A voltage regulator for a generator having a dynamic voltage-to-frequency (V/F) ratio includes a memory, a voltage calculator, and a selection module. The memory is configured to store a plurality of voltage-frequency curves for the generator. The voltage calculator is configured to receive data indicative of an output of the generator and configured to determine a resistance value from the output of the generator and a voltage value from the output of the generator. The selection module configured to select a voltage-frequency curve from the plurality of voltage-frequency curves in response to the resistance value and configured to select a voltage-frequency ratio from the selected voltage-frequency curve in response to the voltage value. An output adjustment for the generator is determined in response to the selected voltage-frequency ratio.

Control of an AC motor includes rotation over an operating speed range with the output from an inverter by operating the inverter at switching frequencies that vary in proportion to rotor speed. The operating speed range is parsed into a plurality of speed regions and the switching frequencies within each operating speed region may correspond to a respective pulse ratio that is different from the respective pulse ratio corresponding to an adjacent speed region.

Control of an AC motor includes rotation over an operating speed range with the output from an inverter by operating the inverter at switching frequencies that vary in proportion to rotor speed. The operating speed range is parsed into a plurality of speed regions and the switching frequencies within each operating speed region may correspond to a respective pulse ratio that is different from the respective pulse ratio corresponding to an adjacent speed region.

A method of controlling a power converter, connected to an electrical grid, to mimic a synchronous generator, by: determining a frequency control error with respect to a setpoint and actual frequency of the grid, determining an input power to an inertia model of a synchronous generator based on the frequency control error, regulating by means of the input power a rotational frequency of the inertia model, determining a voltage control error with respect to a setpoint and actual voltage, determining an exciter parameter of a synchronous generator model based on the voltage control error, regulating by means of the exciter parameter an output voltage of the synchronous generator model, adjusting the rotational frequency or a phase angle obtained from the rotational frequency, and the output voltage based on a virtual impedance of a stator of the synchronous generator model, and controlling the power converter based on the adjusted rotational frequency or the adjusted phase angle and on the adjusted output voltage.

A method of controlling a power converter, connected to an electrical grid, to mimic a synchronous generator, by: determining a frequency control error with respect to a setpoint and actual frequency of the grid, determining an input power to an inertia model of a synchronous generator based on the frequency control error, regulating by means of the input power a rotational frequency of the inertia model, determining a voltage control error with respect to a setpoint and actual voltage, determining an exciter parameter of a synchronous generator model based on the voltage control error, regulating by means of the exciter parameter an output voltage of the synchronous generator model, adjusting the rotational frequency or a phase angle obtained from the rotational frequency, and the output voltage based on a virtual impedance of a stator of the synchronous generator model, and controlling the power converter based on the adjusted rotational frequency or the adjusted phase angle and on the adjusted output voltage.

A variable-frequency generator set integrated system driven by an internal combustion engine includes a permanent magnet generator and an inverter device. The winding coils on the permanent magnet generator stator are all three-phase winding coils. The inverter device has an AC-DC rectification and voltage stabilization unit, a DC-AC variable-frequency inverter unit, a DC-DC conversion unit, and a control unit. The AC-DC rectification and voltage stabilization unit has an input end, a first output end, and a second output end respectively connected with the three-phase winding coils, the DC-AC variable-frequency inverter unit, and the DC-DC conversion unit. The DC-DC conversion unit is configured to convert a DC power source rectified by the AC-DC rectification and stabilization unit to a plurality of DC power sources with different voltages to supply power to the control unit and directly output. The permanent magnet generator is smaller in volume and weight and lower in cost.

A system for controlling electrical power generated by a permanent magnet machine coupled to an internal combustion engine includes a central processing unit configured to determine speed of the machine, and compare the machine speed with a predetermined range of machine speeds, a series power switching circuit connected between the machine and a battery, a bus decoupling power switch connected between a voltage bus and the battery, and a bridge switching circuit connected between the voltage bus and the machine and configured to amplify voltage generated by the machine if the machine speed is less than a predetermined value or fall within a predetermined range thereby charging the battery with amplified voltage even at lower machine speeds. The central processing unit selectively connects the bridge switching circuit with the battery by actuating the bus decoupling switch and/or the series power switching circuit depending upon the machine speed.

A method of monitoring a first winding set and at least one second winding set of a stator of a generator during operation is provided. The method includes: obtaining a first strength of a second harmonic of a first power produced from the first winding set; obtaining a second strength of a second harmonic of a second power produced from the second winding set; diagnosing the first winding set and/or the second winding set based on a second harmonic power difference between the first strength and the second strength.

A method of monitoring a first winding set and at least one second winding set of a stator of a generator during operation is provided. The method includes: obtaining a first strength of a second harmonic of a first power produced from the first winding set; obtaining a second strength of a second harmonic of a second power produced from the second winding set; diagnosing the first winding set and/or the second winding set based on a second harmonic power difference between the first strength and the second strength.

A system includes a generator control unit (GCU). The GCU includes a saturable reactor and a rectifier. Each of the saturable reactor and the rectifier has a separate input to receive AC power from a separate respective permanent magnet generator (PMG). A method includes supplying AC power from a first permanent magnet generator (PMG) of a generator to a saturable reactor of a generator control unit (GCU) that is operatively connected to control the generator. The method includes supplying AC power from a second PMG to a rectifier of the GCU, wherein the first PMG supplies a lower AC voltage to the saturable reactor than the second PMG supplies to the rectifier.