always used in a large DC bias environment under normal working conditions, and Under the influence of these DC biases, the loss will be very different. Therefore, the analysis of the iron loss problem of the inductor needs to be carried out when the average current of the inductor and the volt-second value of the voltage on the inductor are both steady-state, and the common finite element It takes a long time for the software to reach a steady state, which leads to a long solution process; secondly, the partial saturation of the inductor is relatively common in actual production, such as magnetically saturated inductors, transient peak absorbing inductors, LTCC inductors, etc. There will always be saturation in the work, and according to the Stienmetz formula, the loss is related to the amplitude ΔB of the magnetic induction intensity. When the loss needs to be measured accurately, the grid must be divided according to the gradient relationship of the iron loss density. Otherwise, the There will be a large error; finally, due to the saturation phenomenon of the inductor, the current waveform is not a triangular wave. How to determine the starting point of the applied voltage excitation to ensure that the current response after the application is consistent with the current waveform of the steady-state operation becomes a reliable way to obtain a The key to ΔB within the cycle

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