Based on the former operating experience of RCS-915 series busbar protection products， a novel principle and technology is adopted for PCS-915 series busbar protections. An adaptive weighted algorithm based on the deviation power frequency component percentage differential protection， current transformer saturation criterion and harmonic restraint criterion is adopted， PCS-915 series busbar protections have strong ability to resist current transformer saturation and stable， reliable operation characteristics. Based on the implementation of new generation of protection and control hardware platform UAPC， it implements modularization both for software and hardware. So it is easy for the protection to upgrade and maintenance. The adopted new object-oriented busbar differential protection design method makes the differential busbar protection more flexible and reliable. It can easily meet the requirements of different main diagram in the power system. The distributed busbar protection uses the data link layer time locking synchronization scheme with less computing resource， not need to connect external synchronization source. The synchronization scheme is stable， reliable and with high accuracy.