Microgrid planning in distribution system | |
| Author | Kitavit Buayai |
| Call Number | AIT Diss. no.ET-13-01 |
| Subject(s) | Microgrids (Smart power grids) Power generation planning |
| Note | A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | Microgrid (MG) is defined as a sub transmission or distribution system with a set of small distributed generation and loads. MG is a way forward for seamless integration of renewable distributed generation. MG can operate either stand alone or grid connected. To reap maximum benefits of the MG, the planning needs to be done in an optimal way. The development of MG systems poses technical challenges to distribution power system planning. Hence, the dissertation focuses on MG planning in a primary distribution system considering loss reduction, voltage profile improvement and minimum annualized investment cost. The thesis is organized in two parts. Part I provides a two-stage multi-objective MG planning methodology in a primary distribution system. In the first stage, the optimal region for MG is identified by the loss sensitivity factor. In the second stage, a methodology based on Pareto-based non-dominated sorting genetic algorithm II (NSGA-II) is proposed to determine locations and sizes of a specified number of distributed generation DG units within MG. A fuzzy logic based decision making analysis is used to obtain the final trade off solution. Moreover, steady state analysis is performed on the MG distribution system in grid connected or islanded mode. The proposed planning methodology is tested on two test distribution systems including 33-bus radial and 69-bus closed loop distribution systems. Test results indicate that NSGA-II is a viable planning tool for practical MG system and useful contribution of MG in improving distribution system performance. Part II presents an application of the two-stage multi-objective MG planning methodology in a practical primary distribution system within Provincial Electricity Authority (PEA), Zone 3, Nakhonratchasima Thailand. In the first stage, the optimal region for MG is identified by the loss sensitivity factor and land use suitability. The conceptual design of the novel integrated planning tool using distribution system load flow based Geographical Information System (GIS) are proposed. The computer-based (PC) framework combines the analytical capabilities of modern GIS and distribution system load flow for MG planning. The methodology is used for locating an optimal site for MG system. In the second stage, the methodology in Part I is applied to the specified distribution feeder in the study area. Test results indicate that georeferenced data manipulating capabilities of GIS made them suitable for planning and operation of distribution system with loss reduction benefit. In summary, the contribution of this dissertation is loss sensitivity factor which is effectively used for ranking and selecting a proper location of MG in a primary distribution network. A Pareto-based non-dominated sorting generic algorithm II (NSGA-II) is effectively used to determine optimal location and sizes of a specified number of distributed generator DG units within MG. In addition, a primary distribution system model in geographic information system (GIS) model is used to identify locations most suitable for considering MG region within a distribution system and various factors are incorporated such as environmental, social, economic and technical constraints. |
| Year | 2013 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Energy Technology (ET) |
| Chairperson(s) | Weerakorn Ongsakul;Mithulananthan, Nadarajah |
| Examination Committee(s) | Shrestha, Rajendra Prasad;Marpaung, Charles O. P.;Basal, Ramesh Chand |
| Scholarship Donor(s) | Rajamangala University of Technology Isan (RMUTI); |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 2013 |