Development of a real-time power system dynamic performance monitoring system

Power systems have grown in both size and complexity, and the dynamic characteristics of the systems vary, as well. A computer simulation revealed the possibility of low-frequency oscillation after the connection of a cogeneration plant to the utility grid. Though there are several possible methods to improve the dynamic stability performance of the system, a thorough understanding of the system characteristics and possible operating conditions is required before an appropriate measure can be proposed. In order to collect more operating information without affecting normal system operation, a programmable logic controller (PLC)-based dynamic performance monitoring system (DPMS) was designed and installed at the tie substation. The recorded information will be valuable for system analysis and/or power system stabilizer (PSS) design. The DPMS design, its laboratory testing results, and several field-operation records are discussed in this paper.