变瓜器的运行特性 operating characteristic of transformer 损耗和效率 loss and efficiency 损話P=PLB2八G≈P-不变损耗 Pn=+12≈l=B2P--可变损耗 效率P2=U2l2coS2= 2N12N cos p cOS 2N 0+B kN 7 BSN COS,+P+B-P 变压器的效率与负载的大小、性质及铜损和铁损有关。7 变压器的运行特性 operating characteristic of transformer 损耗和效率loss and efficiency 损耗 = 2 1.3  0 − − − −不变损耗 5 0 PFe p1 Bm f G P Pcu = I 1 2 r1 + I 2 2 r2  I 1 2 rk =  2 PkN − −可变损耗 效率 2 2 2 2 2 2 2 2 2 2 cos cos  N cos N N N N S I I P =U I =U I = N kN kN S P P P P P P 2 2 0 2 0 1 2 cos 1      + + + = = − 变压器的效率与负载的大小、性质及铜损和铁损有关