基于平衡变压器的三相-单相对称供电条件研究及参数匹配

提出一种在平衡变压器三相变两相的基础上，根据移相原理匹配以无功补偿元件，实现三相系统对单相负荷平衡供电的三相-单相对称供电方式。该供电方式利用平衡变压器输出两相电压的正交特性，从而简化了匹配元件的计算；讨论了其三相-单相变换的拓扑结构，针对纯阻性、阻感性、阻容性3种不同性质的负荷提出了3种不同的接线方式及其匹配元件参数的计算公式；并对由匹配元件参数的误差和负荷在一定范围内变化所引起的三相侧电流负序分量增大情况进行了分析，给出了抑制此负序电流的一种解决办法；最后在一台2 kVA的平衡变压器样机上验证了所推计算方法的正确性和实用性。

Research and Parameter Analysis on Symmetric Condition of Three-phase to Single-phase Power Supply Method Based on Balance Transformer

This paper presented a kind of three-phase to single-phase symmetric power supply method, which combined three-phase to two-phase balance transformer and reactive compensation components to ensure the symmetry of three-phase currents while carrying single-phase load. The calculation of matching components is rendered in a simpler form, owning to the orthogonality of two-phase output voltages in balance transformer. The topology of three-phase to single-phase transform was discussed, and three different combinations modes along with their calculations were given, which worked respectively for resistive, inductive and capacitive loads. The asymmetry factor affected by the non-ideal matching components and the fluctuating load was analyzed, and the resolution of suppressing the correspondingly produced negative currents was given. The experimental result verified on a 2 kVA balance transformer prototype shows that the proposed calculation formulas are valid and feasible.