Hybrid Locomotive Research Articles

HYBRID LOCOMOTIVES OVERVIEW OF CONSTRUCTION SOLUTIONS

Nowadays, transportation becomes a significant source, apart from factories and power plants, of air pollution. Therefore, due to legal restrictions on the emission of noxious gases, other power sources for vehicles are necessary. Some of these power sources allow replacement of the internal combustion engine completely, whereas the other ones only support the engine operation. Hence, a hybrid powertrain – alternative to the drivetrain equipped with an internal combustion engine only – is increasingly being used. The hybrid powertrain was mostly applied in cars and buses but recently it has been also used in railway vehicles such as locomotives and multiple units. The paper presents a shortened and brief overview of construction solutions of selected hybrid locomotives. A list of the applied hybrid drive systems as well as the basic data and properties are provided. The most important variants of vehicles are compared. The presented material allows identification of the development trends in the considered area. The hybrid locomotive usually uses an onboard rechargeable energy storage system, placed between the power source and the traction transmission system connected to the wheelsets. Modification of a classic diesel-electric locomotives is a relatively simple procedure since they have all the components of a series hybrid transmission except the storage battery. Therefore, the existing and operated diesel-electric locomotives can be modified to increase their efficiency and reduce operating costs and emissions.

Double resonant isolated converter for battery charger with fast switching semiconductors used in hybrid electric shunting locomotive

This paper presents the study and experimental validation of a 9kW lead-acid battery charger used to feed the 72V DC-Bus inside a hybrid electric locomotive demonstrator realized in the frame of the French research project PLATHEE (energy-efficient and environmentally friendly train platform). The role of the converter is to supply the 72V DC consumers and charge the battery. The proposed topology for the battery charger is a DC/AC/DC step-down converter structure using high frequency transformer and double resonant series-parallel dipole. Main advantages of this topology are losses minimization due to soft switching operation, reduction of passive component weight and easy system integration. However, development and testing of the converter remain complex owing to high frequency constraints. Anti-parallel diodes of DC/AC half-bridge dissipate losses in excess during switching sequences and their reverse recovery energy leads to constraining high current peaks. A solution consists in using fast Insulated Gate Bipolar Transistor (IGBT)/diode technology well suited to high frequency switching, and able to limit diode peak-current amplitude during switch-off. Electro-thermal endurance tests have been performed in order to characterize the thermal behavior of the semiconductor module and control its case temperature raising. The battery charger working has been first validated on laboratory test-bench using a battery emulator, and then implemented in the hybrid locomotive for electrical couplings tests.

Energetic Macroscopic Representation of a Naturally-Aspirated Engine coupled to a salient pole synchronous machine

Hybrid Electric Vehicle (HEV) is considered as the most promising solution to overcome energy crisis and air pollution. To insure an improvement of the vehicle performance and a decrease of pollutant emissions, the design of its powertrain components is necessary. In a project of a hybrid locomotive, the studied railway powertrain admits a diesel engine as a primary source. In this paper, a dynamic model of a Naturally-Aspirated Engine using Energetic Macroscopic Representation (EMR) is presented. To deliver the produced mechanical power to a central Direct Current (DC) bus, a salient pole synchronous machine EMR model is also presented. From EMR models, the Maximum Control Structure (MCS) and then a Practical Control Structure (PCS) to locally control the diesel driven generator set are implemented. In addition to control the power delivered by the system, consumption and CO 2 gas emissions estimations are obtained from these models.

Design and modeling of power system for a fuel cell hybrid switcher locomotive

This paper discusses the design and modeling of power system for a fuel cell hybrid locomotive. Different types of fuel cells for appropriate application to locomotives were compared, fuel cell and auxiliary storage devices were modeled, and a control strategy for the overall system was developed in this paper. By using the proposed control strategy, the power control system regulates the sharing of power demand between fuel cell and auxiliary storage units including batteries and ultracapacitors. Experimental data of the power duty cycle of a typical switcher locomotive is analyzed. The proposed control system is tested using the experimental data. Results show that the control system is able to maintain output voltage from different power sources within a certain range, keep the state of charge of the batteries within an optimal range and meet power demand of the locomotive at a high efficiency.

Sizing and Energy Management of a Hybrid Locomotive Based on Flywheel and Accumulators

The French National Railways Company (SNCF) is interested in the design of a hybrid locomotive based on various storage devices (accumulator, flywheel, and ultracapacitor) and fed by a diesel generator. This paper particularly deals with the integration of a flywheel device as a storage element with a reduced-power diesel generator and accumulators on the hybrid locomotive. First, a power flow model of energy-storage elements (flywheel and accumulator) is developed to achieve the design of the whole traction system. Then, two energy-management strategies based on a frequency approach are proposed. The first strategy led us to a bad exploitation of the flywheel, whereas the second strategy provides an optimal sizing of the storage device. Finally, a comparative study of the proposed structure with a flywheel and the existing structure of the locomotive (diesel generator, accumulators, and ultracapacitors) is presented.

System design of a large fuel cell hybrid locomotive

Fuel cell power for locomotives combines the environmental benefits of a catenary-electric locomotive with the higher overall energy efficiency and lower infrastructure costs of a diesel-electric. A North American consortium, a public–private partnership, is developing a prototype hydrogen-fueled fuel cell-battery hybrid switcher locomotive for urban and military-base rail applications. Switcher locomotives are used in rail yards for assembling and disassembling trains and moving trains from one point to another. At 127 tonnes (280,000 lb), continuous power of 250 kW from its (proton exchange membrane) PEM fuel cell prime mover, and transient power well in excess of 1 MW, the hybrid locomotive will be the heaviest and most powerful fuel cell land vehicle yet. This fast-paced project calls for completion of the vehicle itself near the end of 2007. Several technical challenges not found in the development of smaller vehicles arise when designing and developing such a large fuel cell vehicle. Weight, center of gravity, packaging, and safety were design factors leading to, among other features, the roof location of the lightweight 350 bar compressed hydrogen storage system. Harsh operating conditions, especially shock loads during coupling to railcars, require component mounting systems capable of absorbing high energy. Vehicle scale-up by increasing mass, density, or power presents new challenges primarily related to issues of system layout, hydrogen storage, heat transfer, and shock loads.

Growing ozone hole "hangover" | California looks at tackling indoor air quality | Less-polluting hybrid locomotive begins operation | Earth's energy imbalance | Goldman environmental prizes awarded | Buying with the environment in mind | Does the EU need a new agency?

Growing ozone hole "hangover" | California looks at tackling indoor air quality | Less-polluting hybrid locomotive begins operation | Earth's energy imbalance | Goldman environmental prizes awarded | Buying with the environment in mind | Does the EU need a new agency?

Diesel's rational heat motor

Hybrid Electric Vehicle (HEV) is considered as the most promising solution to overcome energy crisis and air pollution. To insure an improvement of the vehicle performance and a decrease of pollutant emissions, the design of its powertrain components is necessary. In a project of a hybrid locomotive, the studied railway powertrain admits a diesel engine as a primary source. In this paper, a dynamic model of a Naturally-Aspirated Engine using Energetic Macroscopic Representation (EMR) is presented. To deliver the produced mechanical power to a central Direct Current (DC) bus, a salient pole synchronous machine EMR model is also presented. From EMR models, the Maximum Control Structure (MCS) and then a Practical Control Structure (PCS) to locally control the diesel driven generator set are implemented. In addition to control the power delivered by the system, consumption and CO2 gas emissions estimations are obtained from these models.