9 luty 2016

Tavrida Electric REC25 application project in Bosnia and Herzegovina

Elektrokrajina (ZP Elektrokrajina a.d.) is the biggest electricity distribution company in Bosnia and Herzegovina. In the year 2014 the utility has launched a new full-scale project to increase reliability of the overhead lines, which have a high fault ratio. The project included the installation of automatic circuit reclosers in order to reduce the number of power interruptions and provide the network automation.
In cooperation with KER-Engineering (Russia) – regional partner in Bosnia and Herzegovina, Tavrida Electric supplied first two Rec25 reclosers to the electrical utility. The first phase of the pilot project was completed in July 2014 when Tavrida Electric and KER-Engineering specialists carried out a survey to identify the end-user actual reasons for modernization. In contrast to the traditional approach followed by other OEMs, Tavrida Electric main goal was to offer a complete technical solution for the particular application in a network. This method embraced a full set of procedures starting from the case study and ending with the supervision of installation and commissioning on site. The following project execution plan was adopted by the utility:

Stage 1:

  • Preliminary network analysis;
  • Collecting initial site data (source characteristics, upstream/downstream protection devices parameters and protection settings, load type and capacities);
  • Creating the network model in TELARM™ software based on the provided data;
  • Conducting a simulation, which allows utility engineers to evaluate the overall performance of the network calculate reliability indices; calculate fault and nominal currents/voltages in different sections of the network and verify the coordination between upstream and downstream protection devices;
  • Choosing the most suitable place for recloser installation based on the results of simulation and calculations;
  • Calculating the protection settings based on the results of simulation with the help of specially developed calculation algorithm;
  • Results evaluation and preparation of the technical documentation (case study results, explanatory note and guidance on the protection philosophy used for this project);
  • Presentation of the technical solution;
  • Utility approval.

Stage 2:

  • Manufacturing according to the customer requirements; Programming of reclosers;
  • Routine testing in accordance with IEEE C37.60/IEC 62271-111 and functional testing with the help of in-house protection relay test equipment;
  • Configuring and testing of communication equipment for remote communication.

Stage 3:

  • Shipping of the programmed and tested device to the customer;

Stage 4:

  • Customer training;
  • Installation and commissioning activities supervision on site.

Following the project approach, KER engineers visited Bosnia for the inspection on site and preliminary discussions with the end-user. The collaborative team presented the advantages of Rec25 and overall benefits of using automatic circuit reclosers for the utility networks. The electrical utility welcomed such an approach with enthusiasm as they did not have much experience of utilizing auto reclosers in the network and had difficulties with protection coordination. As the utility did not have a SCADA system at the level of 20 kV, Tavrida Electric proposed to integrate all reclosers into the Tavrida SCADA system via TELARM Dispatcher Interface™ (TDI).

Within one month Tavrida Electric protection engineers collected all required information about the network and protection philosophy currently followed by the utility. As a result of this study, the technical offer was presented to Elektrokrajina. The document included a technical study of the network including as follows:

  • Current protection coordination problems and recommendations;
  • Calculation of nominal and fault modes (currents, voltages, loads etc.);
  • Calculation of reliability coefficients before and after installation (SAIDI, SAIFI, MAIFI);
  • Proposed protection philosophy;
  • Calculation of protection settings;
  • Technical specification of the recloser and applicable components; Installation and application guide for each particular case;
  • Network models prepared with the help of TELARM™ software.

The technical offer was conveyed to the utility for approval. In September 2014, two Rec25 were installed in the area surrounding Banja Luka, the second largest city in Bosnia and Herzegovina. The delivery of equipment followed by the installation supervision and several training sessions for utility servicemen and engineers carried out by KER-Engineering specialists.

After the installation, the two reclosers were integrated into the Tavrida TDI SCADA system which provides a simple visualization and full remote control over the Rec25 protection devices from the utility dispatching center.

This pilot project is expected to be completed within the next 6 months. During this time, Elektrokrajina will analyze the feasibility of using the automatic circuit reclosers in the network. Based on the evaluation and performance report they will determine the way of further development in partnership with KER-Engineering and Tavrida Electric.