三相不平衡对配电变压器效率影响数学建模与分析

Mathematical Modeling and Analysis of Effect of Three-phase Unbalance on Distribution Transformer Efficiency

为提高配电变压器效率,找到与低压配电网相匹配的三相负荷不平衡度算法,以及探究三相不平衡对配电变压器效率影响关系,选用常用的配电变压器进行分析。采用数理推导、试验建模、案例与仿真分析的方法进行推究分析,通过建立低压配电系统三相不平衡对铁损、铜损、线损影响的模型进而推导出三相不平衡对配电变压器效率的影响关系。提出了可以有效反映三相不平衡对低压配电网影响关系的三相幅值不平衡度算法、三相功率因数不平衡度算法以及三相负荷不平衡度算法,得到三相负荷不平衡对总损耗、附加损耗以及对配电变压器效率影响的关系曲线,为三相不平衡的治理和节能降损提供了参考依据。

To improve the efficiency of a distribution transformer,find a three-phase load unbalance degree algorithm which matches with the low-voltage distribution network,and explore the effect of three-phase unbalance on the distri-bution transformer efficiency,a common distribution transformer is selected for analysis.The methods of mathematical derivation,experimental modeling,case and simulation analysis are adopted,and the relationship between three-phase unbalance and distribution transformer efficiency is deduced by establishing a model of the effect of three-phase unbal-ance on iron loss,copper loss and line loss in a low-voltage distribution system.The three-phase amplitude unbalance degree algorithm,three-phase power factor unbalance degree algorithm and three-phase load unbalance degree algo-rithm are proposed,which can effectively reflect the effect of three-phase unbalance on low-voltage distribution net-work.The relationship curves of three-phase load unbalance with total loss,additional loss and distribution transformer efficiency are obtained,providing a reference for the treatment of three-phase unbalance,energy conservation and loss reduction.