Energy model for urban train transportation system

Paula Uribe

In order to perform an integral energy analysis for an urban train transportation system, four large scale systems and their interactions shall be considered: Trains, Tunnels (and exterior environment), Stations and Electrical Substations; each characterized by a set of parameters and mathematical relations that describe their operation in terms of energy consumption. The main aspects that influence the energy consumption of the system are trains technological characteristics, passenger load, speed profiles, electrical energy consumption (HVAC systems, lighting, signaling and auxiliaries) and overall performance. Important outputs of this analysis are the overall energy usage in different systems (total energy breakdown), the overall impact of a change in a subsystem on overall energy usage and the impact of technological changes in a system in overall performance. Different scenarios can be calculated and compared with this simulation tool, helping the decision makers when defining operational strategies and selecting innovative solutions.

Thermal impact of energy losses in an underground transportation system

Pablo Orellana

In this presentation a thermal model developed at CMM will be shown. This model analyses the thermal impact of energy losses in an underground transport system, as well as the thermal losses due to the number of passengers in transit. Also the model delivers a breakdown of the thermal losses in order to identify the most important factors that influence the temperature of the system. Also the humidity calculations will be shown, in order to asses effectively the passenger comfort on the subway stations.

Energy Optimal Control of Thermal Comfort in Trams

Raphael Hofstädter

In this presentation a thermal comfort control for trams is shown, which minimises the power consumption of the heating, air conditioning and ventilation system. The objective is to achieve a satisfying indoor climate in a tram with the smallest electrical effort possible, by using methods of control engineering and closely related sciences. First, mathematical models — based on the fundamental laws and balance laws of thermodynamics — of all thermally relevant components are stated. Individual components modelled are: Interior of the tram, the HVAC and the controller to calculate the temperature, relative humidity and carbon dioxide concentration in the interior of the tram. In the next step the numerical values of the parameters for the created models are estimated. This is exemplary explained for the heat capacity and the heat transfer coefficient of the vehicle. Then, a new controller is developed as cascaded controller based on the linearised models of the plant (interior of the tram and HVAC unit). The master control loop, whose controller is a model-predictive controller, regulates the thermal comfort inside the tram. The controller of the slave control loop is realised with a mixed-integer optimisation, which converts the set-point of the auxiliary control variable in an energy-optimal way. For the mixed-integer problem a heuristic solution is used. The algorithms were implemented on a rapid controller prototyping platform, tested during several climatic wind tunnel tests first and daily application is proven during on-site measurements since July 2013.

Integration of solar energy and energy management to rapid transport systems.

Marcelo Matus

The rapid urban transport system is known for its electric energy-intensive operation, with most of the energy demand coming from the electricity needed to provide traction power to trains. This presentation examines the potential for energy efficiency and integration of solar energy in the train operation and other electricity consumptions, such as lighting, air conditioning, etc. After performing a literature review of some international initiatives, a case study is developed to explore the application of the solutions in a real context based on the Metro of Santiago’s needs. The analysis also considers the design and simulation of a smart-grid solution integrating solar energy and energy storage systems.

This event is embedded in the 1st Workshop in Strategies for Solar Energy and Basic Sciences Research, that runs from January 23th to January 28th, 2014.