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 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.

Protection devices prevent damage to synchronous generators during loss-of-field events. In various embodiments, a first protective element is associated with a first protection zone to protect a generator from a loss-of-field event at full load. A second protective element is associated with a second protection zone to prevent thermal overload during underexcited operation of the generator and to protect from loss-of-filed at light load. A third protective element associated with a third protection zone limits operation of the generator within the generator's specific steady-state stability limits. A fourth protective element is associated with a fourth protection zone to provide an alarm prior to operation of the second protective element. In various embodiments, characteristics and limits of each of the protective elements are defined in the same plane (specifically, the P-Q plane) to simplify settings and allow for visualization of the element characteristics and the generator capability curve at one or more temperatures or cooling capacities.

A method for operating a permanent magnet electric machine of an engine includes determining a fault condition of the permanent magnet electric machine; and reducing a magnetism of one or more permanent magnets of the permanent magnet electric machine by increasing a temperature of the one or more permanent magnets in response to determining the fault condition of the permanent magnet electric machine.

An electronic device, in particular an alternator regulator, comprising a power stage to be connected to an inductive load, in particular to an alternator inductor, comprising at least one first pair of power transistors connected to a terminal of a DC bus, and a control circuit for said transistors, the transistors being disposed in parallel between said terminal of the DC bus and a first output to be connected to the load, at least one flyback diode connecting the opposite terminal of the DC bus to the first output, the control circuit being designed to generate a pulsed control signal for regulating the current in the load and for detecting a failure of one of the transistors, the control circuit being designed, during normal operation, to send the control signal to one of the transistors of the first pair, while maintaining the other transistor of said pair in an off-state.

A vehicle, e.g., an off-road vehicle, may include an internal combustion engine, a starter motor coupled to the engine via a multi-stage transmission during a starting process, a further electric machine coupled to a crankshaft of the engine, and a converter arranged to supply at least one energy storage unit, e.g., a battery. The converter may be configured as a 4-quadrant regulator having a B6 circuit of MOSFETs.

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.

The present invention relates to a circuit arrangement having an active rectifier circuit, in particular on a secondary side of an inductive energy transmission path. The circuit arrangement has a half or full bridge of power transistors for rectifying an AC voltage induced in an input inductor of the circuit arrangement. The power transistors are connected to the input inductor in such a way that an auxiliary voltage is split off from the induced AC voltage for switching the power transistors. As a result, even large currents, which result in a low output voltage, can be transmitted without endangering the operation of the rectifier circuit.

In an active converter that is connected to an electric machine, in which arresting circuits for activating a voltage arrest beginning at a first point in time are provided, and which is also configured for activating a load shedding reaction only when activation conditions are fulfilled beginning at a second point in time, the activation conditions include determining that the voltage arrest is still activated at the second point in time, that a voltage potential has not yet fallen below the first threshold value, and/or that a value that indicates a current flowing through at least one phase connection is above a third threshold value.

In an active converter that is connected to an electric machine, in which arresting circuits for activating a voltage arrest beginning at a first point in time are provided, and which is also configured for activating a load shedding reaction only when activation conditions are fulfilled beginning at a second point in time, the activation conditions include determining that the voltage arrest is still activated at the second point in time, that a voltage potential has not yet fallen below the first threshold value, and/or that a value that indicates a current flowing through at least one phase connection is above a third threshold value.