Abstract: A multiple-phase electric machine provided with multiple inverter power circuits is described herein. The present multiple-phase electric machine aim at performing configuration changes while reducing the loss of torque when machines are switched between configurations. This is done by forming groups of phases defining machine portions that are powered by a separate inverter power circuit and by switching the machine portions separately with controlled switching devices.

Abstract: The present disclosure relates to a circuit for providing a current from a source to a load. A commutation cell includes a main switch that controls a voltage applied by the source to the load. An opposite switch maintains the current in the load when the load is disconnected from the source by the main switch. The opposite switch returns the load current to the main switch when the main switch connects again the load to the source. The disclosed circuit configuration reduces recovery current, losses and electromagnetic losses. A synchronizing controller controls opening and closing sequences of the main switch and of the opposite switch. The disclosed circuit can provide a DC-DC voltage converter. Combining two such circuits can provide a DC-AC voltage converter.

Abstract: The present disclosure relates to a commutation cell and to a compensation circuit for limiting overvoltage across the power electronic switch of the commutation cell and for limiting a recovery current in a freewheel diode of the commutation cell. The power electronic switch has a parasitic emitter inductance. A variable gain compensation circuit generates a feedback from a voltage generated across the parasitic inductance of the emitter of the power switch at turn-on or turn-off of the power electronic switch. The compensation circuit provides the feedback to a control of the power electronic switch to reduce the voltage generated on the parasitic emitter inductance. A power converter including the commutation cell with the compensation circuit is also disclosed.

Abstract: The external rotor for an electric machine includes a cylindrically shaped receptacle having a peripheral wall and a magnet-receiving assembly including segments assembled to the inner surface of the peripheral wall so as to define a cylindrically shaped stack. The segments are shaped so as to yield magnet-receiving portions in the ring-shaped stack, and permanent magnets are secured to the magnet-receiving portion of the magnet receiving assembly.

Abstract: The present disclosure relates to a power converter configured for limiting switching overvoltage. The power converter comprises a bottom commutation cell that includes a bottom power electronic switch and a bottom compensation circuit connected to a bottom parasitic inductance. The bottom compensation circuit applies a sample of the voltage induced across the bottom parasitic inductance at turn-off of the bottom power electronic switch to the reference node of the bottom gate driver. The power converter also comprises a top commutation cell that includes top power electronic switch and a top compensation circuit connected to the bottom parasitic inductance. The top compensation circuit applies a sample of the voltage induced across the bottom parasitic emitter upon turn-off of the top power electronic switch to the reference node of the top gate driver.

Abstract: An embodiment of a liquid cooled electric machine is provided with an enclosed stator and includes a cooling assembly so configured as to allow cooling liquid to flow in the coil receiving slots of the enclosed stator to thereby cool the coils positioned therein.

Abstract: A physical topology for receiving top and bottom power electronic switches comprises a top collector trace connected to a positive voltage power supply tab and having a connection area for a collector of a top power electronic switch, a bottom emitter trace connected to a negative voltage power supply tab and having a connection area for an emitter of the bottom power electronic switch, and a middle trace connected to a load tab and having a connection area for an emitter of the top power electronic switch and a connection area for a collector of the bottom power electronic switch. Sampling points are provided on the traces for voltages on the emitters of the top and bottom power electronic switches, on the trace for voltage of the collector of the bottom power electronic switch, and on the negative voltage power supply tab. The topology defines parasitic inductances.

Abstract: A cooling arrangement cast into a generally cylindrical stator having longitudinal channels provided on an internal surface thereof is described herein. The cast cooling arrangement comprising a cast heat-storing element and conduits defining a cooling path having an inlet and an outlet.

Abstract: A turn-off overvoltage limiting for IGBT is described herein. The injection of a sample of the overvoltage across the IGBT in the gate drive to slow down the slope of the gate voltage decrease only during the overvoltage above a predetermined value is described herein. Techniques to increase the parasitic inductance to allow the control to limit an overvoltage at turn off of the second IGBT are also described herein.

Abstract: The present disclosure relates to a circuit for providing a current from a source to a load. A commutation cell includes a main switch that controls a voltage applied by the source to the load. An opposite switch maintains the current in the load when the load is disconnected from the source by the main switch. The opposite switch returns the load current to the main switch when the main switch connects again the load to the source. The disclosed circuit configuration reduces recovery current, losses and electromagnetic losses. A synchronizing controller controls opening and closing sequences of the main switch and of the opposite switch. The disclosed circuit can provide a DC-DC voltage converter. Combining two such circuits can provide a DC-AC voltage converter.

Abstract: The present disclosure relates to a power converter configured for limiting switching overvoltage. The power converter comprises a bottom commutation cell that includes a bottom power electronic switch and a bottom compensation circuit connected to a bottom parasitic inductance. The bottom compensation circuit applies a sample of the voltage induced across the bottom parasitic inductance at turn-off of the bottom power electronic switch to the reference node of the bottom gate driver. The power converter also comprises a top commutation cell that includes top power electronic switch and a top compensation circuit connected to the bottom parasitic inductance. The top compensation circuit applies a sample of the voltage induced across the bottom parasitic emitter upon turn-off of the top power electronic switch to the reference node of the top gate driver.

Abstract: A cooling arrangement cast into a generally cylindrical stator having longitudinal channels provided on an internal surface thereof is described herein. The cast cooling arrangement comprising a cast heat-storing element and conduits defining a cooling path having an inlet and an outlet.

Abstract: A reluctance assisted external rotor permanent magnet machine provided with fewer magnets without scarifying performance is described herein. Torque ripple and cogging torque reductions are discussed.

Abstract: A machine that forms the heads of coils made of rectangular wire so that it fits within the slots of the stator of an electric machine is described herein. The machine receives a coil having unformed first and second heads separated by first and second legs and apply controlled deformation thereto to yield properly shaped heads. The machine comprises first and second leg support mechanisms for gripping the first and second legs and head-forming elements for contacting portions of the heads of the wire coil while the first and second legs are gripped by the leg support. The head-forming elements are mounted to the first and second leg support mechanisms.

Abstract: A physical topology for receiving top and bottom power electronic switches comprises a top collector trace connected to a positive voltage power supply tab and having a connection area for a collector of a top power electronic switch, a bottom emitter trace connected to a negative voltage power supply tab and having a connection area for an emitter of the bottom power electronic switch, and a middle trace connected to a load tab and having a connection area for an emitter of the top power electronic switch and a connection area for a collector of the bottom power electronic switch. Sampling points are provided on the traces for voltages on the emitters of the top and bottom power electronic switches, on the trace for voltage of the collector of the bottom power electronic switch, and on the negative voltage power supply tab. The topology defines parasitic inductances. Sample voltages can be supplied to gate driver references.

Abstract: A commutation cell is configured for limiting switching overvoltage. The commutation cell includes a power electronic switch having a parasitic emitter inductance through which a voltage is generated upon turning off of the power electronic switch. The commutation cell also includes a dynamically controlled compensation circuit connected to the parasitic emitter inductance. The compensation circuit applies a controllable portion of the voltage generated through the parasitic emitter inductance at turn-off of the power electronic switch to control the voltage generated through the parasitic emitter inductance. A power converter includes a pair of commutation cells and a compensation circuit of the commutation cell.

Abstract: The present topology for controlled power switch module is concerned with a module where the parasitic inductance of the emitter of the top power switch is optimized to allow the injection of a sample of the overvoltage across this parasitic inductance in the gate drive circuit of the top power switch as a feedback to slow down the slope of the falling gate voltage during an overvoltage that is above a predetermined value.

Abstract: The present disclosure relates to a power converter configured for limiting switching overvoltage. The power converter comprises a pair of commutation cells. Each commutation cell includes a power electronic switch and a gate driver connected to a gate of the power electronic switch. A reference of the gate driver of a first commutation cell is connected to a ground of the power converter while a reference of the gate driver of a second commutation cell is connected to a collector of the power electronic switch of the first commutation cell. The gate driver of the second commutation cell has no negative voltage power input, either through using a single voltage power supply or by connecting a negative voltage connection of the dual voltage power supply to ground.

Abstract: The present disclosure relates to a compensation circuit for independently controlling turn-on and turn-off of a power electronic switch through a gate driver. The compensation circuit includes a circuit path sampling a first portion of a voltage induced across an inductance of the power electronic switch at turn-on. Another circuit path samples a second portion of the voltage induced across the inductance of the power electronic switch at turn-off. The compensation circuit further includes a gate driver reference connection configured to respectively supply the sampled portions of the voltage during turn-on and turn-off of the power electronic switch. A compensation circuit controlling a first power electronic switch in parallel with a second power electronic switch, a commutation cell and a power converter having a pair of parallel legs, in which each power electronic switch is provided with the compensation circuit, are also disclosed.

Abstract: A cooling arrangement for electric machines where cooling plates are maintained against the inner surface of the stator and are interconnected by a cooling tube that carries the stator generated heat outside of the machine.