A Comprehensive Review on Wide-Area Protection, Control and Monitoring Systems

In recent days electrical power system experiencing a rapid change thereby inclusion of advanced equipment and expansion of transmission/distribution network. Besides the modernisation of existing power system network, a number of renewable energy sources such as wind parks and solar parks etc., have been integrated to balance growing power demand due to the industrialization and digitalization. However, a secure and dependable operation of power system network is not so easy because of its complex nature in terms of control, operation and maintenance of various components in wide-area network. Inspite of gigantic developments in power system operations, components and protection technologies, today’s power systems are more susceptible to blackouts than ever before. In this context some of the recorded major blackout incidents have been classified according to the time and location as of research reference purpose. As per the survey the frequency of occurrence of blackouts is increased over time. Practically, it is not possible to avoid blackouts completely; though, various research studies and number of research articles were acknowledged that by taking some rationally gainful measures, incidence of the blackouts could be abated and/or their effects could be mitigated. The forthright approach is to minimize the peril of unplanned disturbances thereby extenuating opportune paradigms to the extent that possible, the root causes of the disturbances through analyses and audits followed by initiating various preventive and corrective actions. In view of the preventive and corrective actions to avoid wide-area disturbances, a new paradigm has been embraced with Wide-Area Protection, Control and Monitoring (WAPCAM) system. With the rapidly growing capabilities in advanced computer and communication technologies such as Intelligent Electronic Devices (IEDs) enabled Remote Terminal Units (RTUs), Global Positioning System (GPS) enabled Phasor Measurement Units (PMUs); opportunities are now being available to adopt the Wide-Area Protection, Control and Monitoring (WAPCAM) system. Such systems receive wide-range of data or information e.g. system-wide bus voltages, angles, active and reactive power flows, etc., and by analysing them, can estimate whether the system is at stressed condition or not. By taking coordinated actions, the power system network can be saved from proceeding to total collapse, or even, mitigate the wide-area disturbance effects upon the system. WAPCAM system has different level of hierarchies in realization of preventive and corrective actions such as local feeder level, sub-station level and central/regional level. One of the recommended preventive plans against the wide-area disturbances and the blackouts is Wide-Area Protection and Control (WAPC) system that includes Special Protection Schemes (SPS) (or) System Integrated Protection Schemes (SIPS) (or) Remedial Action Schemes (RAS) based on an advanced communication infrastructure etc. To mitigate the impact of wide-area disturbances, the remedial/corrective actions have been initiated by implementing Wide-Area Stability and Control (WASC) system that embraces power system stabilizers (PSS) and ON-Load Tap Changers (OLTC) and Wide-Area Monitoring and Control (WAMC) system. It also includes out-of-step (OSS) bus splitting and optimal islanding schemes etc. Although; the power system exhibits unstable dynamic phenomena at stressed conditions such as Transient Angle Instability, Voltage Instability and Frequency Instability, the WAPCAM has to bring back the power system to normal restorative condition as soon as possible. This chapter enlightens a comprehensive research review and explicates different type of WAPCAM systems that can address the major blackouts to improve stability, reliability and security of power system networks. A comparative assessment has been explicated by summarizing various recently reported conventional and intelligent schemes. It also enlightens the research insights to power system researchers and protection engineers while planning and designing of stable, reliable and secured power system networks.