DC GRID CURRENT DIFFERENTIAL PROTECTION METHOD AND SYSTEM THEREOF

摘要

A DC grid current differential protection method and system are provided. The method includes: sampling value acquiring step (S301): acquiring pole voltage and current sampling values in local and remote terminal of a DC line; fault component extracting step (S302): calculating fault component pole voltage and current values according to the pole voltage and current sampling values of local and remote terminal respectively; Bergeron model calculating step (S303): acquiring fault component pole current values at selected point on the DC line between the local and the remote terminal, by the calculation of the fault component pole voltage and current values of local and remote terminal calculated in the fault component extracting step, based on Bergeron model; current differential protection judging step (S304): judging internal fault if the fault component pole current values at selected point meet preset current differential protection criterion. Because of adopting Bergeron model, it improves the calculating speed.