Abstract: A system and method for assessing a health and functionality of a locomotive friction modifying system wherein the locomotive has a friction modifying applicator associated with a wheel of the locomotive for applying a friction modifying agent to a rail on which the wheel is traversing. The system and method comprise a sensor detecting a predetermined operational condition of the locomotive. The system and method also comprise a controller associated with the sensor and responsive to input from the sensor determining a per unit creep of an axle of the locomotive. The controller also determines a tractive effort of the axle of the locomotive and determines a friction modifying applicator state for the applicator associated with the axle.

Abstract: A system for isolating electrical ground faults and secondary failures in an electrical system, the system comprising an AC ground isolation state machine for detecting and isolating an AC ground, a DC ground isolation state machine for detecting and isolating a DC ground, a component failure isolation state machine for detecting and isolating a change in a resistance, and a component failure early detection algorithm for determining a failure before using the state machines.

Abstract: A method of dynamically controlling traction of a locomotive (V) having a plurality of axles (A1–A6) on each of which are mounted wheels (W) for moving the locomotive over a set of rails (R). A creep control signal (creep_n) is provided to a controller (TMTC) for each axle to move the locomotive over the rails, the creep control signal being a function of adhesion operation characteristics (tractive effort, torque, creep) for that axle. An advisory signal (ccc_n) combining values representative of the adhesion quality of the two axles is provided to the controller to maximize the tractive effort of the axle if the adhesion quality of the other axle is a maximum for the current rail conditions. This reduces the amount of time for the axle to attain its maximum tractive effort when rail conditions change.

Abstract: A method for detecting electrical faulty conditions in a plurality of power devices of a propulsion system is provided. The plurality of power devices is connectable in parallel circuit through a direct current (DC) link to an external DC power source. The method provides a first sequence of actions for determining an electrical short condition in at least one of the power devices upon the power source being connected. The method further provides a second sequence of actions for determining an electrical open condition in a respective one of the plurality of power devices during the occurrence of high current events.

Abstract: A multi-level system for management of a railway system and its operational components in which the railway system has a first level configured to optimize an operation within the first level that includes first level operational parameters which define operational characteristics and data of the first level, and a second level configured to optimize an operation within the second level that includes second level operational parameters which define the operational characteristic and data of the second level. The first level provides the second level with the first level operational parameters, and the second level provides the first level with the second level operational parameters, such that optimizing the operation within the first level and optimizing the operation within the second level are each a function of optimizing a system optimization parameter. The levels can include a railroad infrastructure level, a track network level, a train level, a consist level and a locomotive level.

Abstract: A system and method for assessing a health and functionality of a locomotive friction modifying system wherein the locomotive has a friction modifying applicator associated with a wheel of the locomotive for applying a friction modifying agent to a rail on which the wheel is traversing. The system and method comprise a sensor detecting a predetermined operational condition of the locomotive. The system and method also comprise a controller associated with the sensor and responsive to input from the sensor determining a per unit creep of an axle of the locomotive. The controller also determines a tractive effort of the axle of the locomotive and determines a friction modifying applicator state for the applicator associated with the axle.

Abstract: A system for isolating electrical ground faults and secondary failures in an electrical system, the system comprising an AC ground isolation state machine for detecting and isolating an AC ground, a DC ground isolation state machine for detecting and isolating a DC ground, a component failure isolation state machine for detecting and isolating a change in a resistance, and a component failure early detection algorithm for determining a failure before using the state machines.

Abstract: Method and system for determining a reference speed indicative of true ground speed of a vehicle having a plurality of axles are provided. The reference speed for a designated one of the axles is dynamically adjusted to account for changes in vehicular acceleration that may occur while determination of the reference speed is being performed. The method allows collecting a stream of samples over respective sampling intervals of at least one motion-indication parameter corresponding to a respective axle of the vehicle. In one aspect thereof, one may use a torque reduction rulebase configured to avoid high torque reduction, and inaccuracies in the motion-indication parameter due to high levels of creep, if any, in a wheel of the respective axle. The method further allows estimating an inertia value for the vehicle based on respective changes in tractive effort and acceleration over each sampling interval.

Abstract: A method for detecting electrical faulty conditions in a plurality of power devices of a propulsion system is provided. The plurality of power devices is connectable in parallel circuit through a direct current (DC) link to an external DC power source. The method provides a first sequence of actions for determining an electrical short condition in at least one of the power devices upon the power source being connected. The method further provides a second sequence of actions for determining an electrical open condition in a respective one of the plurality of power devices during the occurrence of high current events.

Abstract: A method and system for predicting malfunctions in a power inverter having one or more legs connected between first and second voltage buses is provided. Each leg has respective first and second controllable switches coupled in series to one another. The method allows for applying predetermined respective voltages at the first and second buses. The method further allows for selectively actuating the first and second switches between respective conductive or non-conductive states.

Abstract: An adhesion control system for a locomotive is provided for achieving and maintaining a maximum adhesion value.

Abstract: A method and traction control system for an AC locomotive which separately controls the allowable creep level of each individual axle and optimizes traction performance by minimizing torsional vibration per axle. The traction control system includes a torque maximizer and a torsional vibration detector. The torque maximizer evaluates the change in traction system performance levels and actual creep level of individual axles and determines the desired torque maximizer state for maximizing traction performance of each individual axle. The torque maximizer utilizes digital filtering to minimize control cycle time. The torsional vibration detector digitally processes estimated torque feedback of each traction motor in order to detect an unacceptable level of torsional vibration. The outputs of the torque maximizer and the torsional vibration detector are provided to a creep modulator which processes these inputs in order to control the operating creep level of each locomotive axle.

Abstract: A speed control system for an AC electric locomotive of the type having a plurality of wheel-axle sets with each wheel-axle set being coupled to an independently controllable AC electric traction motor and each motor having a corresponding speed sensor, each speed sensor providing a pair of signals which are resolvable to determine the speed and direction of rotation of the associated motor rotor, wherein the control system is arranged for maintaining torque control during failure of one of the signals from an associated speed sensor. The system detects the presence of each of the pair of signals from each speed sensor and responds to detection of only one of the pair of signals from one of the speed sensors for setting motor speed in response to the detected one of the signals. Direction is then determined by using signals from another of the speed sensors.

Abstract: A method and apparatus for generating gating signals for each of a plurality of electric switching devices in electric power conversion circuit includes a microcomputer for computing timing data representative of a relative time for application of gating signals to each of the switching devices for generating a desired electric power output from the conversion circuit. The timing data is provided to a volatile memory which has a plurality of addressable memory locations in which each memory location address corresponds to a selected time increment. Timing signals are generated in an address format for the memory such that each of the timing signals addresses a unique memory location in the memory. The gating signals for the switching devices are stored in memory locations in the memory corresponding to the time with respect to a starting point at which it is desired to have the gating signals generated.

Abstract: A monitoring system for an electrical power control system having a plurality of electrical components operable in electrically conductive and non-conductive states in response to command signals from a system controller. The controller is connected for receiving status signals indicative of the conductive and non-conductive states of selected ones of the electrical components. The monitoring system develops variable frequency electrical signals representative of preselected conditions of preselected ones of the electrical components, combines the variable frequency electrical signals with the status signals, and transmits the combined signals to the system controller. The system controller extracts the variable frequency electrical signals from the combined signals for determining the state of the preselected conditions.

Abstract: A method for inhibiting wheel slip in an electric alternating current induction motor powered vehicle responsive to a frequency command signal and to a signal representative of actual motor torque for establishing a corresponding excitation frequency for the induction motor develops the frequency command signal from a torque command signal. The method compares the torque command signal to selectively variable relatively positive and negative torque command limits to develop a torque reference signal. The magnitude of the signal corresponding to actual motor torque is subtracted from the magnitude of the torque reference signal to develop a torque error signal, which error signal is then converted to a corresponding torque regulator signal. The torque regulator signal is summed with the torque reference signal to develop a motor torque signal and the motor torque signal is then converted to a corresponding frequency command signal.

Abstract: A snubber circuit for limiting an initial voltage applied to a semiconductor switching device during transition of the switching device from a conducting to a non-conducting state includes a first circuit having a serially connected first diode and first capacitor coupled in parallel with the switching device and a second circuit having a second capacitor having a second capacitor connected between a cathode terminal of the switching device and a voltage potential less than a potential switched through the switching device and further having a second diode and a serially connected inductor coupled between the anode terminal of the switching device and the lower voltage potential. The voltage appearing at the cathode terminal of the switching device in excess of the lower voltage potential will effect a current through the inductor to limit an initial voltage rise at the cathode terminal when switching the device to a non-conducting state.

Abstract: A device in which a processor controls a desired frequency and a desired instantaneous angle of a pattern generation circuit. The processor also controls a desired amplitude of the system. The pattern generation circuit includes a ROM having firing data for only a portion of the angles for which the circuit produces output. Output for the angles stored in the PROM and for the remaining angles is generated using the partial data from the PROM. The processor selects the desired voltage levels of the motor output, and can instantaneously set an angle of the output.

Abstract: A dynamic braking grid arrangement for reducing EMI generated by dynamic or partial regenerative electrical braking of an electric traction motor powered vehicle coupled to a wayside power source by a third rail or catenary. The grid arrangement comprises a high-power dissipation resistance grid having a plurality of separately defined resistance elements, each having a generally elongate configuration. Mounting means support each of the grid elements adjacent to and parallel with each other of the elements. A plurality of electrical conduction devices connect the elements into an electrical circuit such that current passes through at least one element in a first direction and through at least one adjacent element in a second opposite direction such that EMI generated by any one element is substantially cancelled by EMI generated by an adjacent element.

Abstract: Apparatus and method for auto-self testing of a power converter and motor system wherein the power converter has three parallel legs, each including two series connected gate-turn-off thyristors (GTO) connected between a pair of DC power source buses. A microprocessor controls the test sequence in which each GTO is individually turned on in a predetermined order so as to create a transient snubber current through the motor and through each GTO when it is turned on. The snubber current and a voltage in each leg is measured and compared to a respective reference to detect wiring errors, and defects in the motor, the GTOs, and other system components. Error messages are generated in response to detection of abnormalities or defects.