非正弦激励下高频变压器励磁参数辨识

Excitation Parameter Identification of High-frequency Transformers Under Non-sinusoidal Voltages

高频隔离DC/DC变换器是电力电子设备智能化和小型化的重要环节,其核心元件高频变压器通常工作在非正弦激励条件,励磁参数与特性均与正弦激励有较大区别。首先,该文通过解析法与保守功率理论(conservative power theory,CPT),给出非正弦激励下串联阻感参数辨识方法,通过仿真与实验验证了辨识方法的有效性。其次,在非正弦激励下对纳米晶变压器进行空载实验,提取励磁特性曲线,并对励磁参数进行辨识,分析参数变化规律。通过Simplorer/Maxwell场路联合仿真平台重现了变压器空载实验,仿真准确拟合了变压器励磁参数及其变化规律,并给出非正弦激励下磁芯磁通密度与磁芯损耗的分布,为进一步优化变压器设计提供了有效手段。

The high-frequency isolated DC/DC converter is the key to the intellectualization and miniaturization of power electronic equipment.Its core component,the high-frequency transformer,usually operates under non-sinusoidal excitation and the equivalent parameters and magnetic characteristics show deviation with those under sinusoidal voltages.In this paper,parameter identification methods of series-connected resistances and inductances under the non-sinusoidal waveform based on analytical equations and the conservative power theory(CPT)were firstly proposed.Simulations as well as experiment were carried out to verify the methods.Then no-load tests of nanocrystalline transformer were conducted to extract excitation characteristic curves and to identify excitation parameters,the changing law of the parameters was also presented with equations.Finally,a joint simulation using Simplorer and Maxwell was set to reproduce the responses of no-load tests,great agreement was seen between simulated excitation parameters with experiment results.Distribution of flux density and losses of core were also illustrated for transformer design optimization as well as DC/DC converter evaluation.