Analysis of Technical Key Points for Replacement of Busbar Differential Protection Devices in 220 kV Double-Busbar Connection Mode

With the growth of urban power load and the aging of old equipment, the renewal and transformation of busbar differential protection devices have become crucial for ensuring the stable operation of the power grid. This paper analyzes two busbar differential protection transformation schemes: complete busbar shutdown and no-power-off transformation. Although the complete shutdown method is simpler, it has a greater impact on the operation of the power grid. The no-power-off transformation is implemented in stages, including preliminary preparation, interval-by-interval shutdown connection, and live connection transfer, which effectively reduces the duration and risks of power outages. The paper focuses on the key links and risk points of the no-power-off transformation, proposing detailed connection procedures and precautions.