Monitoring and State Estimation of Modern Power Systems

The modern power systems require higher levels of secure and reliable power applications for monitoring and controlling the energy of the future cities. The power system state estimation utilises the acquired measurements to deduce the state variables (voltage magnitudes and their phase angles) of the power system. The accuracy and numerical stability of the state estimation is an essential part of the basic unit of the security analysis system in energy control centres. The conventional state estimator is solved by an iterative approach that is sensitive to erroneous measurements. On the other hand, the inclusion of the distribution systems, the radial feeders and the inclusion of the phasor measurement units (PMUs) yield new challenges to the state estimation. This chapter discusses the reasons beyond ill-conditioning, the factors that affect the quality of the state variables, the numerical stability of the state estimator, bad data detection and the available research gaps. Moreover, the presence of high-influential measurements, collinear measurements and their impact on security attack and false data injection are discussed in this chapter with proposing the required solution. However, due to the dual nature of the state estimation (a computer-aided application that is based on the available measurements), the responsibility of enhancing the state estimation is shared among the utilities, the operator and the programmers. Hence, this chapter investigates the problem of enhancing the state estimation by utilising the state-of-the-art statistical studies, measuring devices and meter-based methodologies.