变压器详细模型推导与三相配电潮流计算

三相变压器详细模型对于配电网分析至关重要。利用对称相量法，推导出实用的详细变压器三相模型。该模型考虑了铜损、铁损、相位偏移等问题，能够较好地分析系统三相不平衡情况。利用序分量和相分量转换的方法较好地解决了配电系统中普遍存在的因中性点不接地导致节点在相导纳阵奇异的问题。详细分析了对于辐射状和弱环网三相潮流计算方法，最终实现了可以考虑多电压等级的配电三相潮流计算程序。算例分析表明，所提出的模型和算法合理、准确，能够解决配电系统的三相不平衡潮流计算问题。

DERIVATION OF DETAILED TRANSFORMER MODELS AND THREE-PHASE POWER FLOW FOR DISTRIBUTION SYSTEM

Detailed three phase transformer models are critical for distribution system analysis. A practical model is proposed by symmetrical components based method. This model considers the copper and core losses, the winding connection, the phase shifting and off nominal tapping. A practical three phase power flow program based on the proposed model is realized. It is developed both for radial and weakly looped distribution systems of multi voltage levels. This program can also solve the problem of singularity of transformer admittance matrix. The numeral tests prove that the algorithm is practical and reasonable.