一起220kV变压器绕组变形故障分析

Analysis of 220kV Transformer Winding Deformation

绕组变形是变压器发生近区短路时损坏的主要原因。江苏电网220kV变压器多采用自耦结构,早期的变压器阻抗值选择较低,抗短路能力较差,在近区短路时容易发生绕组变形故障,造成变压器突发故障。文中对一起220kV自耦变压器绕组变形故障进行分析,提出变压器发生绕组变形的判据;通过解体分析验证了低电压短路阻抗测试、电容量及介损等测试方法对于判断变压器绕组变形判断的有效性;对发生近区短路后的变压器提出诊断的方法,确保变压器安全运行。

Winding deformation is the main reason of transformer short circuit which results in damage. In Jiangsu province, the 220 kV auto-transformers are commonly used in the 220 kV power grid. The low impedance value and poor anti-short circuit ability of earlier transformers may result in winding deformation fault and unexpected accident. This paper analyzes a fault of 220 kV autotransformer winding deformation and thus proposes a criterion for judging transformer winding deformation. The disintegration analysis of transformer winding proves that the comprehensive analysis method that combing the low-voltage short-circuit impedance test and the capacity and dielectric loss test is effective, A new way to diagnose transformer winding deformation is proposed to ensure safe and stable operation of transformers.