Abstract:

The busbar is the core device of collecting and distributing electric energy in substation.When the busbar fault occurs, the failure to clear it promptly will damage numerous equipment and even undermine system stability in severe cases. Therefore, it is very necessary to set up a busbar protection with reliable operation and strong selectivity, which is also required to quickly detect the fault within the busbar range and selectively remove the fault in time without expanding the power failure range.A rare case of 10 kV busbar protection misoperating when the crossing fault occurs due to the wrong setting of the internal differential current calculation program of the microcomputer protection is analyzed. The relevant measures are put forward.A busbar protection verification method which can check the internal calculation program of the protection device is designed accordingly, which has achieved favorable results in practical applications.

Key words: busbar protection, differential protection, protection configuration, maloperation, protection check