Evaluation on the application mode of distributed generation

A distributed generation system (DGS) consists of a cluster of DG (photovoltaic, diesel engines, wind-power, fuel cells, micro-turbines), has many advantages in improving the quality of voltage in rural power grid and solving power supply in remote area or rural areas. The paper investigates a number of practical projects application modes and put forward several different DGS application modes, such as grid-connected DGS, grid-disconnected DGS, micro-grid system, and then analyses the characteristic of these DGs application modes. A complete index system for evaluation of the DGS application mode is established, the influence factors of capacity rate of DG in DGS and interaction among factors belonging different indices are analyzed. According to the specific need, the Analytical Hierarchy Process (AHP) is led in to perform comprehensive quantified analysis on the indices and the weights of these indices are determined, a comprehensive quantified model for application modes of the DG is built. Compare with traditional quantified method, the model considers the different characteristics of power grid and increases the DGS operating mode. Usually, there are three operating modes DGS in power grid, such as grid connected DGS, grid off DGS, microgrid system. The grid connected DGS and grid disconnect DGS have only one operation strategy respectively, microgrid system has two different operating modes. The microgrid system can operate in parallel to the grid or can operate in island, so its reliability is higher, it could connect or disconnect from power grid intentionally and smoothly. To obtain more accurate application scheme, the proposed model includes many constraints such as grid construction, economical efficiency, reliability, operation strategy and so on. Actually, the operation strategy of DGS application mode is analyzed by using the comprehensive qualified model, and rational analysis results are attained, thus the effectiveness and feasibility of the prop- sed model are verified. Finally, this paper comes up with a typical type of DGS application mode for different fields respectively.