The power industry in India has undergone an enormous change over the past decade and disruptive changes like large-scale integration of renewables and introduction of electric vehicles are impacting the utilities sector in the present time more than ever before. With smart utilities becoming the norm, large volumes of data are being generated that need to be stored, processed and analysed. This has led to the convergence of information technology (IT) and operational technology (OT), which have otherwise had an isolated history. With IT converging with OT and the wave of digitalisation taking over the industry, the operational excellence of businesses depends upon the smoothness of the interaction of IT with OT.
The near-real-time data generated from OT systems is required to be converted into streams of actionable intelligence using sophisticated IT software. OT, necessary to monitor the health of the power system, includes systems like supervisory control and data acquisition (SCADA), wide area monitoring system (WAMS), automatic generation control (AGC) and substation automation system. Meanwhile, the key enterprise IT applications include energy accounting and scheduling, short-term open access approval and its accounting, renewable energy forecasting, outage management system, automated meter reading, meter data processing and management information system. There is a rising pressure to increase reliability, maximise operational efficiency and simultaneously reduce the costs of a utility’s business. In this regard, an integrated approach to IT and OT brings in benefits in terms of better asset management, fault and outage management, increasing reliability and energy accounting.
SCADA in utilities
In India, there is a considerable diversity in terms of the location of load and the sources of power. To operate and manage power flows across regions and entities, there are 35 state-level load despatch centres (SLDCs), five regional load despatch centres (RLDCs) and a National Load Despatch Centre (NLDC). The gradual synchronous integration of regional grids has allowed for the free exchange of power between the regions. To coordinate and manage these regional and national connections, SCADA system is used as it has a wide range of components and communication protocols. The architecture of the SCADA system is such that it allows acquiring data by integrating all regional SCADA systems through high speed communication links on intercontrol centre protocol (ICCP). Further, backup systems have been established to maintain operational continuity in case of contingencies; and there is synchronisation between the main-to-main, main-to-backup and backup-to-backup systems. The major task here is to provide for an interface between the multivendor and multi-user systems across the regions.
SCADA has immense applications in load despatch centres. It enables visualisation of the current state of the grid with the help of various displays by using real-time data, animation effects and advanced alarm management system. SCADA also doubles up as an energy management system through grid state estimation, real-time contingency analysis, automatic generation control (AGC) and real-time security enhancement. Further, SCADA enables archiving the real-time data and using it for trend analysis in the future. The archived data can be used for reporting and analysing purposes.
WAMS is based on the new data acquisition technology of phasor measurement. It allows monitoring transmission system conditions over large areas for detecting and further counteracting grid instabilities. The synchrophasor technology allows monitoring phase angle separation across the grid. For instance, phase angle at the remote substation can be measured to check if the grid is under stress or not. Similarly, damping status and trends, oscillations, frequency variations, voltage fluctuations and power angle sensitivities can be analysed to detect the status of the grid. The implementation of WAMS in load despatch centres has various features such as hybrid state estimator, model validation, parameter estimation, oscillation detection and real-time detection of mode shapes to measure phase voltage and angle, phase current, frequency and circuit breaker (CB) status.
Further to that, the AGC pilot is under way at the NTPC Dadri Stage II thermal power project. AGC was operationalised in India in January 2018 on a pilot basis. As per the Central Electricity Regulatory Commission guidelines, AGC is under execution at Simhadri (southern region), Barh (eastern region), Mouda (western region) and Bongaigaon (north-eastern region). Further, the frequency bias mode and tie-line bias frequency mode operations are being studied besides configuring additional units on AGC. After successful testing, this technology is planned to be implemented across India in around 100 power generation plants. A total of around 65,000 MW is envisaged to be brought under AGC. The full-scale project, planned by 2022, will enable efficiency and grid security in the Indian power system, making it ready to handle the targeted 175 GW of renewable energy capacity.
Supporting OT with IT
Once the data is available, it has to be presented to the system operator. In other words, once OT has enabled the collation of data, IT comes into play with the techniques of fast and efficient visualisations. The visualisation technique must be such that it maximises understanding by enhancing perception and comprehension, and enabling projection. It must minimise visual stress, be high on information content and clearly identify the fault areas. IT also augments OT by providing various app-based or web-based portals to check for the status of applications for users, information dissemination and for handling short-term open access activities. To summarise, IT helps in fast and efficient analysis of the data collected by OT systems and helps the operator to make an informed decision while accounting for the system’s security and reliability.
Issues and challenges
Increasing automation and new technology addition (like smart meters) are generating exponential amounts of data, which need to be secured from cyberthreats. With continued security breaches, the focus should be on enhancing cybersecurity measures. Digitised electric infrastructure offers a high degree of digital complexity and a number of attack vectors. In such a scenario of various points of attacks, it becomes increasingly important to ensure cybersecurity across the sector. Various measures have been adopted for the same. For instance, there is an isolation of the IT and OT systems, such that there is no internal route from IT to OT or vice versa; data sharing is done only via the external route. The SCADA system architecture segmented has been into zones and conduits to create cybersecurity network architecture. Further a host-based intrusion prevention system has been deployed to protect the critical system containing crucial data against viruses and other malware. A network-based intrusion prevention system is also in place to monitor the network, and protect its confidentiality, integrity and availability. Further, utilities need to comply with the internationally set standard of ISO 27001, which calls for regular audits for compliance and regular cybersecurity tests by CERT [Computer Emergency Response Team]-In certified auditors.
The way forward
As utilities continue to embrace new technologies and invest in advanced systems, improvements are required on multiple fronts. The accelerating convergence between IT and OT calls for enhanced efficiency and productivity of systems. Hence, the methodologies and conventions used in OT must enable easy communication with IT.
That said, visualisation is the most important end product of the existing raw data. Improvements are needed to make visualisations more refined for the system operators. Further, the entire purpose of analysing the huge amounts of data is to make smarter decisions on the practical front. Hence, constant upgradations are needed for situational awareness tools, in order to mitigate the impending threats. Prior to that, transmission of data from sensors, smart meters, etc. would require efficient telemetry and communication in place. Lastly, as larger volumes of data are generated, storage would be a challenge and, therefore, the implementation of cloud-based solutions should be fast-tracked.
(Based on a presentation by Debasis De, General Manager, Power System Operation Corporation)