Introduction

Are you ready to travel the road to the intelligent grid?

Since the moment Thomas Edison commissioned the world's first power system in 1882, the electric power industry has continually moved forward - to improve the functionality, efficiency, and availability of electricity. Through evolutionary advancements in technology, the industry has transformed the way we generate, deliver, and consume power today. Now, it is once again on the verge of a transformation, as it works to develop an

Intelligent Grid to meet the needs of our digital society

Society's expectations and Utility Commission incentives/penalties are driving changes to the industry where secure data is required quickly, on-demand, and in an easy to search way. Customers are demanding higher reliability and greater choice, and are willing to examine and change their energy usage patterns.

To achieve the end-goals stated above, a unified vision of the road to the Intelligent Grid is needed. Without a unified vision, the issues currently facing the power system will be addressed piecemeal by utilities, government agencies, and related power system organizations.

The result of isolated development activities will be a power system that is plagued by islands of separation. Subsequently, the power system of the future may only be realized in limited areas or on a small scale. This article presents a definition of the Intelligent Grid and examines the road ahead to its development, only possible when power system organizations work together to provide a more capable, secure and manageable energy provisioning and delivery system. (IntelliGrid Architecture Report: Vol. 1, IntelliGrid User Guidelines and Recommendations, EPRI, Palo Alto, CA and Electricity Innovation Institute, Palo Alto, CA: 2002. 1012160.)

According to the IntelliGrid Architecture Report cited, the Electric Power Research Institute (EPRI) defines the Intelligent Grid as:

• A power system made up of numerous automated transmission and distribution (T&D) systems, all operating in a coordinated, efficient and reliable manner
• A power system that handles emergency conditions with 'self-healing' actions and is responsive to energy-market and utility needs
• A power system that serves millions of customers and has an intelligent communications infrastructure enabling the timely, secure and adaptable information flow needed to provide power to the evolving digital economy

From this definition, we can conclude that the Intelligent Grid must be:

• Predictive (operationally and functionally) to preclude emergencies
• Self-healing to correct/bypass predicted/detected problems
• Interactive with consumers and markets
• Optimizable to make the best use of resources
• Distributed in nature with both assets and information
• Transformational to turn data into information
• Secure from threats and hazards

The Intelligent Grid must provide robust, reliable, and secure communication as well as intelligent electronic devices (IEDs) and algorithms to make the necessary system assessments when needed. To achieve an Intelligent Grid, the industry must merge copper and steel (electricity generation and delivery infrastructure) with silicon and glass (computation and communication infrastructure). We are currently at the crossroads in the coming of age of both technology areas.

Over the past 35 years, we have seen communication speeds increase dramatically from 300bps (bits per second) to digital relays that today operate at 100Mbps - an increase of over 300,000 times! (Figure 1) Not only have the communication speeds changed, but the communication protocols have migrated from register-based solutions (e.g. - get the contents of Register 5) to text based data object requests (e.g. - get the Marysville-Kammer Line Voltages) as implemented through the IEC 61850 protocol. In addition, the physical interfaces have transitioned from RS-232 serial over copper to Ethernet over fiber or wireless - both local and wide-area. Interoperability has become a reality and today's devices are self-describing and programmable via a standardized configuration language.

On the device side, the IED and its constituent components have undergone an evolutionary convergence of multiple functions and features into a single device (Figure 2). In the past, protection, control, metering, oscillography, sequence of events (SOE), annunciation, and programmable automation logic were all separate functions. Today's IEDs combine these functions and more into a single platform that provides superior user interfaces allowing visual access to metering, SOE, device diagnostics/solution, and phasor views of data.