SCADA and Smart Energy Grid Control Automation
In my current research on artificial intelligence for the control of Distributed Energy Resources (DERs) in subgrids (microgrids) the importance of SCADA systems, its architecture and communication infrastructure with respect to energy management for power systems are briefly discussed. The emergence and evolution of the smart grid concept for managing electric power grids have presented several avenues for enhancing efficiencies and overall effectiveness. Smart grids as electricity networks utilize utilizing digital technology to deliver electricity from suppliers to the consumers by using two-way digital communications to control appliances at consumer’s homes. It can save energy, reduce costs and increase reliability and transparency. The Smart Grid is envisioned to overlay the ordinary electrical grid with an information and net metering system that includes smart meters. One promising approach involves the utilization of supervisory control and data acquisition (SCADA) systems, offering a convenient framework for remotely controlling and monitoring renewable energy sources (RES). Widely employed across diverse industrial sectors, SCADA systems have played a significant role in optimizing operational efficiency within these systems.
SCADA (Supervisory Control and Data Acquisition) systems play a crucial role in the field of smart grid management. Their primary function is to oversee and regulate various elements of the power system, including other primary grid components like generators, transformers, and transmission lines, in real-time. For smart grid automation/control , SCADA systems function as process control systems (PCS) that collect, monitor, and analyze real-time environmental data, whether from a straightforward residential building or an intricate large-scale PV or wind farm power plant. These systems may include various types of data acquisition devices, such as remote terminal units (RTUs) and/or programmable logic controllers (PLC), which are interconnected with a range of field devices like sensors, digital meters, protection relays, and station alarms (batteries, chargers, and fire alarms). By gathering data from remote devices, SCADA systems transmit it to a central control room, enabling analysis for informed decision-making regarding the smart grid. In the case of an unforeseen power outage, the SCADA system can swiftly detect the issue, pinpoint its origin, and autonomously isolate the affected area to minimize its impact on the broader system. This capability aids in reducing downtime and enhancing the overall reliability of the power system. Control systems, computer-based systems employed in various critical infrastructures and industries like the electric grid, natural gas, water, and wastewater sectors, are utilized for monitoring and managing sensitive processes. In the implementation of smart grid systems, there is a growing inclination to integrate SCADA with data networks. These control systems are responsible for gathering field measurement and operational data from field stations, processing, and displaying this information. Additionally, control systems may carry out supplementary control functions, including operating switches and circuit breakers, and adjusting valves to regulate the flow of fuel.
Beyond monitoring and control, SCADA systems offer opportunities to optimize power system operations. This includes tasks such as lowering energy consumption, enhancing the efficiency of power generation and distribution, and ensuring adherence to environmental regulations. Using control systems in power system applications has become increasingly attractive during the past few decades; they are applicable in large-scale renewable energy systems, such as wind and solar farms. SCADA systems for renewable energy are computer-aided control systems, sometimes called renewable energy management systems (EMS).
Energy Management Systems (EMS) have undergone significant advancements, driven by the intelligence and enhanced capabilities of application software. The demand for data acquisition electronic devices and associated communication systems within control centers has pushed the boundaries of available computer and communication technologies. Specifically tailored systems and devices have been developed to meet the evolving requirements of power system applications, leveraging advanced information and emerging communication technologies. The shifting landscape of control industry deregulation has prompted a reevaluation of the requirements for electricity supervisory control centers, revealing their shortcomings. Traditional control centers were characterized by rigidity, independence, excessive centralization, and closed systems, which no longer align with modern standards. The evolving needs of contemporary power system operations necessitate a transition towards distributed control centers that are decentralized, flexible, integrated, and open. Present-day control centers are gradually adapting to these changes, albeit with varying degrees of success, as they move towards a more distributed and flexible operational model.
The primary function of a SCADA system in a smart grid is to facilitate distributed generation, switching procedures, alarms, telemetry, event logging, measurement recording, and remote control of outstation equipment. The evolving changes in recent power system operational needs demand a distributed control center that is decentralized, flexible, integrated, and opened
A contemporary SCADA system should align with engineering plans by providing access to power system data without disrupting any operational workstations. SCADA technologies have been employed in today’s control centers to enhance power distribution in smart grids in line with the advent of the Internet age, shifting towards microgrid, grid computing and web services. SCADA systems have traditionally used combinations of radio and direct serial or modem connections to meet communication requirements, although Ethernet and IP over SONET / SDH is also frequently used at large sites such as Railways and Power Stations. The remote management or monitoring function of a SCADA system is often referred to as telemetry.
Main Components of a SCADA System
- Human Machine Interface (HMI): HMI software offers operators a visual representation of the process, enabling them to monitor and interact with the system.
- Remote Terminal Units (RTUs) and Programmable Logic Controllers (PLCs): RTUs and PLCs gather data from field devices and execute control commands.
- Communication Network: This network interconnects all system components, facilitating data transfer and control commands among them.
- SCADA Software: The software processes and stores collected data while enabling control actions.
Functions of a SCADA System
- Establishment of communications
Configure and initialize each RTU with input/output parameters
Download control and data acquisition programs to the RTU
2. Operation of the communication Link
For master slave arrangement, poll each RTU for data and write to each RTU
Log alarms and events to hard disk
Link input and outputs at different RTUs automatically
Smart Grid and SCADA Integration
One of the considerations in designing the capabilities of the smart grid is the integration of SCADA systems to enable the remote control of electric microgrids and grids, supervise and control the electric network equipment as a means of fulfilling reliability and desired efficiencies for the whole utility. The smart grid framework encompasses and focuses on distributed intelligence, incorporating elements such as data decentralization, renewable distributed generation, energy storage, and distribution system automation. At its core, the smart grid involves real-time data monitoring and active smart grid management achieved through swift two-way digital communication, utilizing technological solutions to enhance the power delivery infrastructure.
Integration is a key feature, linking subgrids like microgrids and various entities within the electric utility, including renewable power generators, consumer load devices, and third-party entities such as consumers, vendors, or regulatory organizations. The smart grid includes an intelligent monitoring system that oversees the flow of electrical energy across the power network, utilizing cables or transmission lines to manage fluctuations, losses, and the integration of cogeneration from solar, fuel cells (FC), and wind. The integration of SCADA into the smart grid involves utilizing electrical, communications, and data networks, enabling the distributed and centralized aggregation of information and control throughout the entire electrical utility network. Playing a crucial role in making the grid self-healing, automatically responding to power quality issues, outages, and system faults, SCADA integrates swiftly to enhance smart grid efficiency. Additionally, it monitors and optimizes grid assets, contributing to the reduction of operations and maintenance costs. This comprehensive approach includes both fixed and mobile devices within the architecture of the smart grid. Beyond normalizing electric demand, the ability to manage power consumption peaks aids in preventing brown-outs and black-outs during periods of high demand, ensuring the continuous operation of critical loads and devices.
SCADA software plays a crucial role in facilitating dynamic grid management by monitoring line segments and control points within the electric network. SCADA plays a pivotal role in the integration of smart grids within smart cities. It collects data from sensors embedded in the grid infrastructure, monitoring electricity distribution, demand, and potential faults. By utilizing this information, SCADA enables utilities to make real-time decisions, such as rerouting power to prevent outages or optimizing energy distribution based on demand patterns. This ensures efficient and reliable electricity supply for the growing needs of smart communities.This entails analyzing, organizing, and utilizing a significant amount of data for both online and offline decision-making, which can be facilitated by software installed on power application servers. Decentralized SCADA software is particularly important due to the significance of SCADA devices, data acquisition, and computational abilities, which prevent reliance on a centralized data acquisition solution. Intelligent Electronic Devices (IEDs) play a key role in organizing, collecting, and analyzing data for decision-making, switching management, data routing, and other necessary control actions based on operational status. This functionality is embedded either in the devices’ firmware or via configuration functions and settings within each device.
Advantages and Drawbacks of SCADA for Grid Control
- Real-time Monitoring: SCADA systems enable the real-time monitoring of power system components, facilitating swift identification and response to potential issues.
- Enhanced Efficiency: SCADA systems contribute to optimizing power system operations, minimizing energy waste, and improving the efficiency of power generation and distribution.
- Improved Reliability: SCADA systems enhance power system reliability by promptly addressing potential problems, lowering outage risks, and ensuring proper maintenance of power system assets.
- Integration of Renewable Energy: SCADA systems aid in managing the integration of renewable energy sources, such as wind and solar power, enhancing overall grid efficiency and reliability.
On the other hand, the disadvantages of using SCADA in power systems are:
- Complexity: SCADA systems can be intricate and demand specialized knowledge for operation and maintenance, posing challenges for some utilities.
- Cybersecurity Risks: SCADA systems are susceptible to cyber attacks, posing potential threats to the security and reliability of the power system.
- Data Management: SCADA systems generate large volumes of data, which can be cumbersome to manage and analyze.
In conclusion, the increased functionality of SCADA and the Smart Grid architecture leads to control systems that are escalating in complexity and have become time critical, embedded, fault tolerant, distributed, intelligent, large, open sourced, and heterogeneous, all which pose their own program vulnerabilities. Ranked high on the list of government concerns are threats against SCADA systems. Regrettably, largely due to the intricacies and resource demands, the threats are frequently underestimated, and many organizations are slow to adopt enhanced security measures to counter these challenges. Vital areas for addressing these threats include safeguarding critical paths, implementing robust safety policies and procedures, fostering knowledge management, and cultivating system development skills that prioritize security architecture as a fundamental requirement.
