An alternator for generating electrical power to one or more components of a power network includes a machine portion including a stator, a rotor and a rectifier, a battery connection terminal connected to the machine portion and configured to be connected to a battery, and an isolation device integral to the alternator. The isolation device is located on an electrical path between at least the machine portion and the battery connection terminal, and the isolation device is configured to isolate at least one of the alternator and another component of the power network from receiving electric current from the battery based on an undesirable condition occurring in the power network.

A secondary magnetic excitation generator-motor device that inputs a first ignition pulse command to a three-level NPC power converter such that a detected excitation current value corresponds with an excitation current command value, the secondary magnetic excitation generator-motor device having a function of identifying a first phase, a second phase, or a third phase in descending order of a current absolute value, wherein a pulse switch to output an ignition pulse command to the three-level NPC power converter switches the ignition pulse command to the second ignition pulse command when a current absolute value exceeds a set overcurrent level 1, and switches the ignition pulse command to the first ignition pulse command when current absolute values for three phases are all equal to or smaller than a set overcurrent level 2.

A secondary magnetic excitation generator-motor device that inputs a first ignition pulse command to a three-level NPC power converter such that a detected excitation current value corresponds with an excitation current command value, the secondary magnetic excitation generator-motor device having a function of identifying a first phase, a second phase, or a third phase in descending order of a current absolute value, wherein a pulse switch to output an ignition pulse command to the three-level NPC power converter switches the ignition pulse command to the second ignition pulse command when a current absolute value exceeds a set overcurrent level 1, and switches the ignition pulse command to the first ignition pulse command when current absolute values for three phases are all equal to or smaller than a set overcurrent level 2.

An installation for generating a three-phase AC voltage to be fed into a power supply system, having a transformer connected to a three-phase generator on the output side to convert a first three-phase AC voltage into a second three-phase AC voltage having a second voltage level, which is lower than a first voltage level and a first frequency, and having a frequency converter connected to the transformer on the output side to supply a rotor winding with a third three-phase AC voltage to convert the second three-phase AC voltage into the third three-phase AC voltage having the second voltage level and a second frequency which is lower than the first frequency, wherein the frequency converter is designed such that the second frequency corresponds to a difference between a mains frequency of the power supply system and the first frequency.

An installation for generating a three-phase AC voltage to be fed into a power supply system, having a transformer connected to a three-phase generator on the output side to convert a first three-phase AC voltage into a second three-phase AC voltage having a second voltage level, which is lower than a first voltage level and a first frequency, and having a frequency converter connected to the transformer on the output side to supply a rotor winding with a third three-phase AC voltage to convert the second three-phase AC voltage into the third three-phase AC voltage having the second voltage level and a second frequency which is lower than the first frequency, wherein the frequency converter is designed such that the second frequency corresponds to a difference between a mains frequency of the power supply system and the first frequency.

The generator is the only product of its kind that has the capability of turning a generator head via the power of a drive rather than a motor. The generator is uniquely designed with an advanced sensor technology that sends a signal to the selected outlet of the generator. This unprecedented product is crafted with strong, sturdy materials to ensure sustainability and durability and can be used in a wide variety of settings.

The generator is the only product of its kind that has the capability of turning a generator head via the power of a drive rather than a motor. The generator is uniquely designed with an advanced sensor technology that sends a signal to the selected outlet of the generator. This unprecedented product is crafted with strong, sturdy materials to ensure sustainability and durability and can be used in a wide variety of settings.

A field winding synchronous machine drive system includes a field winding synchronous machine having a stator and a rotor and a drive apparatus configured to drive the field winding synchronous machine. The stator has N m-phase stator coils wound on a stator core to create a rotating magnetic field, where N is an integer not less than 2 and m is an integer not less than 3. The rotor has at least one main field winding wound on a rotor core to create field magnetic flux. The drive apparatus includes N inverters each of which supplies m-phase alternating current to a corresponding one of the N m-phase stator coils. Specifically, each of the inverters supplies the corresponding m-phase stator coil with the m-phase alternating current which includes a fundamental-wave current and a time-harmonic current superimposed on the fundamental-wave current; the time-harmonic current has a shorter period than the fundamental-wave current.

A field winding synchronous machine drive system includes a field winding synchronous machine having a stator and a rotor and a drive apparatus configured to drive the field winding synchronous machine. The stator has N m-phase stator coils wound on a stator core to create a rotating magnetic field, where N is an integer not less than 2 and m is an integer not less than 3. The rotor has at least one main field winding wound on a rotor core to create field magnetic flux. The drive apparatus includes N inverters each of which supplies m-phase alternating current to a corresponding one of the N m-phase stator coils. Specifically, each of the inverters supplies the corresponding m-phase stator coil with the m-phase alternating current which includes a fundamental-wave current and a time-harmonic current superimposed on the fundamental-wave current; the time-harmonic current has a shorter period than the fundamental-wave current.

A voltage difference is determined between the observed voltage and a reference direct current bus voltage. A quadrature-axis (q-axis) voltage command is outputted based on a current difference derived from the voltage difference. A commanded direct-axis (d-axis) voltage is determined based on a measured d-axis current and a determined d-axis reference current derived from a mathematical relationship between d-axis residual voltage, the observed voltage and the commanded q-axis voltage, where residual voltage is proportional to a function of the observed voltage and the commanded q-axis voltage. An inverse Parks transformation module or a data processor provides one or more phase voltage command based on inverse Parks transform of the commanded voltages.