A chance constrained techno-economic analysis of using small scale power generation units for providing subways systems: Tabriz Urban Railway System

The need for diversified energy resources, sustainable development, energy security and improving the reliability of electrical energy systems, have led to serious global attention to the development and expansion of small-scale power plants better known as distributed generation (DG) and increase the share of these resources in the global energy basket. One of the problems for the power supply of subway systems, is that it is difficult to supply the energy they need using the utility grid due to their passage through crowded centers. This requires the construction of power posts by the company in charge of building the metro systems which requires a lot of costs for the company. Therefore, alternative ways of supplying energy for the metro system can be sought. One way is to use small-scale local power plants. The use of these energy sources can achieve benefits such as higher economic productivity, greater reliability and better management of fluctuations. Therefore, in this paper, the issue of using distributed energy sources for the metro system is examined. The proposed framework for effective and efficient resource development, along with long-term planning of the system components, management and intelligent use of these resources to provide the power supply of the subway, in the field of short-term operation also includes. Purchase prices from the upstream network have been considered and the net present value (NPV) and investment costs have been studied using engineering economics methods. The uncertainty of demand levels in traction buses are modeled using chance constrained programming (CCP). By means of CCP approach, better decisions without jeopardizing the security of the system, can be made. Finally, using GAMS and DigSilent softwares, the problem is optimized and the technical parameters are examined for practical Tabriz subway system test system.