铁磁元件铁心损耗的低频测量方法研究

Study of Core Loss Measuring Method of the Ferromagnetic Components Based on Low-Frequency Power Supply

为了变压器减小试验电源容量,使测量设备便携化,提出了一种采用低频电源代替工频电源测量铁磁元件铁心损耗的方法。该方法通过施加几个频率的低频电压测量低频下的铁损耗P_(Fe),得到不同频率的E/f(电动势/频率)-P_(Fe)曲线,再通过样条插值法计算频率不同、E/f相等时的铁损耗,根据最小二乘原理计算折算至工频下的铁损耗。并在单相变压器和电流互感器上开展试验,采用15,20,25Hz的折算的结果与工频50Hz实测结果的相对误差ε<5%,相对误差标准差σε<0.9。结果表明,本方法折算准确度高、稳定性好,而且减小了试验电源容量。

Owing to reduce capacity of testing power supply and make test equipment portable, a low-frequency power supply instead of the power-frequency power supplywhich is used for core loss measuring of ferromagnetic components, is demonstrated in this paper.By applying several low-frequencies voltage, obtained the cure of E/f-PFe（ electromotive force/frequency- core loss） viacalculating core lossin low-frequency. Core loss in low-frequency at different frequency while the same value of E/fare calculated throughspline interpolation method. Corresponding core loss in power-frequency then calculated based on least square method. In addition,investigation was conducted on the current transformer（CT） and single phase transformer, comparing conversion results which using 15,20,25Hz with directly measured results in power-frequency ,the relative error ε〈5% and standard deviation of relative error σε 〈0.9, respectively. These results show high accuracy and stability of this method. Besides,the testing power supply capacity is lower.