Optimal Operation of Electrified Railways with Renewable Sources and Storage

Abstract

This paper proposes an approach for the optimal operation of electrified railways by balancing energy flows among energy exchange with the traditional electrical grid, energy consumption by accelerating trains, energy production from decelerating trains, energy from renewable energy resources (RERs) such as wind and solar photovoltaic (PV) energy systems, and energy storage systems. The objective function considered in this work is the minimization of total operating cost of electrified railway system consisting of cost of power generation from the external power system, cost of power obtained from RERs such as wind and solar PV sources, cost of power from storage systems such as battery storage and supercapacitors, and the income obtained by selling excess power back to the main electrical grid. This problem is formulated as an AC optimal power flow problem subjected to various equality and inequality constraints. In this work, the probability distribution functions (PDFs) are used to the uncertainties related to wind and solar PV powers. The proposed optimization problem is solved by using CONOPT solver of generalized algebraic modeling system (GAMS) software, which is a powerful and efficient optimization tool. The simulation results obtained with GAMS/CONOPT solver are also compared with meta-heuristic based differential evolution algorithm (DEA).

Multistage Multiobjective Optimization for Optimal Energy Management of the Connected Cophase Traction Power System

“…However, the PQ issues are not considered in their model. Salkuti [36] presented an optimal operating model in which the uncertainty of RER and the total operating cost of the system are considered. However, the mutual impacts between the external grid and ERS and the PQ problems have been neglected.…”

“…Also, regarding the PQ problems, which could result in penalty charges for ERSs [12], the independence index of CCTPS has been introduced and considered as the second objective. erefore, unlike references [10,[34][35][36][37][38][39][40][41], the proposed model improves the independence of the CCTPS from the external grid because TSSs can exchange power and utilize the dispatchable resources of other TSSs. Moreover, compared to references [35][36][37][38][39], the three-phase VUR is taken into account, and unlike references [40,41], the VUR is considered as the third objective of the proposed model.…”

Deployment of Autonomous Trains in Rail Transportation: Current Trends and Existing Challenges

“…Furthermore, a comprehensive framework was developed for the AI applications in high-speed rail transportation, considering operational efficiency and customer comfort criteria. Along with the aforementioned efforts, many other studies applied various AI-based methods, optimization, simulation, and other operations research techniques to address different decision problems and issues that are related to train operations, including energy and power sources [80][81][82][83][84][85][86][87][88][89][90][91][92][93][94][95][96], train speed control and trajectory control [97][98][99][100][101][102][103][104][105][106], timetable synchronization and optimization [107][108][109][110][111][112][113][114][115][116][117], as well as intelligent maintenance and prognostics [118][119][120][121][122][123]…”

Optimal stochastic energy management of electrical railway systems considering renewable energy resources' uncertainties and interactions with utility grid

“…Although different methods have been developed for optimal operation of ERSs, the ERSs’ optimal stochastic energy management, including RERs, has received less attention. In a few references like, 19,20 the probabilistic impacts of RERs on ERSs have been studied. In Ref.…”

“…The changes in the number of passengers also have not been considered by Aguado et al 19 In Ref. 20, an optimal approach for renewable‐based ERSs for the operating cost minimization has been reported, which has also considered regenerative braking energy (RBE). The economic dispatch of the railway system using the RERs has been studied in Ref.…”