计及谐波的J-A磁滞模型修正

J-A磁滞理论被广泛应用于电磁式电流互感器的磁特性建模,但是在谐波条件下该模型存在较大的误差。针对这一问题,文中对各次谐波分别修正经典J-A模型参数,利用遗传退火算法进行参数辨识,然后将各次谐波的磁特性进行线性叠加,实现非正弦激励下电流互感器的磁特性建模。采用该修正方法的前提是计量用电流互感器的非线性误差符合规定的0.2S级,因此对各次谐波磁滞回线的仿真分析与误差修正均近似适用于线性叠加原理。以采用纳米晶材料的0.2S级电流互感器为例,对角差与比差进行仿真分析与实验验证,结果表明经过参数修正的J-A模型改善了谐波条件下的测量准确度,多次谐波磁特性的近似线性叠加方法对测量准确度的影响可以忽略不计,从而确认计及谐波的J-A磁滞模型修正合理有效。

Modification of J-A hysteresis model considering harmonics

The J-A hysteresis theory is widely used in the modeling of the magnetic properties of electromagnetic current transformers. However,under harmonic conditions,the model has significant errors. To solve this problem,the classical J-A model parameters are modified for each harmonic,and genetic-annealing algorithm is used for parameter identification. Then,the magnetic characteristics of each harmonic are linearly added to achieve the magnetic characteristics modeling of the current transformer under non sinusoidal excitation. The premise of adopting this correction method is that the nonlinear error of the measuring current transformer meets the specified level 0.2S,so the simulation analysis and error correction of harmonic hysteresis loops are approximately applicable to the linear superposition principle. Taking 0.2S level current transformers made of nanocrystalline materials as an example,the simulation analysis and experimental verification of angle errors and ratio errors show that the J-A model after parameter correction improves measurement accuracy under harmonic conditions,and the approximate linear superposition method of multiple harmonic magnetic characteristics has a negligible impact on measurement accuracy. This confirms that the J-A hysteresis model correction considering harmonics is reasonable and effective.