Improvement of Decision Support Methods for Restoration in Earthquake-Damaged Medium Voltage Electrical Distribution Networks

Project Coordinator: Assoc. Prof. Dr. Murat Göl

Project Team: Asst. Prof. Dr. Ebru Aydin Göl (METU-CENG), Asst. Prof. Dr. Burcu Güldür Erkal (Hacettepe U.-Civil Eng.)

Project Type: TUBITAK 1001 Scientific and Technological Research Projects Funding Program

With the developing technology, the continuity of the electric energy has gained the utmost importance. Critical customers (hospitals, critical government departments, military units, large industrial establishments, etc.) who need electrical energy to maintain their operations in the event of a possible disaster need to be energized as soon as possible. This project aims to evaluate the disaster scenarios such as earthquakes and to develop a decision support method for the rapid elimination of the hazard related problems that may occur in the electricity distribution system.

Restoring the power distribution systems after the interruption is a problem that researchers have been working on for a long time. Especially with the developing communication technology, decision support activities in this area have improved considerably, however, restoration strategies after an event of a serious hazard still have a serious research potential. The main difference that separates disruptions from operational faults or disruptions in an event of a hazard is the changes that occur in the network structure. After a major hazard some components in the network (electric poles, distribution transformers, etc.) may become unusable, and above all the current status of these components may be unknown. In other words, the system operator may have limited knowledge about the topology of the network that is desired to be restored after an earthquake. In this project, a decision support method that helps the system operator to restore the earthquake damaged network with uncertain network topology will be developed. In this way, the energy will be delivered to the critical customers in the shortest time, the duration of the diesel generator usage will be minimized and more reliable and continuous energization will be ensured.

Critical system elements (power plant, power line, transformer center, etc.) will be evaluated for a probable earthquake situation and dynamic performance analysis will be performed in order to predict the post-earthquake response of these elements. With these analytical methods, the probability of these elements to remain usable after an earthquake will be determined. Thus, a procedure for performance evaluation will be established. The developed procedure will work online and will calculate the most realistic outcomes using the information of the location and severity of the earthquake. This information is foreseen to be received from the data servers of the observatories and the earthquake research centers via internet in real time.

A decision support method based on the Markov Decision Process that uses the failure probabilities obtained after the performed structural analysis will be developed within the scope of the project. This developed method works in real time to provide optimum decision support to the system operator. It will also recommend a strategy for restoration, which is constantly updated with the information received from the field (notifications, aerial imagery, feedback from teams, etc.). The improved decision support method will aim to restore the network smoothly by taking the electrical characteristics of the network into account.

Distributed production units, which are becoming more widespread in medium voltage distribution systems, will be evaluated by the developed decision support method. The ability of conventional production facilities to operate as micro-networks in terms of minimizing the restoration time will also be evaluated by this decision support method.