Abstract: The thermal management system for in-slot cooling of electric motors includes separating structures, either in the form of a scaffolding structure or a monolithic winding structure which is placed in between the adjacent winding turns to physically separate the winding turns to define coolant fluid passages for circulation of a coolant fluid in direct contact with the lateral surfaces of the winding turns. The scaffolding and monolithic winding structures are made from an electrically insulating material and are filled with a dielectric fluid that serves both the coolant and the electrical insulator between the winding turns. An end-winding organizer may be positioned at two end regions of each stator tooth to provide a curved surface for the winding turns to be held in tension throughout the 180° winding end turns and is formed with grooves to define the passage for the coolant flow to ensure that the flowing coolant reaches the surface of the innermost winding turns.

Abstract: An electrical machine includes a rotor, a stator, and a winding mounted within a housing. The rotor includes a rotor core mounted to a shaft and a plurality of blades extending radially away from the rotor core. Each blade of the plurality of blades is curved axially along the rotor core. The stator includes a stator core and a plurality of teeth extending from the stator core toward the rotor core to define a plurality of slots between successive teeth. The winding is wound through at least two slots of the plurality of slots. The stator is mounted radially relative to the rotor. The housing includes a front wall, a back wall, and a radial sidewall mounted between the front wall and the back wall to define an enclosure. A radial inlet aperture wall is formed circumferentially through the radial sidewall to form an opening through the radial sidewall.

Abstract: A switching circuit includes a reverse-voltage-blocking (RB) commutation switch, a first inverter leg, and a second inverter leg. The first inverter leg includes a first dual-gate bidirectional (DGBD) and a second DGBD switch connected in series. The second inverter leg includes a third and a fourth DGBD switch connected in series. A pair of the first DGBD switch, the second DGBD switch, the third DGBD switch, and the fourth DGBD switch that are in different inverter legs of the first inverter leg and the second inverter leg are configured to switch between a first DGBD on-state and a second DGBD on-state when in an inverting operating mode. A current with a positive or a negative polarity is conducted when in the first DGBD on-state. When in the second DGBD on-state, a reverse voltage is blocked by and a current with a positive polarity is conducted through the respective DGBD switch.

Abstract: An electric motor having opposed permanent magnet arrays employs overlapping offset coils positioned between the arrays to reduce torque ripple and cogging torque.

Abstract: Stator packages and electric machines, and methods for cooling same, are disclosed herein. In an example embodiment, an electric machine includes a rotor, and a stator package having one or more stator coils, stator core portions, and a heat exchanger. The stator core portions and heat exchanger are arranged successively along a central axis, with the heat exchanger being positioned between the stator core portions. Each of the stator coils is arranged to extend along/within the stator core portions and heat exchanger. The heat exchanger includes walls forming passageways configured so that coolant entering the heat exchanger via an inlet both flows circumferentially from the inlet to an outlet, and additionally flows in an undulating manner both radially inwardly and outwardly substantially in between outer and inner wall surfaces of the heat exchanger, such that the coolant cools the one or more stator coils and the stator core portions.

Abstract: A power converter is provided. In one aspect, the power converter has a first inverter and a second inverter electrically coupled with one another and with a power bus. First switches of the first inverter are arranged symmetrically with second switches of the second inverter so that, when switched in a pulse width modulated switching scheme, the first switches generate a first common mode signal and the second switches generate a second common mode signal that is one hundred eighty degrees out of phase with the first common mode signal. In another aspect, the power converter includes a buck stage having one or more pairs of symmetrically arranged buck switches that can be controlled to reduce or eliminate common mode electromagnetic interference in the buck stage. The power converter can also include one or more pairs of symmetrically arranged inductors.

Abstract: Stator packages and electric machines, and methods for cooling same, are disclosed herein. In an example embodiment, an electric machine includes a rotor, and a stator package having one or more stator coils, stator core portions, and a heat exchanger. The stator core portions and heat exchanger are arranged successively along a central axis, with the heat exchanger being positioned between the stator core portions. Each of the stator coils is arranged to extend along/within the stator core portions and heat exchanger. The heat exchanger includes walls forming passageways configured so that coolant entering the heat exchanger via an inlet both flows circumferentially from the inlet to an outlet, and additionally flows in an undulating manner both radially inwardly and outwardly substantially in between outer and inner wall surfaces of the heat exchanger, such that the coolant cools the one or more stator coils and the stator core portions.

Abstract: An electrical machine includes a rotor, a stator, and a winding mounted within a housing. The rotor includes a rotor core mounted to a shaft and a plurality of blades extending radially away from the rotor core. Each blade of the plurality of blades is curved axially along the rotor core. The stator includes a stator core and a plurality of teeth extending from the stator core toward the rotor core to define a plurality of slots between successive teeth. The winding is wound through at least two slots of the plurality of slots. The stator is mounted radially relative to the rotor. The housing includes a front wall, a back wall, and a radial sidewall mounted between the front wall and the back wall to define an enclosure. A radial inlet aperture wall is formed circumferentially through the radial sidewall to form an opening through the radial sidewall.

Abstract: A switching circuit for a current source inverter includes a first inverter leg, a second inverter leg, and a controller. The first inverter leg includes a first reverse-voltage-blocking (RB) switch, a second RB switch, and a third RB switch that are connected in series between a first bus line and a second bus line. The second inverter leg includes a fourth RB switch, a fifth RB switch, and a sixth RB switch are connected in series between the first bus line and the second bus line. The controller is configured to control a switch between an on-state and an off-state for each RB switch. When in the on-state, a reverse voltage is blocked by a respective RB switch, and a current with a positive polarity is conducted through the respective RB switch. When in the off-state, a voltage and the current are blocked by the respective RB switch.

Abstract: A switching circuit for a current source inverter includes a first inverter leg, a second inverter leg, and a controller. The first inverter leg includes a first reverse-voltage-blocking (RB) switch, a second RB switch, and a third RB switch that are connected in series between a first bus line and a second bus line. The second inverter leg includes a fourth RB switch, a fifth RB switch, and a sixth RB switch are connected in series between the first bus line and the second bus line. The controller is configured to control a switch between an on-state and an off-state for each RB switch. When in the on-state, a reverse voltage is blocked by a respective RB switch, and a current with a positive polarity is conducted through the respective RB switch. When in the off-state, a voltage and the current are blocked by the respective RB switch.

Abstract: A switching circuit includes a reverse-voltage-blocking (RB) commutation switch, a first inverter leg, and a second inverter leg. The first inverter leg includes a first dual-gate bidirectional (DGBD) and a second DGBD switch connected in series. The second inverter leg includes a third and a fourth DGBD switch connected in series. A pair of the first DGBD switch, the second DGBD switch, the third DGBD switch, and the fourth DGBD switch that are in different inverter legs of the first inverter leg and the second inverter leg are configured to switch between a first DGBD on-state and a second DGBD on-state when in an inverting operating mode. A current with a positive or a negative polarity is conducted when in the first DGBD on-state. When in the second DGBD on-state, a reverse voltage is blocked by and a current with a positive polarity is conducted through the respective DGBD switch.

Abstract: A switching circuit includes a diode, a semiconductor switch, and a first bidirectional switch. The semiconductor switch is configured to conduct a first current from a second terminal to a third terminal of the semiconductor switch when a first on-state signal is sent to a first terminal of the semiconductor switch. An anode of the diode is connected to the second terminal of the semiconductor switch, and a cathode of the diode is connected to the third terminal of the semiconductor switch. The first bidirectional switch includes a first terminal, a second terminal connected to the anode of the diode, and a third terminal and is configured to conduct a second current from the second terminal to the third terminal or from the third terminal to the second terminal when a second on-state signal is sent to the first terminal of the first bidirectional switch.

Abstract: The thermal management system for in-slot cooling of electric motors includes separating structures, either in the form of a scaffolding structure or a monolithic winding structure which is placed in between the adjacent winding turns to physically separate the winding turns to define coolant fluid passages for circulation of a coolant fluid in direct contact with the lateral surfaces of the winding turns. The scaffolding and monolithic winding structures are made from an electrically insulating material and are filled with a dielectric fluid that serves both the coolant and the electrical insulator between the winding turns. An end-winding organizer may be positioned at two end regions of each stator tooth to provide a curved surface for the winding turns to be held in tension throughout the 180° winding end turns and is formed with grooves to define the passage for the coolant flow to ensure that the flowing coolant reaches the surface of the innermost winding turns.

Abstract: A switching circuit includes a diode, a semiconductor switch, and a first bidirectional switch. The semiconductor switch is configured to conduct a first current from a second terminal to a third terminal of the semiconductor switch when a first on-state signal is sent to a first terminal of the semiconductor switch. An anode of the diode is connected to the second terminal of the semiconductor switch, and a cathode of the diode is connected to the third terminal of the semiconductor switch. The first bidirectional switch includes a first terminal, a second terminal connected to the anode of the diode, and a third terminal and is configured to conduct a second current from the second terminal to the third terminal or from the third terminal to the second terminal when a second on-state signal is sent to the first terminal of the first bidirectional switch.

Abstract: An electric machine includes a rotor, a stator, and a winding. The rotor includes a rotor core and blades extending from the rotor core. Each blade is curved in an axial direction along the rotor core and is simultaneously configured as a pole that carries a magnetic flux of the electrical machine and as an airfoil that compresses a gas when the rotor is rotated. The gas flows axially between successive blades of the blades. The stator includes a stator core and teeth extending from the stator core toward the blades. Slots are defined between successive teeth. The winding is wound through at least two slots. The stator is mounted radially relative to the rotor so that a gap separates the blades from an exterior face of the teeth that is axially aligned along the stator core to follow an axial edge of a blade of the blades.

Abstract: An electric machine includes a rotor, a first stator, and a second stator. The rotor includes a rotor core and a first and a second plurality of poles mounted to extend radially from the rotor core. The first stator and the second stator each include a stator core, a plurality of teeth mounted to extend from the stator core, and a plurality of permanent magnets mounted as first spokes within the plurality of teeth. The stators are mounted radially relative to a first side of the rotor and separated by a first air gap between the plurality of poles and the plurality of teeth. At least four windings are connected in series and wound about the plurality of teeth. A first flux linkage in a first pair of series connected windings is a mirror image of a second flux linkage in a second pair of series connected windings.

Abstract: An inverter includes a plurality of inverter legs that each includes first, second, and third switches. A first control line connected to the first switch receives a first control signal. A second control line connected to the second switch receives a second control signal. A third control line connected to the third switch receives the first control signal. The first, second, and third switches are connected sequentially in series. A first connector line is connected between the first switch and the second switch and to a first winding of an electric machine. A second connector line is connected between the second switch and the third switch and to a second winding of the electric machine. The second control signal is complementary to the first control signal.

Abstract: An electric machine includes a rotor, a first and second stator, a first and second plurality of permanent magnets, a first and second winding, a third and fourth winding. The first stator and the second stator are mounted axially relative to the rotor. A first permanent magnet and a second permanent magnet of the first plurality of permanent magnets have opposite polarities. A first permanent magnet and a second permanent magnet of the second plurality of permanent magnets have opposite polarities. The first winding, the second winding, the third winding, and the fourth winding are connected in series. An absolute value of an angle offset between the first winding and the third winding and between closest poles of the first plurality of poles and the second plurality of poles is 180 electrical degrees.

Abstract: An electric machine includes a rotor, a stator, and a winding. The rotor includes a rotor core and blades extending from the rotor core. Each blade is curved in an axial direction along the rotor core and is simultaneously configured as a pole that carries a magnetic flux of the electrical machine and as an airfoil that compresses a gas when the rotor is rotated. The gas flows axially between successive blades of the blades. The stator includes a stator core and teeth extending from the stator core toward the blades. Slots are defined between successive teeth. The winding is wound through at least two slots. The stator is mounted radially relative to the rotor so that a gap separates the blades from an exterior face of the teeth that is axially aligned along the stator core to follow an axial edge of a blade of the blades.

Abstract: An electric machine includes a rotor, a first and second stator, a first and second plurality of permanent magnets, a first and second winding, a third and fourth winding. The first stator and the second stator are mounted axially relative to the rotor. A first permanent magnet and a second permanent magnet of the first plurality of permanent magnets have opposite polarities. A first permanent magnet and a second permanent magnet of the second plurality of permanent magnets have opposite polarities. The first winding, the second winding, the third winding, and the fourth winding are connected in series. An absolute value of an angle offset between the first winding and the third winding and between closest poles of the first plurality of poles and the second plurality of poles is 180 electrical degrees.