Introduction

Spread over the grid, sensors and sensor networks monitor the functionality and the health of grid devices, monitor operation conditions, provide outage detection, and detect power quality disturbances [1]. Control centres can thus immediately receive accurate information about the actual conditions of the grid. Applications of sensor and actuator networks in power systems can be categorized based on the subsystems they are employed in, namely, generation systems, power transmission systems, distribution systems, and consumers.

In generation systems, sensor networks can be utilized to improve the efficiency of and monitor the conditions of the generation systems. For example, automated panels managed by sensors track the Sun's rays to ensure that solar power is gathered in a more efficient manner [2]. Sensors can report the structural health condition of wind turbines [3] and hydro dams continuously, as well as wind speed and direction for monitoring wind power generation [4].

On the transmission side, since active power flow in a power line is nearly proportional to the sine of the angle difference between voltages at the two terminals of the line, phasor measurements are important to the planning and operational considerations in a power system. Phasor measurement units (PMUs) have been deployed at substations that facilitate such measurements. The IEEE standard on synchrophasors (C37.118) governs the format of data files created and transmitted by PMUs, allowing interoperability among multiple device vendors. In addition to PMUs, other types of sensors have been used in practice.