220kV变压器中性点隔直技术的研究与应用

Research and Application of 220kV Transformer Neutral Point DC Blocking Technology

直流输电系统单极大地回线方式或双极不平衡运行时电网内中性点直接接地运行的变压器产生直流偏磁,影响变压器及系统稳定运行。针对以往中性点隔直技术的不足,研究了采用双向可控硅配合快速旁路开关保护电容的电容隔直装置及其控制投退策略,通过220kV德隆站应用实例分析,验证该装置的实用有效性。

When the DC transmission system is in unipolar ground return mode or bipolar unbalanced operation,the transformer that operates directly from the internal neutral point of the power grid generates DC bias,which affects the stable operation of the transformer and the system.In view of the shortcomings of the previous neutral point DC blocking technology,a capacitor DC blocking device using bidirectional thyristor and fast insertion of switch protection capacitor and its control switching strategy were studied.The application of 220kV Delong station was analyzed to verify the practicality of the device Effectiveness.