十二相4Y移15°绕组同步发电机三相交叉对接不对称突然短路电流分析

The Short-circuit Current Analysis of Sudden Unbalanced Three-phase-cross-connection of Twelve-phase Synchronous Machines with Four Y-connected Stator Windings Displaced by 15°

建立了十二相4Y移15°绕组同步发电机αβ0坐标系统的简化数学模型。用归纳法得出了三相交叉对接不对称突然短路统一的端点条件,并进行了简化,从而使解析分析得以大幅简化;根据叠加原理和谐波平衡原理,通过适当近似处理,用解析法分析了发电机三相交叉对接不对称突然短路电流,得出了统一的短路电流表达式和估算最大冲击电流的近似公式。通过试验进行验证,结果表明数学模型和分析方法是准确的。

Theαβ0 simplified mathematical model of twelve-phase synchronous machines with four Y-connected stator windings displaced by 15°is established,the general terminal conditions of the sudden three-phase-cross-connection unbalanced short circuits are obtained by the inductive method and simplified;and its short circuit currents are analyzed in detail by the principles of superposition and harmonic balance.The general expressions of short-circuit currents and the approximate formula of the maximum value of the short-circuit current are given.Comparison between the computed and measured results demonstrates the validity of the theoretical approach developed.