The invention relates to a method for operating a rotating electric machine (1) having a rotor (3), a polyphase excitation winding (5) and a commutation apparatus (9) for commutating excitation winding currents of the excitation winding (5) depending on rotor position values (R) for rotor positions of the rotor (3). First measurement values (A) for the rotor positions are detected by means of a first sensor apparatus (13) and second measurement values (B) for the rotor positions are detected by means of a second sensor apparatus (15). For the commutation of the excitation winding currents, the rotor position values (R) are formed from weighted mean values (M) of the first measurement values (A) and the second measurement values (B). In a first rotation speed range of rotor rotation speeds of the rotor (3), the first sensor apparatus (13) has a higher resolution of the rotor positions than the second sensor apparatus (15) and, in the first rotation speed range, the first measurement values (A) are given more weight than the second measurement values (B) when forming the weighted mean values (M).

Provided is a method for controlling, by means of field-oriented closed-loop control, an active rectifier which is electrically connected to a stator of a generator of a wind turbine. The generator has a rotor which is mounted so as to be rotatable about the stator and comprises the steps of determining a mechanical position of the rotor with respect to the stator, predefining DC components of rotor-fixed d and q coordinates for at least one 3-phase stator current, determining an AC component for the q coordinate at least as a function of the mechanical position of the rotor, modulating the determined AC component of the q coordinate onto the predefined DC component of the q coordinate, so that a modulated q coordinate is produced which has a DC component and an AC component, and controlling the active rectifier at least as a function of the modulated q coordinate and preferably as a function of the d coordinate.

A power generation system for a drilling tool includes a turbine, an alternator, a converter and a first active rectifier control (ARC). The turbine is adapted to be driven by a fluid flow in a well. The alternator is coupled to the turbine and generates an alternative current (AC). The converter converts the AC to direct current (DC) and carries out active rectification. The first active rectifier control (ARC) controls the active rectification of the converter.

In an inverter generator having a generator unit including three phase windings driven by an engine, a converter having multiple switching elements and configured to convert alternating current outputted from the generator unit to direct current, an inverter configured to convert direct current outputted from the converter to alternating current and output the alternating current to a load, and a converter control unit configured to determine PWM control ON-time period and drive the multiple switching elements so that inter-terminal voltage of direct current outputted from the converter stays constant with respect to increase/decrease of the load, the converter control unit is configured to detect, with respect to voltage waveforms occurring in the three-phase windings in cycle (tn), crossing angle between voltage waveform of one phase and voltage waveform of a phase adjacent thereto and to drive the multiple switching elements of either the one phase and the adjacent phase in cycle (t) such that the detected crossing angle is included in the PWM control signal ON-time period.

A power system, including: a synchronous electrical generator having a rotor; and an angle computation unit configured to: determine a rotor angle in a steady state period of the synchronous electrical generator, determine a change in rotor angle in a transient period of the synchronous electrical generator, and estimate the rotor angle in the transient period based on the steady state rotor angle and the change in rotor angle.

A control system of a vehicle includes: an electric motor configured to phase rotation of an camshaft of an engine relative to rotation of a crankshaft of the engine; a current module configured to, while the engine is off: selectively transition a current signal back and forth between a first state and a second state; and a motor driver module configured to, while the engine is off: apply power to the electric motor from a battery and adjust a position of the camshaft toward a predetermined position when the current signal is in the first state; and disconnect the electric motor from the battery and allow the position of the camshaft to move away from the predetermined position when the current signal is in the second state.

A control system of a vehicle includes: an electric motor configured to phase rotation of an camshaft of an engine relative to rotation of a crankshaft of the engine; a current module configured to, while the engine is off: selectively transition a current signal back and forth between a first state and a second state; and a motor driver module configured to, while the engine is off: apply power to the electric motor from a battery and adjust a position of the camshaft toward a predetermined position when the current signal is in the first state; and disconnect the electric motor from the battery and allow the position of the camshaft to move away from the predetermined position when the current signal is in the second state.

A control system that includes a converter circuit and a control device is disclosed. The converter circuit may be configured to control a phase current of a switched reluctance machine. The control device may be configured to determine an estimated flux based on a bus voltage, a phase voltage, and a mutual voltage. The control device may be configured to determine a flux threshold based on the phase current, and determine a first limit and a second limit relative to the flux threshold. The first limit and the second limit may be scaled relative to the flux threshold based on one or more of the target speed, the load demand, or the bus voltage. The control device may be configured to compare the estimated flux with the first limit, and reset the estimated flux to the second limit based on determining that the estimated flux satisfies the first limit.

A circuit for calculating position and/or speed of a rotor of an electric generator, is provided. The circuit includes: an input port for receiving a vibration input signal representing a cogging torque of the electric generator, a speed observer module connected to the input port and generating a cogging position signal and a cogging frequency signal as outputs, a rotor speed module receiving the cogging position signal and the cogging frequency signal as inputs and generating a rotor position signal and a rotor speed signal as outputs.

In one embodiment, a generator includes a rotor configured to rotate in cooperation with a stator to generate electrical power. An exciter of the generator includes at least one circuit board, a stationary exciter stator, and a control circuit. The circuit board is mechanically coupled to a rotor of the generator and includes at least one coil of an electrical conductor. The stationary exciter stator is configured to induce a current in the at least one coil of the at least one circuit board. The control circuit is configured to modify the current from the at least one coil and provide the modified current to a field of the generator.