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Power Transformers

Three-Winding Transformer Models

Description

Three-winding transformer models show how three identical single-phase transformers can be combined into a three-phase transformer connection. The high-voltage windings are labeled A, B, and C. The low-voltage windings are labeled a, b, and c. This notation separates the high-voltage side from the low-voltage side and matche...

Transcript

三个相同的单相变压器通过四种绕组类型中的高压端子和低压端子连接,构成三相连接。

接地Y-Y变压器的标幺值等效电路中的基准量包括一个公共的基准视在功率,以及与额定线间电压比相匹配的电压基准比。

该变压器中的平衡电流产生零中性线电流,使其标幺值等效电路类似于单相理想变压器。

通过扩展双绕组变压器方程,可得到单相三绕组变压器所需的关系式。

这些关系式用实际值和标幺值表示时,满足标幺值等效电路。

实际的三绕组变压器电路包含外部串联阻抗和并联导纳支路,这些参数通过开路试验进行测定。

当一个绕组开路时,三绕组变压器的作用类似于双绕组变压器。标准的短路试验用于评估标幺值漏电抗,通过忽略并联导纳支路可进一步简化分析。<...

Tags

Per Unit Equivalent CircuitGrounded Y Y ConnectionOpen Circuit TestShort Circuit TestLeakage ImpedancesShunt AdmittanceVoltage Base RatioNeutral CurrentsSeries Impedances