PMU Based Monitoring of Inter-Area Oscillation in Thailand Power System via Home Power Outlets

This paper proposes a wide-area monitoring system of the inter-area oscillation between central and southern areas of Thailand power system using GPS-based synchronized phasor measurement units (PMUs). The PMUs are installed at two universities representing both areas. The phasor data of a single phase voltage 220 V are measured by PMU via a wall outlet. The phase difierence data between two universities recorded by PMUs are validated by comparing with the actual tie-line power ∞ow during steady-state conditions. The wavelet decomposition and least-squares regression are applied to identify the eigenvalue corresponding to the dominant interarea mode. Monitoring of variation of damping ratio and oscillation frequency of the eigenvalue in any period not only indicates the oscillatory behavior of the inter-area mode, but also provides useful information of the wide-area dynamic stability.