Analysis and Optimized Suppression of DC Bias in Large AC Power Grid

Abstract

Although the calculation method of DC bias current distribution is mature, there is still a lack of unified standards for DC bias modeling and analysis in large AC power grid. The complex soil structure and various operation modes make the modeling and calculation process very cumbersome, leading to the difficulties in simulating the flow path of DC bias current in large-scale power grid. In order to improve the accuracy of DC bias simulation and rebuild the real topology of AC power grid, this paper proposes a set of modeling methods for DC bias simulation in large-scale AC power grid. Then, a multi-stage suppressing strategy combining simulation prediction and experimental observation is also put forward to improve the effectiveness of the DC-bias suppression scheme. Finally, the application of the above methods in Zhejiang power grid, which is affected by several DC grounding electrodes, is introduced.