Implementation of an on-line pre-decision based system protection scheme

The development of power network interconnection and power market calls for fundamental innovation on traditional system protection schemes (SPS). This paper describes the implementations of an on-line pre-decision system (OPS) based SPS in Shandong power system and Guangdong Shaoguan power system, which have been put into trial operation since May 2001 and September 2001 respectively. OPS-1 integrates EEAC technique for quantitative analysis of stability, an integer programming for nonconvex nonlinear optimization of transient stability control, an object-oriented distributed processing platform for contingency-oriented parallel computation, and a distributed emergency control system. OPS-1 carries out on-line stability calculation for the measured operating condition periodically, and the look-up decision table is refreshed accordingly. The new control decision table can be made available in 1 minute just after a change in either system topology or injection power and therefore OPS-1 is an ideal SPS solution to deal with system cascade outages.