Study on protection scheme of integrated power system

This paper discusses protection scheme of integrated power system (IPS), which can reduce fuel consumption and increase operation flexibility. Conventional over current protection can´t be applicable to IPS directly due to great difference and variety of its operation mode, which can be amended by current differential protection and voltage blocking over current protection. A novel automatic reclosing logic is presented to correct unselectivity tripping of not vital load. Main protection of IPS consists of current differential protection, time-graded over current protection and the novel automatic reclosing logic, which has selectivity and can maintain system stability after short circuit fault is isolated. Backup protection of IPS consists of time-graded voltage blocking over current protection and over current protection, which has selectivity and reliability. The presented protection scheme meets performance requirement of system protection and adapts variety of its operation mode, which can lay foundation for safe and stable operation of IPS.