变压器宽频传递特性建模方法研究OA

Transformer is the key path for conducting interference in power system.For enhancing the accuracy and bandwidth of the simulation of conducted interference noise in power system,it is necessary to set up a transformer broadband transmission model.Based on the analysis of the conduction EMI characteristics of the power frequency transformer and as for the pros and cons of existing model and modelling method,the traditional low frequency model of transformer is improved and combined with the high frequency model so to set up the broadband model of trans-former.The distribution parameters are used in low-frequency part to characterize the transmission characteristics of the low-frequency noise of transformer and provide circuit equivalence to the frequency-variable eddy impedance of the winding and the core.The low-frequency variation model is set up and the physical significance of the core and winding is retained.In the high-frequency part the transformer is regarded as a black box,and the transmission char-acteristic of the high frequency noise between the transformer ports is described by the S parameters,the vector matching method is used to perform type π circuit equivalence of the admittance parameters of the port,and then the influence of the low-frequency model is corrected by subtracting the admittance so to set the high-frequency black box model with a bandwidth of 100 kHz-30 MHz.Finally,the high-frequency black box model and the low-frequency transformer model are in parallel to obtain the broad frequency tranmission model of the transformer,and the effec-tiveness of the modeling method is verified by comparing the experimental test and the simulation results.