An electric rotating machine having a stator and a rotor, wherein the rotor is provided with rotor windings connected to electric contacts to carry a field current. A control device is provided to adjust the field current carried by the rotor windings. At least one sensor is provided to give information about the temperature at the location of the at least one sensor. The at least one sensor is located on or embedded in the rotor windings, and the at least one sensor is connected to the control device such that the control device is able to read the information given by the at least one sensor. The control device is further arranged to adjust the field current carried by the rotor windings and/or power output or power input of the electric rotating machine based on the information given by the at least one sensor.

A method of classifying a stator winding fault in a brushless synchronous generator includes measuring an electrical parameter of the stator winding and classifying the fault by calculating positive or negative sequence harmonics of the parameter and comparing one or more harmonic component to a threshold.

A portable power generator with power monitor and control. The portable generator may include an alternator powered by an engine and configured to generate an alternator output, a first output receptacle coupled to the alternator output through a first switch, and a second output receptacle coupled to the alternator output through a second switch. The portable generator may further include a sensor unit configured to detect at least one output parameter of the first output receptacle. An electronic processor of the portable generator may be configured to receive first sensor signals indicating a measured quantity of the at least one output parameter of the first output receptacle and determine that the measured quantity exceeds a predetermined threshold. The processor may also be configured to disable the first output receptacle in response to determining that the measured quantity exceeds the predetermined threshold.

A technique for providing electric power to an electric power utility grid includes driving an electric power alternator coupled to the grid with a spark-ignited or direct injection internal combustion engine; detecting a change in electrical loading of the alternator; in response to the change, adjusting parameters of the engine and/or generator to adjust power provided by the engine. In one further forms of this technique, the adjusting of parameters for the engine includes retarding spark timing and/or interrupting the spark ignition; reducing or retarding direct injection timing or fuel amount and/or interrupting the direct injection; and/or the adjusting of parameters for the generator including increasing the field of the alternator or adding an electrical load.

The present disclosure provides a brushless direct current (BLDC) motor overload detection apparatus. The BLDC motor overload detection apparatus includes a measurer for measuring an electrical angle of the BLDC motor, a determiner for determining whether a difference between the electrical angle measured by the measurer and a mechanical angle of the BLDC motor, estimated through current supplied to the BLDC motor, is within a predetermined range, and a driving controller for control of driving of the BLDC motor according to whether the BLDC motor stalls, determined by the determiner.

A circuit for polarizing magnetic material using a magnetic field of an excitation coil includes a port configured to provide a connection with a DC power supply. The circuit also includes at least one capacitor and driver circuitry configured to drive the excitation coil and the at least one capacitor. The driver circuitry is configured to discharge the excitation coil to the DC power supply via the at least one capacitor.

A genset including at least one generator for generating electrical energy, which can be driven by a drive device is provided. Also provided is a detection device for detection of the presence of a grid fault in at least one phase of the power grid, a device for determining an operating state of the generator immediately before or upon detection of a grid fault, and a regulating device, to which the signals of the detection device and the device for determining an operating state of the generator can be fed. The regulating device is designed upon detection of a grid fault to reduce the power of the drive device in dependence of that operating state of the generator, which has been determined immediately before or upon detection of the grid fault.

A method of controlling a variable speed constant frequency (VSCF) power converter is provided. The method includes receiving a determination that a sensed AC current output has exceeded a predetermined limit. The AC current output is converted from a DC voltage and has a constant frequency. The DC voltage is converted from a variable frequency AC voltage. The variable frequency AC voltage is generated in response to a mechanical energy input having a varying parameter. The method further includes decreasing the DC voltage in response to a determination that the sensed AC current output has exceeded the predetermined limit.

A wind turbine includes a wind rotor, a generator, and a converter. The generated electric power is fed from the converter by means of a feed to a turbine transformer for delivery to a grid. The feed is designed as a double branch including a power-branched power circuit breaker unit having a first feed line and a second feed line connected in parallel, wherein a separate low-voltage winding of the turbine transformer and a separate power circuit breaker at the connector of the converter is associated with each feed line.

A DFIG power system defines a generator power path and a converter power path. The generator power path has a DFIG with a rotor and a stator. The converter power path has a power converter with a rotor-side converter coupled to a line-side converter via a DC link. The power converter has at least two power bridge circuits connected in parallel. A method of operating the DFIG power system includes monitoring, via one or more sensors, at least one electrical condition thereof. The method also includes comparing, via a control system, the at least one electrical condition to a predetermined threshold, the predetermined threshold being indicative of an occurrence of a transient overloading event. Further, the method includes alternating between non-interleaving and interleaving intervals if the at least one electrical condition exceeds the predetermined threshold so as to reduce harmonics of the DFIG power system.