Abstract: An electric power system includes an inverter device coupled with a motor. The inverter device receives from the motor electric energy generated by dynamic braking of the motor. An energy storage device is coupled with the inverter device, and a variable resistive component is disposed between the inverter device and the energy storage device. The variable resistive component controls a direction of conduction of the electric energy from the inverter device toward the energy storage device, a resistive grid, or a system load. The variable resistive component controls the direction of conduction of the electric energy from the inverter device based on a first amount of the electric energy conducted from the inverter device, a transfer rate of the electric energy conducted from the inverter device, or one or more characteristics of the energy storage device.

Abstract: A controller may control a transfer of electric energy between two or more energy storage devices of a plurality of energy storage devices, at least one energy storage device being disposed onboard a vehicle system, and identify a transfer restriction on the transfer. The controller may change a transfer characteristic based at least in part on the transfer restriction. A system may include a controller to monitor transfer of electric energy between one or more energy storage devices disposed onboard one or more vehicle systems and energy transfer substations that are offboard the one or more vehicle systems. A method may include controlling a transfer of electric energy between two or more energy storage devices, at least one energy storage device being disposed onboard a vehicle system, identifying a transfer restriction on the transfer, and changing a transfer characteristic based at least in part on the transfer restriction.

Abstract: A system includes a generator coupled to an engine and configured to generate electricity from rotational movement of a shaft of the engine, a motor configured to be driven by the generator through one or more power conversion components, the motor configured to drive a load, a sensor configured to measure generator output, and a controller configured to detect engine imbalance based on a frequency content of a signal output from the sensor in response to a contribution to the frequency content from the one or more power conversion components and/or the load of the motor being less than a threshold value.

Abstract: A method includes detecting an out of phase condition and an in-phase condition between a vehicle platform and two or more propulsion units attached to the platform. A first speed from a first propulsion unit is compared to a second speed and a torque of one or more propulsion units is controlled to reduce the out of phase condition and/or the in-phase condition when a difference between the first speed and the second speed is greater than a threshold value. A vehicle includes a platform, two or more propulsion units attached to the platform, and a processor. The processor compares a first speed from a first propulsion unit to a second speed, detects from the comparison an out of phase condition between the platform and the two or more propulsion units, and detects from the comparison an in-phase condition between the platform and the two or more propulsion units.

Abstract: A system is provided that may include plural converters that are connected to a common bus. Each of the converters may be configured to convert an alternating current (AC) through the common bus to a direct current (DC) by alternating switches of each of the plural converters between open and closed states in a switching cycle. The system may also include a controller circuit that may be configured to adjust the AC conducted onto the common bus to the plural converters so that a root mean square of a ripple current component of the AC meets one or more designated criteria.

Abstract: A system that may include, plural inverters connected to a common bus and at least one capacitor, the inverters configured to convert a direct current (DC) through the common bus to an alternating current (AC) by alternating different switches of the inverters between open and closed states in a respective switching cycle for each of the inverters, and a controller circuit configured to reduce a ripple current conducted onto the common bus to the inverters, by controlling the inverters to apply a frequency shift to the respective switching cycle of one or more of the inverters to spread a harmonic current spectrum along the common bus. The controller circuit is configured to apply the frequency shift to at least a first inverter and a second inverter of the plural inverters.

Abstract: A system includes a generator coupled to an engine and configured to generate electricity from rotational movement of a shaft of the engine, a motor configured to be driven by the generator through one or more power conversion components, the motor configured to drive a load, a sensor configured to measure generator output, and a controller configured to detect engine imbalance based on a frequency content of a signal output from the sensor in response to a contribution to the frequency content from the one or more power conversion components and/or the load of the motor being less than a threshold value.

Abstract: A system that may include, plural inverters connected to a common bus and at least one capacitor, the inverters configured to convert a direct current (DC) through the common bus to an alternating current (AC) by alternating different switches of the inverters between open and closed states in a respective switching cycle for each of the inverters, and a controller circuit configured to reduce a ripple current conducted onto the common bus to the inverters, by controlling the inverters to apply a frequency shift to the respective switching cycle of one or more of the inverters to spread a harmonic current spectrum along the common bus. The controller circuit is configured to apply the frequency shift to at least a first inverter and a second inverter of the plural inverters.

Abstract: A system includes a generator coupled to an engine and configured to generate electricity from rotational movement of a shaft of the engine, a sensor configured to measure one or more of a parameter of generator output, engine speed, or engine shaft torque, and a controller configured to detect engine imbalance based on a frequency content of a signal output from the sensor in response to a contribution to the frequency content from another component of the system being less than a threshold value.

Abstract: A locomotive control system measures actuating parameters of a locomotive propulsion system and monitors the actuating parameters according to a forcing function of operation of the propulsion system. A degraded component of the locomotive is identified by comparing actuating parameters generated according to the forcing function with actuating parameters expressed as a function of speed of another locomotive propulsion system, examining changes in the generated actuating parameters over time, examining oscillations in movement of the locomotive during gear shifting, comparing wheel speed decreases during another forcing function, and/or comparing a magnitude of a spectrum of the actuating parameters of with one or more designated magnitudes.

Abstract: The systems and methods described herein relate to electrical circuits. A system (e.g., inverter current system) is provided. The system includes plural inverters connected to a common bus and at least one capacitor. The inverters are configured to convert a direct current (DC) through the common bus to an alternating current (AC), by alternating different switches of the inverters between open and closed states in a respective switching cycle for each of the inverters. The system includes a controller circuit. The controller circuit is configured to adjust a current conducted onto the common bus to the inverters so that a root mean square of the current meets one or more designated criteria. The controller circuit controls the inverters to apply a frequency shift to the respective switching cycle of one or more of the inverters.

Abstract: The systems and methods described herein relate to electrical circuits. A system (e.g., inverter current system) is provided. The system includes plural inverters connected to a common bus and at least one capacitor. The inverters are configured to convert a direct current (DC) through the common bus to an alternating current (AC), by alternating different switches of the inverters between open and closed states in a respective switching cycle for each of the inverters. The system includes a controller circuit. The controller circuit is configured to adjust a current conducted onto the common bus to the inverters so that a root mean square of the current meets one or more designated criteria. The controller circuit controls the inverters to apply a frequency shift to the respective switching cycle of one or more of the inverters.

Abstract: A ripple current control system includes plural inverters connected to a common bus. The inverters are configured to convert a direct current (DC) through the common bus to an alternating current (AC) by alternating different switches of the inverters between open and closed states in a switching cycle for each of the inverters. The system also includes a controller configured to reduce a ripple current conducted onto the common bus by controlling the inverters to apply a phase shift to the switching cycle of one or more of the inverters based on the number of the inverters.

Abstract: A system includes a generator coupled to an engine and configured to generate electricity from rotational movement of a shaft of the engine, a sensor configured to measure one or more of a parameter of generator output, engine speed, or engine shaft torque, and a controller configured to detect engine imbalance based on a frequency content of a signal output from the sensor in response to a contribution to the frequency content from another component of the system being less than a threshold value.