EPRI and Entergy validate voltage stability monitoring method.
Press Release Summary:
To help power system operators prevent voltage collapse, EPRI and Entergy Corporation have validated method developed by EPRI for continuously calculating voltage stability margin on transmission networks using measured voltage and current waveforms at transmission substation level. Calculated voltage stability margins provide important indices to help power system operators anticipate system-wide instability problems.
Original Press Release:
Entergy and EPRI Validate Measurement-Based Voltage Stability Monitoring Method to Improve Grid Reliability and Operator Effectiveness
New approach offers the potential to provide an online real-time safety net to prevent voltage collapse
PALO ALTO, Calif. - (January 9, 2009) - The Electric Power Research Institute (EPRI) and Entergy Corporation (Entergy) have validated a method developed by EPRI for continuously calculating the voltage stability margin on transmission networks using measured voltage and current waveforms at the transmission substation level. The method promises to overcome limitations of traditional methods that rely primarily on simulation-based methods and promises to help power system operators prevent voltage collapse.
The offline validation was conducted on the western region of Entergy's power system and demonstrated how voltage instability margins can be calculated in real time using data from selected transmission substations. The calculated voltage stability margins provide important indices for power system operators to monitor and control voltage stability.
"It is extremely challenging to assess voltage stability in a continuously changing electric system," said Sharma Kolluri, manager, transmission planning at Entergy. "Utilities and system operators need dependable tools to accurately predict voltage stability margins in order to come up with mitigation plans."
Voltage stability assessment (VSA) is important in helping power system operators anticipate potential system-wide instability problems. Although computer simulation tools are available to help monitor and control system voltage stability, their accuracy depends primarily on computer modeling of generation, load, and transmission facilities.
"As transmission networks operate closer to their limits, maintaining voltage stability is more important than ever," said Arshad Mansoor, vice president for power delivery and utilization at EPRI. "During conditions of high transmission loading or a power system disturbance, progressive drops in voltage can jeopardize system integrity. If the voltage drops were not corrected, voltage instability could lead to voltage collapse and wide-area blackouts. Having the capability to assess the stability margins online is an important step in improving reliability."
"The results of the validation study have shown us here at Entergy that this is promising for enhancing the security of our transmission system," says Sujit Mandal, senior staff engineer at Entergy.
Mansoor also said that this research has established a solid technical foundation for the next steps in the technology's development-demonstration and validation at the control center level and implementation as an online tool.
About EPRI
The Electric Power Research Institute, Inc. (EPRI, www.epri.com) conducts research and development relating to the generation, delivery and use of electricity for the benefit of the public. An independent, nonprofit organization, EPRI brings together experts from academia and industry as well as its own scientists and engineers to help address challenges in electricity generation, delivery and use, including health, safety and the environment. EPRI's members represent more than 90 percent of the electricity generated and delivered in the United States, and international participation extends to 40 countries. EPRI's principal offices and laboratories are located in Palo Alto, Calif.; Charlotte, N.C.; Knoxville, Tenn.; and Lenox, Mass.
