A Comparative Study on the Impact of Different Grid Structures in Case of Electricity Interruption on Supply Continuity Indicators

Interruptions that occur as a result of faults in electricity grid cause significant losses both in economic and social areas. Turkish Energy Market Regulatory Authority (EMRA), the national regulatory authority, both prepares regulations on supply continuity, electricity quality and supervises the performance of electricity distribution companies by setting investment budgets in line with regulations. Distribution companies are making renewal investments to improve supply continuity in line with these regulations. Since a large investment covering the whole grid cannot be economically viable, accurate investment decisions can only be made with detailed analyzes to get best results with limited resources. Although, it is known that investments made to change grid topology significantly increase the supply continuity performance, due to operation difficulties such as protection coordination, the grid is still being operated radially. In this study, protection coordination applications for different grid structures are applied with the aid of a grid analysis software. Thus, it is shown that a sample distribution grid that located in Turkey can be operated with different topologies without protection coordination problems. Then appropriate grid topologies for various load groups are obtained by examining the supply continuity parameters, taking into consideration cleanliness of faults, isolation, maintenance and re-energization times.