参数差异化500kV单相自耦变压器成组运行适应性研究

Study on the adaptive operation of 500kV single phase autotransformers with different parameters

三相参数不一致将导致500kV单相自耦变压器运行性能变差,甚至带来安全风险。为了评估参数差异化500kV单相自耦变压器成组运行的性能和风险,结合河北南网500kV变压器的轮换检修,搭建了500kV变压器组的仿真模型,计算了变压器组各序电压、电流、空载环流、低压绕组环流、中性点电流等参数,结合采购标准确定了2台新制334 MVA单相自耦变压器的最佳短路阻抗,进一步分析了变压器三相参数差异对暂态过程的影响,评估了保护误动和拒动的风险。结果表明,在500kV单相自耦变压器组高-中压短路阻抗有名值差异不大的情况下,变压器稳态运行性能较好,该研究为参数差异化的500kV自耦变压器成组运行提供了经验参考。

The inconsistency of the three phase parameters will lead to poor performance of the 500 kV single-phase autotransformer, and even bring security risks. In order to evaluate the influence of parameter difference of 500 kV single-phase autotransformergroup on its operating performance and risk, a simulation model of 500 kV transformer group is set up based on thealternate maintenance of 500 kV transformer in Hebei Southern Power Grid？ the transformer group sequence voltage and current, no-load circulation, low pressure winding circulation and neutral point current are calculated, and combining with the procurementstandard, the optimal short-circuit impedance of 2 new 334 M V A transformer is determined. The influence of transformerthree-phase parameter difference on the transient process is analyzed？ and the risk of maloperation and rejection of pro-tection is evaluated. T he resuts show that when the difference of the actual short-circuit impedances of high-medium voltageside in 500 kV single-phase autotransformer group is sm all, the steady state performance of the transformer is better. Theresults show that the combination operation of 500 kV single-phase autotransformers with different parameters is feasible andhas reached a good level in transient and steady-state performance.