Abstract: Systems and methods for pre-aligning rotors of synchronous motors on a synchronous AC grid prior to startup of the motors are provided. A partial power converter may provide an alignment current through an n-phase supply line to a synchronous AC motor. The synchronous AC motor may be configured to receive polyphase AC power through the n-phase supply line from the synchronous AC grid, whereas the partial power converter is powered by a power source isolated from the synchronous AC grid. The alignment current may cause a rotor of the synchronous AC motor to move to and stop at a target angular position.

Abstract: Methods and systems are provided to damp oscillations in a synchronous alternating current (AC) grid. Current may be received from the synchronous AC grid through a phase of an n-phase supply line. The current received from the synchronous AC grid is supplied to a phase of the synchronous motor. A sub-harmonic oscillation may be detected in the current received from the synchronous AC grid. The sub-harmonic oscillation may be damped by: shunting a portion of the current away from the phase of the synchronous motor during a first time period in an upper-half of the sub-harmonic oscillation, and/or supplying compensation current from a partial power converter to the phase of the synchronous motor during a second time period in a lower-half of the sub-harmonic oscillation.

Abstract: Methods and systems for load alignment assistance are provided. An alignment current may be provided with a partial power converter through an n-phase supply line to a synchronous alternating current (AC) motor during a startup of a synchronous AC grid. The synchronous AC motor may receive polyphase AC power through the n-phase supply line from the synchronous AC grid during the startup. The partial power converter may be powered by a power source isolated from the synchronous AC grid. The alignment current may be controlled such that the alignment current causes a rotor of the synchronous AC motor to align with a rotor of a generator that powers the synchronous AC grid.

Abstract: Systems and methods for pre-aligning rotors of synchronous motors on a synchronous AC grid prior to startup of the motors are provided. A partial power converter may provide an alignment current through an n-phase supply line to a synchronous AC motor. The synchronous AC motor may be configured to receive polyphase AC power through the n-phase supply line from the synchronous AC grid, whereas the partial power converter is powered by a power source isolated from the synchronous AC grid. The alignment current may cause a rotor of the synchronous AC motor to move to and stop at a target angular position.

Abstract: A power control system for providing power sharing is provided. An energy storage device is configured to supply a first portion of power of an electrical power as a total load power and an engine-driven electrical machine is configured to supply a second portion of power of the total load power. A power converter is electrically coupled to the energy storage device and the engine-driven electrical machine such that the power converter is configured to supply the total load power to an electrical load device. A controller is coupled to the power converter and the controller receives characteristic data from at least one of the energy storage device, the engine-driven electrical machine, and the electrical load device. Based on the received characteristic data, the controller determines a power sharing proportion of a power sharing amount of each of the first portion of power and the second portion of power of the total load power to be supplied via the power converter to the electrical load device.

Abstract: A system includes one or more synchronous generators mechanically coupled to an excitation system. The excitation system is configured to output an excitation signal to excite the synchronous generator to produce a voltage and a current at an output of the synchronous generator. During startup of the synchronous generator, the excitation system may also output pulses of the excitation signal to initiate synchronism of one or more non-rotating electric motors electrically coupled to the synchronous generator. In addition, the pulses may be output to urge rotation of the non-rotating electric motors into rotational electrical alignment with the synchronous generator and each other.

Abstract: A system includes one or more synchronous generators and one or more corresponding exciters. The exciter is configured to output a field current for exciting the synchronous generator to produce a voltage and a current at an output of the synchronous generator. The system may also include one or more electric motors electrically coupled to the synchronous generator and configured to drive one or more mechanical loads. A controller included in the system is configured to identify power angle oscillations between the voltage and the current and control an exciter voltage of the exciter to damp the identified power angle oscillations.

Abstract: A power system includes a bus, a first controller and one or more second controllers. The first controller is configured to excite a first generator to generate electric power on the bus in response to initiation of rotation of the first generator. The one or more second controllers are configured to excite one or more respective second generators with a constant excitation in response to initiation of rotation of the first generator. The second generator(s) are electrically coupled with the bus and configured to operate as a motor to commence synchronous rotation with the first generator in response to electric power being present on the bus. The second controller(s) are further configured to initiate dynamic adjustment of the excitation of the second generator(s) to generate electric power on the bus with the second generator(s) in response to the first generator and the second generator(s) synchronously reaching a predetermined rotational speed.

Abstract: A system includes an exciter configured to operate with a synchronous generator. The exciter may be mechanically coupled and rotatable with the synchronous generator, or the exciter may be independently rotatable. The exciter is configured to output a field current for exciting the synchronous generator to produce a voltage and a current at an output of the synchronous generator. The synchronous generator may be synchronized with loads during a time when the synchronous generator is at substantially zero speed and the loads, such as motors, are at zero speed. A controller included in the system is configured to control output of the field current by the exciter with an exciter voltage. The controller may control the exciter voltage to selective include an AC component and DC component in accordance with a rotational speed of the exciter.

Abstract: A system may include a prime mover configured to provide mechanical energy to the system by spinning a shaft. The system further includes a synchronous AC generator mechanically coupled to the shaft, and an exciter mechanically coupled to the shaft and configured to output a field current for exciting the synchronous AC generator. The system also includes a number of synchronous electric motors electrically coupled to the AC generator and configured to drive one or more mechanical loads. A controller of the system is configured to establish and maintain a magnetic coupling between the synchronous AC generator and the synchronous electric motors by controlling a level of the field current during a ramped increase in rotation of the synchronous AC generator from zero rotational speed. The motors accelerate synchronously with the generator due to the magnetic coupling as the rotational speed of the generator increases.