New design of PMU for real-time security monitoring and control of wide area intelligent system

Security monitoring and control are very important for stable operation in wide area intelligent system. Electrical power grid is one of a wide area system and is progressing to intelligent system. For real-time security monitoring and control of electrical power grid, measurement of control variables such as voltage, current, real power, reactive power, power factor and system frequency must be synchronized because sub-control sites are distributed widely. Global Positioning System (GPS) is used for synchronization. In this paper, we introduce the new design concept of Phasor Measurement Unit (PMU) for security monitoring and control of electrical power grid, which is one of the wide area intelligent systems. PMU is applied d-q transformation and Phase Locked Loop (PLL) to improve the robustness of measurement. PMU is tested on three-phase 380V distribution line with resistor load.