POWER UTILITIES’ TRANSMISSION SYSTEMS BENEFIT FROM AUTOMATING WIDE AREA COORDINATION REVIEW OF PROTECTIVE RELAYING DEVICES
Electrocon International has pioneered an innovative methodology to automate the wide area coordination review of a utility’s protective devices. Automation has made this clearly desirable objective both practical and affordable, where previously it was an ideal that even fully-staffed protection groups could not achieve. The transmission utility does not need to have Electrocon’s CAPE software and relay database in place, since the technique can be applied to data converted from almost any existing electronic network format, including those of Siemens’ PSS/E and ASPEN’s OneLiner.
This leading-edge approach has been proven by Electrocon’s customer Red Eléctrica de España in Madrid, Spain. REE’s experience is documented in their 2007 Western Protective Relay Conference Technical Paper, “Protection Coordination in the Transmission System and Boundaries – A Wide Area Coordination Study.” The paper details the process and benefits of automating the execution of the required studies and reporting, and is available from Electrocon International.
The new methodology uses the existing network model as a basis to verify coordination among backup protection devices throughout a high-voltage transmission system. Studies may involve many different types of operating conditions and potential network outages. The variety of conditions, faults, and protective devices which may need to be studied are one of the factors that has made this type of study impractical using manual techniques. Using a sophisticated macro to effectively supervise and conduct the entire study, the process results in a high-level summary report (one line of text per fault condition). The summary report simplifies the essential human work of analyzing the results of the study.
With clear summary reports, protection engineers can understand the results of wide area studies faster.
Potential applications of this methodology are not limited to utilities who already have their network modeled using Electrocon’s CAPE software. Almost any network data in electronic format, when updated and supplemented with protection data under this project, allows the automation of the entire coordination review and reporting process.
Benefits of this approach over traditional methods:
- Confident delivery dates. Using traditional manual techniques, internal staff or outside consulting firms could not be expected to conduct this type of study in a predictable time period without very high staffing levels and costs. Under automation, an appealing delivery date can be assured.
- Lower cost. Traditionally, the labor-intensive portions of the project are the fault studies, coordination evaluation, and preparation of the reports. Attempted manually, this type of project can require so much time and expense that it has been dismissed as impractical. The automated approach changes everything.
- Accurate. By automating the study, introduction of human mistakes through oversight or fatigue is prevented, no matter how large the scope of the study.
- Re-usable. If the utility has CAPE, its protection engineers can re-use the delivered techniques to repeat the review of selected or large areas as the system evolves.
"In addition to short circuit calculation, CAPE’s relay models allow us to perform wide area protection coordination studies. Those studies have been critical to improve the security of system protection and, therefore, to increase overall system reliability."
Santiago López Barba
Red Electrica de España
Overview of Wide Area Coordination Review
This brief document provides a look at the steps needed to set up your own Wide Area Coordination Review pilot project.
About Red Eléctrica de España’s Wide Area Coordination Study
Red Eléctrica de España, headquartered in Madrid, performed a wide area study of the entire Barcelona area in 2006. Electrocon provided technical support, including initial development of the macro that oversees the simulations and generates the reports. Of the 2,400 scenarios examined, 16% were found to have coordination problems for which REE was responsible. This number was reduced to 1% through follow-up to the study. More info: 2007 Western Protection Relay Conference technical paper, “Protection coordination in the transmission system and boundaries – a wide area coordination study.” Contact us to request the technical paper.
Red Eléctrica was the first company in the world devoted exclusively to electricity transmission and operation. Since its creation in 1985, it has been responsible for the transmission network and operation of the Spanish electricity system, leading the worldwide trend to see transmission as separate from generation and distribution. Red Eléctrica guarantees a balance between energy production and consumption, ensuring quality supply in all places and at all times and providing the market system with the safety and liquidity it needs.