The most fundamental function of a smart grid is the integration of digital communication and automation system with the electric grid for more effective operation of the system.

Some of the key functions of the smart grid are listed here and explained in detail in the subsequent sections −

• Fault Current Limiting
• Wide area Monitoring and Visualization
• Automatic Control
• Dynamic Capability Rating
• Power Flow Control
• Adaptive Protection
• Automated Feeder and Line Switching
• Real Time Load Transfer
• Consumer Electricity use Optimization
• Remote Operation

Read this chapter to get a detailed understanding of each of these functions of a smart grid.

Fault Current Limiting in Smart Grid

The smart grid consists of a system to detect and limit or reduce the fault currents and protect the system equipment. This function is also responsible for maintaining the system stability.

Let us understand this fault current limiting function through an example.

Consider a short circuit or fault occurred in the grid which results in the flow of fault current. We know that the fault current is significantly higher than the normal operating current and hence it can cause potential damages to equipment.

But in a smart grid system, fault current limiters like superconducting FCLs are employed to minimize the magnitude of this fault current and limit it within a safer value. This function is crucial for protecting transformers, generators, and other equipment connected in the system. This also minimizes the chances of widespread outages.

Wide Area Monitoring and Visualization in a Smart Grid

Smart grids are responsible for real-time monitoring and visualization of grid’s data and parameters.

The wide area monitoring system of the smart grid uses time-synchronized sensors, phase measurement units which are distributed across the grid over a wide area. This system provides data like voltage, current, and frequency. This data is then visualized using a control system which enables grid operators to monitor the grid stability, detect the faults and disturbances, and take corrective actions accordingly.

Wide area monitoring and visualization is an important function of a smart grid and it is primarily helpful in improving grid reliability and better management of the grid operation.

Smart Grid and Its Automated Control System

A smart grid is equipped with an automated control system for managing the grid operations without any human intervention.

The automated control system regulates the voltage levels and power flow in the grid. It also controls and manages the operation of distributed energy resources.

The automated control system used in smart grid uses advanced control algorithms and real-time data for dynamic adjustment of settings of the grid. Consequently, it provides optimal performance and reduced energy losses. It also maintains the grid stability under varying load conditions.

Dynamic Line Rating in Smart Grids

Dynamic line rating is the function of a smart grid that adjusts the rating of grid elements like transformers, power lines, etc. depending on real-time conditions.

In a traditional electric grid, a constant rating of elements like generators, transformers, and lines is provided and this rating is given based on the worst-case conditions. But, in the case of a smart grid, the real-time grid data is used for adjusting the element’s ratings dynamically.

Dynamic line rating in Smart Grids improves the efficiency of the infrastructure and allows for higher power transfer with reduced risk of overloading.

Power Flow Control in a Smart Grid

Power flow control is an important function of a smart grid to control and manage the direction and amount of electrical energy flowing through the power grid.

For this purpose, several smart grid devices and technologies like Flexible AC Transmission Systems (FACTS) and High-Voltage Direct Current (HVDC) are used. These smart grid technologies can adjust the grid parameters such as voltage, impedance, phase angle, etc. to improve the reliability, stability, and efficiency of the electric grid.

Adaptive Protection in a Smart Grid

Adaptive protection means dynamically adjusting the protection settings as per the varying conditions of the grid to provide protection more effectively.

Conventional protection systems have fixed protection settings and hence they cannot be effective under all grid conditions. But in the case of a smart grid, adaptive protection systems are employed that use real-time grid data to change the relay settings and alter the protection schemes automatically.

Adaptive Protection ensures that the grid remains protected under different operating conditions and reduces the risk of unnecessary power outages.

Feeder Automation and Line Switching in a Smart Grid

Feeder Automation helps in improving the reliability of an electric grid, as it makes the grid capable of quickly isolating faults and reconfiguring the network for power transmission.

To implement this function, the smart grid uses automated switches, sensors, controls, communication systems, and reclosers. All these equipment work together to detect faults and execute the isolation and reconfiguration of the network.

By performing quick isolation of faulty parts and reconfiguration of the network for power supply through alternative paths, the smart grid reduces the power outage period and improve the consumer experience.

Real-Time Load Transfer in a Smart Grid

Real-time load transfer helps in dynamically shifting the electrical load between different segments of the grid to balance the supply and demand.

To implement this function, the smart grid uses real-time grid data and automated control system. The system switches the electrical load among different parts of the grid to avoid the overload condition and optimizes the utilization of system resources.

Real-time load transfer helps in maintaining the grid stability and improving the overall efficiency of the grid.

Optimizing the Energy Consumption of Users through Smart Grid

This function of a smart grid actively involves the consumers that helps in managing and optimizing the consumption of electrical energy. It is accomplished through two-way communication between supplier and consumers in real-time.

A smart grid can provide detailed information to consumers about their energy consumption. For this purpose, smart energy meters and internet technologies are used. This valuable data allows consumers to adjust their consumption pattern with dynamic pricing and demand response. Thus, it results in reduced electricity bills, improved grid reliability, and reduced environmental impact.

Operating a Smart Grid from a Remote Location

Smart grids use Internet and digital devices that can be operated remotely. A smart grid can help the grid operators to control and manage the grid components from a remote location.

Smart grids use communication and control systems to implement this feature. It enables the system to monitor and operate the grid equipment like transformers and circuit breakers remotely.

Operating a grid remotely reduces the response time, the need of on-site personnel, and operational costs.

Conclusion

This chapter covered the important functions of a smart grid in detail. All these functions are important for obtaining high efficiency, improved reliability and stability of the electric grid.

A smart grid uses several modern components and technologies to overcome the issues associated with the existing electric grids. In the next chapter, we will highlight the important characteristics of a smart grid.