Research on the design and experiment of power transformer DC bias blocking device

The monitoring and measurement results indicate that, severe influence may be brought to electromagnetic devices of power systems such as power transformers by DC bias effects. So, DC bias blocking device must be designed and manufactured to ensure the safety and stability of the power systems. In this paper, optimized analysis were done on the DC current blocking scheme based on the existed dual protection topology, and the selection and design parameters principle of the device was given according to the relevant principles. Combined with the specific structure and parameters of Shandong peninsula grid, a prototype was developed, and a series of tests were done on it with the data gotten from debugging. The experiment results showed that both the hardware and software can work reliably and the device can be used to the production field.