Morrow and Brown Case Study Summary
In their work, Morrow and Brown discussed the expectations that professionals have regarding the development of improved transmission systems that can address the associated energetic and economic issues. The authors also focused on challenges that can be faced by the developers of the new transmission system in the United States. Morrow and Brown start their discussion by noting that even though the U.S. transmission systems were reorganized in large systems to realize the complex energy transactions, new approaches to planning are necessary.
In the future, the role of the power producers and power purchasers’ location will decrease, and the new system should be complex and broad (Morrow and Brown 296). The need for a specific and well-planned transmission grid is also explained with references to the fact that the current transmission infrastructure is outdated, and it needs to be improved to become more efficient.
After accentuating the necessity of the new transmission system and the associated planning, the authors focused on the benefits of transmission systems in general. Thus, effective transmission guarantees lowering the electricity costs; organizing efficient power markets; providing them access to alternative resources of energy, as well as to renewable energy; decreasing the dependence on changes in fuel prices; improving operational flexibility. However, Morrow and Brown emphasize the aging of the infrastructure and system one more time while stating that the existing transmission lines and power transformers are old, and they can guarantee only the limited transmission capacity. Therefore, the investment into new lines is necessary to plan and develop a more efficient transmission system.
Much attention is paid to the discussion of planning, technical, and infrastructure development challenges associated with the organization of the new transmission system nationally. Planning challenges include issues before and after the open access that involve questions of creating the coordinating committees and removing the barriers to the market for producers and purchasers. The authors also focus on the planning referring to the role of regional transmission operators (RTOs) who become responsible for organizing the effective regional planning process (Morrow and Brown 298). In this context, the challenges are associated with determining who must decide which projects should be built and who must approve these projects.
Technical challenges include the issues of reliability, congestion, and application of new technologies. In this case, reliability means how the transmission system can respond to possible faults and contingencies. If the challenge is addressed, the response of the system does not interrupt the overall load. The associated problems include equipment failures, difficulties with planning wide-area systems, and planning for congestion. Finally, the application of new technologies leads to problems connected with the development of new processes and the use of new tools. Infrastructure development challenges include the focus on environmental issues, the response to the public’s reactions, as well as issues associated with financial, political, and regulatory pressures.
While discussing the future perspectives, the authors note that it is important to develop a well-organized planning process; focus on the roles of transmission operators in addressing not only local but also broad planning issues; not only plan but also develop the system while addressing the regulatory questions; make the planning process transparent; involve the public. Furthermore, the authors state that it is possible to expect success in planning the transmission system while addressing the needs of the developer.
Dufournet Case Study Summary
In his work, Dufournet focused on discussing several interrupting techniques that are effective to reduce the operating energy associated with the work of circuit breakers. The author is interested in analyzing circuit breakers that have high voltage ratings. The focus is on the high-voltage sulfur hexafluoride (SF6) breaker. Currently, such circuit breakers that have self-blast interrupters are widely used. Dufournet notes that the reason is in the high interrupting capability of these breakers that can lead to decreasing the operating energy and costs, as well as to increasing the reliability. The author notes that when the first SF6 circuit breakers were proposed, they met the designers’ expectations.
Dufournet also pays attention to the history of circuit breakers. During the period of the 1900s-1950s, bulk oil circuit breakers were used. In the 1950s, they were changed with minimum oil circuit breakers that contributed to improving the arc cooling process. The air-blast circuit breakers were also introduced during this period, and they became popular in North America and Europe because of their high interrupting capability that changed from 63kA to 90kA in the 1970s.
The puffer-type technique was proposed to be used for high-voltage circuit breakers in the 1960s, and it was developed because of its attractive properties and high interrupting capability (about 800 kV). Although SF6 puffer-type circuit breakers were developed in the 1930s, and they were applied for the first time in the 1950s, they became used actively only in the 1980s.
While focusing on characteristics of the SF6 puffer-type technology, Dufournet points at the simplicity of the utilized interrupting chamber, its autonomy, the increased performance, the decreased number of interrupting chambers and interrupting time, the improved reliability, the increased availability, and the decreased noise level. The designers accentuated the simplification of these improved circuit breakers that contributed to the reduction of the operating energy.
In this context, the author describes the self-blast technology in detail because the development of this technique allowed improving SF6 circuit breakers. This technology is used to optimize the interrupting chamber, control the interruption of the arc, and the distribution of the arc energy that can also affect the valve and have the overall thermal effect in the system. This process leads to decreasing the operating energy. The other accentuated principle is the double motion that was developed to optimize the self-blast technology. Still, in this case, the reduction of the operating energy is also observed in association with the reduction of the kinetic energy (Dufournet 423).
The process also involves the work of the arcing chamber and the upper contact system. While discussing technologies, Dufournet also pays attention to generator circuit breakers that are used to control the work of both transformers and generators. The system is protected, and operations depend on the work of the thermal blast chamber and the self-blast chamber. Dufournet concludes that all these technologies used to improve the work of circuit breakers are effective to reduce the operating energy. In the future, it will be possible to establish new technologies to make the process more efficient.
Horowitz, Phadke, and Renz Case Study Summary
Horowitz, Phadke, and Renz concentrated on the discussion of approaches to modernizing the transmission of electric power in the United States, and they also focused on the aspects of the power distribution in the country. The authors identified five key technologies areas (KTAs) that include the advanced control with the focus on its features and methods, the advanced protection, the advanced components with the focus on flexible ac transmission systems (FACTS), the sensing and measurements, the decision support, and the integrated communication to unite all these areas.
Horowitz, Phadke, and Renz paid attention to the fact that the application of technologies associated with these areas in the transmission process will not affect large central power plants. Furthermore, the authors accentuated the importance of studying the past of the transmission system, as well as the history of its development, to understand its current and future trends.
The authors mentioned the foundation of the National Electric Reliability Corporation that provided the guidelines to address the problems in transmission systems that were observed in the 1960s. Much attention was paid to the interaction between utilities. However, despite the application of guidelines and directions, in 2003, the United States and Canada faced a significant power problem (Horowitz, Phadke, and Renz 519). The issue was in ignoring the recommendations regarding the load and stability in the power transmission. The situation demonstrated the necessity of the transmission enhancements.
Among these improvements for the transmission system, Horowitz, Phadke, and Renz distinguished the advanced control with the focus on the work of FACTS devices. The reason is that the control can increase capability about the power transfer. The other necessary enhancement is the advanced protection based on the application of special protection systems. The transmission systems are often discussed as stressed ones, and much attention should be paid to the protection of the systems’ work.
Security is guaranteed with the focus on the current measuring relays. However, for future development, the computer relay is the preferred alternative for the protection to control, monitor, and analyze the received data effectively. The utilization of this technology allows meeting the requirements regarding the monitoring and analysis of the data and prediction of the power instability and further problems.
Other enhancements also include the use of the synchronized phasor measurement based on measuring sequences and power currents and the use of the automatic calibration of transformers. These technologies allow the effective control and protection of the system and the calibration that is not influenced by errors in the work of transformers. Moreover, the authors refer to measurements and estimates to improve the understanding of the processes in power system operators. These approaches should be implemented to predict and avoid challenges associated with collecting the data for the analysis. In the future, this information can be analyzed with the help of computers.
Finally, the authors discuss the technologies used to address the complete and incomplete observability with the help of phasor measurement units (PMUs) and estimates made for interconnected power systems in the United States. The problem is in the fact that different parts of the system are under the control of different centers, and this issue should be addressed with the help of correcting the current approaches and proposing the new systems.
Besides, Horowitz, Phadke, and Renz mentioned the intelligent visualization techniques that are used to address the issues associated with bus voltages, as well as line flows. Referring to the analysis of the proposed enhancements, the authors conclude that further technological development is required in the sphere because the improvement of the power system is one of the priorities in the United States.
Works Cited
Dufournet, Denis. “Circuit Breakers Go High Voltage.” Power System Analysis and Design. Ed. Duncan Glover, Mulukutla Sarma, and Thomas Overbye. New York: Cengage Learning, 2011. 420-425. Print.
Horowitz, Stanley, Arun Phadke, and Bruce Renz. “The Future of Power Transmission.” Power System Analysis and Design. Ed. Duncan Glover, Mulukutla Sarma, and Thomas Overbye. New York: Cengage Learning, 2011. 518-524. Print.
Morrow, Donald, and Richard Brown. “Future Vision: The Challenge of Effective Transmission Planning.” Power System Analysis and Design. Ed. Duncan Glover, Mulukutla Sarma, and Thomas Overbye. New York: Cengage Learning, 2011. 295-299. Print.