Investigation of Train Dynamics in Passing Through Curves Using a Full Model

In this article a train model is developed for studying train derailment in passing through bends. The model is three dimensional, nonlinear, and considers 43 degrees of freedom for each wagon. All nonlinear characteristics of suspension elements as well as flexibilities of wagon body and bogie frame, and the effect of coupler forces are included in the model. The equations of motion for the train are solved numerically for different train conditions. A neural network was constructed as an element in solution loop for determination of wheel-rail contact geometry. Derailment factor was calculated for each case. The results are presented and show the major role of coupler forces on possible train derailment.

CCS: A Railway Corridor Control System Utilizing Ultra Wideband Radio Technology

Ultra Wide Band (UWB) radio is a unique technology which combines a megabit wireless local area network with a centimeter-resolution radiolocation (RADAR) capability over distances less than 100 meters. A linear chain of UWB nodes can be used to create a hop-by-hop data transmission network, which also forms a RADAR “corridor” along the chain. By co-locating such a chain of nodes along a railroad right-of-way, precise information on the location and velocity of trains could be distributed throughout the corridor. In addition, the radar corridor would detect the introduction of track obstacles such as rocks, people, and automobiles, as well as shifted loads and other high-wide train defects. Finally, the network of nodes would enable off-train communications with payload sensors, locomotive computers, and could also provide wireless connectivity for passenger service.

A Dynamic Stiffness and Damping Model for Rail Car Center Plate Polymer Liners

The center plate interface is made up of the body plate attached to the car body bolster, the polymer liner, and the bolster bowl, which is a part of the truck bolster. Roll motion of the rail car leads to the car body bolster rolling over the polymer liner on the truck bolster, which may result in partial loss of contact of the body plate with the polymer liner. This nonlinear phenomenon has a deleterious impact on the rail car dynamics. A technique for creating a center plate dynamic model accounting for the polymer liner and the loss of contact condition is presented here. Material tests were performed to model the stress-relaxation of the liner. A stiffness/damping model of the center plate accounting for the nonlinear effects of the lift-off was developed based on a nonlinear Winkler foundation model and was tested for a one-degree-of-freedom dynamic model. This continuous model was adapted into a 16 stiffness-damping element model to enable its usage in a NUCARS™ rail-car dynamic model.

Determination of Traction Power Distribution System Impedances and Susceptances for AC Railroad Electrification Systems

Electrical characteristics of the traction electrification system, together with the train power demand, headway, and operating scenario, are the key factors in determining the overall system performance. A mathematical procedure for calculation of traction power distribution system line impedances and capacitances is developed using the Alternative Transient Program (ATP). The technique is applied to Direct Feed and Autotransformer Feed traction electrification systems and typical results for one-, two-, three-, and four-track railroads are presented. All self-and mutual impedance and capacitance components are included in the calculations.

Linear Synchronous Motor Propulsion of Small Transit Vehicles

The Linear Synchronous Motor (LSM) has been used for several high speed maglev applications but only recently have developers applied it to urban transit. MagneMotion has worked with the Federal Transit Administration (FTA), as part of their Urban Maglev Project, to develop an LSM propelled maglev transit system called M3. The top speed is only half that of the Transrapid maglev trains now operational in China but by using small vehicles with short headway and rapid acceleration it is possible to achieve outstanding performance at much lower cost. The combination of LSM technology and small vehicles is a cost effective replacement for rotary motor and Linear Induction Motor (LIM) powered trains for all transit applications, including conventional rail and monorail. LSM is the enabling technology that makes it economically and technically feasible to achieve high capacity with short vehicles and, conversely, the use of small vehicles makes LSM propulsion economically attractive. Small vehicles operating with short headway and organized in clusters can achieve high capacity without offline loading. Very precise position sensing and guideway based propulsion and control make short headways safe and affordable. This paper describes the objectives of the MagneMotion LSM development, discusses some of the design features, and presents 3 examples. The examples are based on operational speeds up to 60 m/s (134 mph), accelerations up to 0.16 g, vehicle headways down to 4 seconds, and capacities up to 12,000 passengers per hour per direction (pphpd). Examples include a 1 mile high capacity shuttle, a 4 km unidirectional loop with several stations, and a 30 km high-speed airport connector. Calculations show that an LSM propelled transit system has lower capital cost than conventional transit systems using vehicle-based electric propulsion with either rotary motors or LIMs. Vehicles are simplified, the cost of energy and maintenance is reduced and, most important, users of the transit system experience major reductions in trip times.

Hardware-Software Structure for On-Line Power Quality Assessment: Part I

The main objective of the proposed work is to introduce a new concept of advanced power quality assessment. The introduced system is implemented using applications of a set of powerful software algorithms and a digital signal processor based hardware data acquisition system. The suggested scheme is mainly to construct a system for real time detection and identification of different types of power quality disturbances that produce a sudden change in the power quality levels. Moreover, a new mitigation technique through generating feedback correction signals for disturbance compensation is addressed. The performance of the suggested system is tested and verified through real test examples. The obtained results reveal that, the introduced system detects fast and accurately most of the power quality disturbance events and introduces new indicative factors estimating the performance of any supply system subjected to a set number of disturbance events.

Suspension Dynamics and Design Optimization of a High Speed Railway Vehicle

The design of suspension systems for high speed railway vehicles involves the simultaneous consideration of those requirements as suspension packaging, ride quality, stability, and cost. A design strategy is presented in this paper that enables an optimal design with respect to these competing requirements. The design strategy consists of four steps including the development of a lumped parameter vehicle model, the determination of vehicle parameters, the formulation of a design objective, and the minimization of the objective to optimize key suspension parameters. The design objective captures vehicle requirements including ride quality, suspension packaging, and wheel/rail holding. Power spectral densities (PSDs) are computed for the vertical vehicle body acceleration, suspension travel and dynamic wheel/rail interaction. The design objective function is calculated based on these PSDs and minimized to yield an optimum. An example suspension design is proposed that improves vehicle ride quality and wheel/rail holding without sacrificing other requirements.

The Hi-Lo Bi-Track System

The Hi-Lo Bi-Track System is an innovative technology that provides appropriate superelevations on curves to suit both high-speed passenger trains and low-speed freight trains. Adoption of the Hi-Lo Bi-Track System would provide the following benefits: • Permit creation of high-speed lines for passenger trains over existing freight train rights-of-way without compromising performance of either train technology. • Provide improvement in typical train trip times due to reduced need for speed reduction at curves. • Provide savings in energy consumption due to less braking for curves and subsequent acceleration back to line speed. • Provide better performance then “tilting trains” in reducing typical train trip times. • Avoid high vertical and lateral track forces resulting from operation of “tilting trains.” • Applicable to high-speed mail and express freight trains in addition to high-speed passenger trains.

Hybrid Technology for the Rail Industry

A new type of battery-dominant hybrid technology has been developed for the rail industry. Switcher locomotive service is characterized by highly variable power output use. This variability in demand is exploited to allow the use of a significantly smaller, fuel efficient, Tier 2 certified, low maintenance engine and generator combination to supply energy to the traction motors and to the application-engineered battery pack. In the last three years, a demonstrator vehicle, the Green Goat®, has been designed, tested, constructed and put into field trials for 18 months in various locations and types of service, with impressive (performance and operational) results. The design, concept, field trials results, as well as applications of the technology to other types of service, are discussed.

Advanced Light Rail Vehicle Communication Systems Design

The use of electronic subsystems to perform complex tasks has grown in the consumer goods and automotive sectors to such a degree that these capabilities have become commonplace, yet in the field of light rail vehicles, they have made relatively little impact. The technology exists today to provide greatly increased passenger safety, security and system operational efficiency by the judicious application of mature subsystem designs. Such systems include radio based, fully integrated vehicle management systems with GPS, silent alarm capability and passenger information control, external passenger door and coupler monitoring video cameras, forward facing video recording for accident investigations, interior video recording for reduction in vandalism, interior video cameras linked to Passenger to Operator Intercoms to provide the Operator with more information and the transfer of data to and from vehicles via wireless LAN. This paper will describe the application of these subsystems to the new Phoenix light rail vehicle and project what the future may hold.