A permanent magnet machine with a hybrid cage and methods for operating same are disclosed. According to one aspect, the subject matter described herein includes a rotor and hybrid cage for an electrical machine, the rotor comprising a rotor body having a central axis and including a plurality of permanent magnets positioned to create a plurality of rotor magnetic poles distributed around a peripheral surface of the rotor. The rotor also includes a hybrid cage that includes conductive loops around each of the rotor magnetic poles, where the conductive loops are controllable to form a closed circuit or an open circuit around each of the rotor magnetic poles. A closed circuit may be created when a magnetic field having a field strength or change of field strength that exceeds a threshold magnitude is present, such as during a fault condition, and an open circuit may be created when a magnetic field having a field strength or change of field strength that exceeds a threshold magnitude is not present, such as during normal operation.

A rotor of line start permanent magnet synchronous motor is provided. The rotor includes bars of cage windings. The rotor includes an additional inductance coupled to the cage windings and located on a first end of the bars. The rotor includes an end ring located on a second end of the bars. The additional inductance provides a reactance to reduce a starting current during an asynchronous starting of the line start permanent magnet synchronous motor.

A rotor of line start permanent magnet synchronous motor is provided. The rotor includes bars of cage windings. The rotor includes an additional inductance coupled to the cage windings and located on a first end of the bars. The rotor includes an end ring located on a second end of the bars. The additional inductance provides a reactance to reduce a starting current during an asynchronous starting of the line start permanent magnet synchronous motor.

A rotor for a synchronous reluctance machine including a rotor core having a plurality of magnetically conductive laminations stacked in a rotor axial direction. The magnetically conductive laminations include cut-out portions forming a plurality of flux barriers radially alternated by flux paths portions, at least one of the flux barriers including a bridge connecting two flux paths portions adjacent to the at least one flux barrier. The at least one flux barrier has a first, barrier, mid-line which is the line that is equidistant from both sides of the at least one flux barrier, and the bridge has a second, bridge, mid-line which is the line that is equidistant from both sides of the bridge, the first and second mid-lines intersecting at an intersection point. The bridge has a first symmetry axis and a second symmetry axis and is non-symmetrical with respect to at least one of the first and second symmetry axis. The first symmetry axis is defined as the straight line tangential to the first, barrier, mid-line and passing through the intersection point, and the second symmetry axis is defined as the straight line orthogonal to the first symmetry axis and passing through the intersection point.

A rotor for a synchronous reluctance machine including a rotor core having a plurality of magnetically conductive laminations stacked in a rotor axial direction. The magnetically conductive laminations include cut-out portions forming a plurality of flux barriers radially alternated by flux paths portions, at least one of the flux barriers including a bridge connecting two flux paths portions adjacent to the at least one flux barrier. The at least one flux barrier has a first, barrier, mid-line which is the line that is equidistant from both sides of the at least one flux barrier, and the bridge has a second, bridge, mid-line which is the line that is equidistant from both sides of the bridge, the first and second mid-lines intersecting at an intersection point. The bridge has a first symmetry axis and a second symmetry axis and is non-symmetrical with respect to at least one of the first and second symmetry axis. The first symmetry axis is defined as the straight line tangential to the first, barrier, mid-line and passing through the intersection point, and the second symmetry axis is defined as the straight line orthogonal to the first symmetry axis and passing through the intersection point.

A rotor system for a downhole motor comprises a set of permanent magnets, a set of conductors and a pair of end conductor rings connecting the set of conductors. The set of permanent magnets and the set of conductors being substantially coaxial and having the substantially the same linear extent. The set of permanent magnets can be located radially inwards from the set of conductors, and may be provided by discrete conductive bars.

A rotor system for a downhole motor comprises a set of permanent magnets, a set of conductors and a pair of end conductor rings connecting the set of conductors. The set of permanent magnets and the set of conductors being substantially coaxial and having the substantially the same linear extent. The set of permanent magnets can be located radially inwards from the set of conductors, and may be provided by discrete conductive bars.

The present invention discloses an alternating current (AC) permanent magnet motor, including a stator, a rotor, and a controller. Cable troughs and some same coil windings exist on a silicon steel sheet of a stator core. Grooves exist on the stator core, and stator permanent magnets are mounted in the grooves. The groove includes two types of grooves, namely, open grooves and enclosed grooves, and the two types of grooves are alternately laminated to form the stator core. A coil unit of the stator includes stator permanent magnets mounted in grooves of two stator cores and four same coils, and some same coil units form a three-phase stator coil. The rotor includes rotor cores, enclosed squirrel cages and rotor permanent magnets. The controller outputs a three-phase power source having a same positive and negative half sine-wave or step-wave pulse.

A rotor system for a downhole motor includes at least one permanent magnet rotor section, and at least one squirrel cage rotor section. The permanent magnet rotor section and the squirrel cage rotor section are joined in series by a connection. In one example the connection includes a male self lock taper on one rotor, and a corresponding female self lock taper on the other rotor.

A rotor system for a downhole motor includes at least one permanent magnet rotor section, and at least one squirrel cage rotor section. The permanent magnet rotor section and the squirrel cage rotor section are joined in series by a connection. In one example the connection includes a male self lock taper on one rotor, and a corresponding female self lock taper on the other rotor.