A trim head drive is provided. The trim head drive includes a nonlinear power supply. The nonlinear power supply includes an output and a return connected to a trim coil of a generator. An output of the nonlinear power supply directly drives a trim coil to control an output frequency of the generator. The nonlinear power supply varies the output positively and negatively to either sink or source a trim head current to control an output frequency of the generator.

A trim head drive is provided. The trim head drive includes a nonlinear power supply. The nonlinear power supply includes an output and a return connected to a trim coil of a generator. An output of the nonlinear power supply directly drives a trim coil to control an output frequency of the generator. The nonlinear power supply varies the output positively and negatively to either sink or source a trim head current to control an output frequency of the generator.

A converter system includes a DC bus for each phase of an input AC power signal; a first switching cell for each phase, including first two active switches coupled in series across the DC bus and forming a first switching cell AC pole therebetween, the first switching cell AC pole being coupled to a respective phase; and a second switching cell for each phase, including second two active switches coupled in series across the DC bus and forming a second switching cell AC pole therebetween. The second switching cell AC poles are coupled to each other to form a flying neutral. One of the first switching cell and the second switching cell switches at a frequency at least an order of magnitude greater than the line frequency. The other of the first switching cell and the second switching cell switches at a frequency approximately equal to the line frequency.

A converter system includes a DC bus for each phase of an input AC power signal; a first switching cell for each phase, including first two active switches coupled in series across the DC bus and forming a first switching cell AC pole therebetween, the first switching cell AC pole being coupled to a respective phase; and a second switching cell for each phase, including second two active switches coupled in series across the DC bus and forming a second switching cell AC pole therebetween. The second switching cell AC poles are coupled to each other to form a flying neutral. One of the first switching cell and the second switching cell switches at a frequency at least an order of magnitude greater than the line frequency. The other of the first switching cell and the second switching cell switches at a frequency approximately equal to the line frequency.

A trim head drive is provided. The trim head drive includes a nonlinear power supply. The nonlinear power supply includes an output and a return connected to a trim coil of a generator. An output of the nonlinear power supply directly drives a trim coil to control an output frequency of the generator. The nonlinear power supply varies the output positively and negatively to either sink or source a trim head current to control an output frequency of the generator.

A trim head drive is provided. The trim head drive includes a nonlinear power supply. The nonlinear power supply includes an output and a return connected to a trim coil of a generator. An output of the nonlinear power supply directly drives a trim coil to control an output frequency of the generator. The nonlinear power supply varies the output positively and negatively to either sink or source a trim head current to control an output frequency of the generator.

A circuit for converting single phase power to three phase power and method of operation that automatically starts upon detection of a demand for three phase power from a three phase load connected to the circuit.

A converter, a first switch, a second switch, and an inverter are disposed in that order along a second direction, at a first position in a first direction. A reactor and a capacitor are disposed in that order along the second direction, at a second position in the first direction. Energy is stored in the reactor via the first switch. The capacitor is discharged via the second switch. At least one of a set of the reactor and the converter and a set of the capacitor and the inverter is disposed side by side along the first direction.

An apparatus, such as a motor drive or other power converter, includes a first controller circuit coupled to at least one serial communications channel and configured to transmit at least one serial communications signal including drive signals and at least one second controller circuit configured to receive the transmitted at least one serial communications, to recover the drive signals therefrom and to transmit the recovered drive signals on respective ones of a plurality of parallel channels to at least one driver circuit that drives semiconductor switches of a power converter. The first controller circuit may be included in a first module, the at least one second controller circuit may be included in at least one second module, and the at least one serial communications channel may include at least one cable (e.g. a fiber optic cable) connecting the first module to the at least one second module.

A converter system includes a DC bus for each phase of an input AC power signal; a first switching cell for each phase, including first two active switches coupled in series across the DC bus and forming a first switching cell AC pole therebetween, the first switching cell AC pole being coupled to a respective phase; and a second switching cell for each phase, including second two active switches coupled in series across the DC bus and forming a second switching cell AC pole therebetween. The second switching cell AC poles are coupled to each other to form a flying neutral. One of the first switching cell and the second switching cell switches at a frequency at least an order of magnitude greater than the line frequency. The other of the first switching cell and the second switching cell switches at a frequency approximately equal to the line frequency.