A thyristor starter is configured to accelerate a synchronous machine from a stop state to a predetermined rotation speed by sequentially performing a first mode of performing commutation of an inverter by intermittently setting DC output current of a converter to zero and a second mode of performing commutation of the inverter by induced voltage of the synchronous machine. The thyristor starter is further configured to raise induced voltage in proportion to the rotation speed of the synchronous machine by keeping field current constant and to suppress rise of the induced voltage by reducing the field current after the induced voltage reaches a first voltage value, in the first mode.

The present disclosure relates to a circuit device for demagnetizing the rotor of an externally excited synchronous machine and to a method for operating the circuit device.

A rotating field machine (200) including a stator (140) and a rotor (150) are provided. In particular, a dual-winding rotating field machine (200) in which the stator (140) includes two separate windings can be provided. In one example implementation, the stator (140) can include an excitation winding (220) configured to control an excitation current and a power winding (230) configured to control power flow to an electrical system. The dual-winding rotating field machine (200) can further include a starting mode and a generating mode. During the starting mode, both the excitation winding (220) and the power winding (230) can be coupled to one or more switching power converters (170). During the generating mode, the power winding (230) can be coupled to a variable frequency bus and the power converter (170) can be used to manage excitation power only.

A field winding type rotating electric machine includes a stator and a rotor. The stator has a stator core and multiphase stator windings. The rotor has a rotor core, a main pole portion provided at predetermined intervals in a circumferential direction and protruding radially from the rotor core, and a field winding wound around the main pole portion. A plurality of magnetic poles having alternating polarities in the circumferential direction are formed by flowing a field current through a field winding. The stator winding is provided on a peripheral surface of the stator core on the rotor side in a radial direction. The stator core is not provided with teeth protruding radially from the stator core toward the rotor.

A field winding type rotating electric machine includes a stator and a rotor. The stator has a stator core and multiphase stator windings. The rotor has a rotor core, a main pole portion provided at predetermined intervals in a circumferential direction and protruding radially from the rotor core, and a field winding wound around the main pole portion. A plurality of magnetic poles having alternating polarities in the circumferential direction are formed by flowing a field current through a field winding. The stator winding is provided on a peripheral surface of the stator core on the rotor side in a radial direction. The stator core is not provided with teeth protruding radially from the stator core toward the rotor.

An excitation system (15) is disclosed for providing excitation to a main rotating electrical machine (2). The excitation system comprises an exciter (50) and an auxiliary generator (52). The exciter and the auxiliary generator have separate stator cores (14, 18) and share a common rotor core (16). The common rotor (16) core may be located between the two stator cores (14, 18). This may help to optimize space, improve material usage and reduce the total rotating mass. A mounting arrangement for the common rotor core is also disclosed.

An excitation system (15) is disclosed for providing excitation to a main rotating electrical machine (2). The excitation system comprises an exciter (50) and an auxiliary generator (52). The exciter and the auxiliary generator have separate stator cores (14, 18) and share a common rotor core (16). The common rotor (16) core may be located between the two stator cores (14, 18). This may help to optimize space, improve material usage and reduce the total rotating mass. A mounting arrangement for the common rotor core is also disclosed.

In a rotating electric machine, a stator includes a stator winding, a field winding includes a series-connection body including a plurality of winding portions, and a rotor includes main pole portions protruding from a rotor core in a radial direction. A harmonic current for inducing a field current in the field winding flows to the stator winding. A rectifying element is connected in series to the field winding, configures a closed circuit with the field winding, and rectifies the field current that flows to the field winding to flow in one direction. In a capacitor, a first end is connected to a connection point between adjacent winding portions and a second end is connected to either of both ends of the rectifying element. A partitioning portion is disposed between at least a single set of adjacent winding portions among the plurality of winding portions and includes a magnetic material.

A field coil type rotating electric machine includes a rotor where both a series resonant circuit including a first winding and a capacitor and a parallel resonant circuit including a second winding and the capacitor are formed. The first winding is radially located closer than the second winding to a stator. The capacitance of the capacitor and the ratio of the number of turns of the second winding to the number of turns of the first winding are set to have the amplitude of a total resultant magnetic flux lower than the amplitude of a field resultant magnetic flux. The total resultant magnetic flux is the resultant of the field resultant magnetic flux and magnetic flux generated by harmonic currents flowing in phase windings of a stator coil. The field resultant magnetic flux is the resultant of magnetic fluxes generated by harmonic currents flowing in the first and second windings.

An electrical synchronous machine is provided for a rail-free vehicle. The vehicle has drive wheels and the synchronous machine is designed to generate a torque, which propels the vehicle, at the drive wheels. The synchronous machine has a stator and a rotor which rotates around the stator, wherein the stator has a stator winding of at least three-phase construction for forming a rotating stator magnetic field, and wherein the rotor has at least one rotor winding which is designed for forming a rotor magnetic field. A method for at least partially circumferentially establishing a current-excited synchronous machine provides a rotor yoke, provides a large number of rotor poles, fastens the rotor poles to the rotor yoke for forming a rotor, provides a stator, and inserts the stator into the rotor.