Abstract: Provided are a beveled light-emitting lamp bead, a beveled light-emitting lamp bead holder, a manufacturing method therefor, and a display device. The beveled light-emitting lamp bead holder includes a holder body and a metal holder embedded in the holder body, where the holder body is divided by the metal holder into a cup shield located on a top side and a support structure located on a bottom side, a cup bottom in the cup shield is provided with a chip mounting surface parallel to a cup rim top surface, a bottom portion of the support structure is provided with a soldering plane, the soldering plane is electrically connected to the chip mounting surface through the metal holder, and an inclination angle is formed between the chip mounting surface and the soldering plane.

Abstract: A static transfer switch is provided for supplying power to a load alternately from two different power sources. Preferably, switching between the two power sources occurs within one electrical cycle. In order to control inrush currents and reduce disruption during power transfers between the two power sources, switches are provided to configure which input phases are connected to the output phases.

Abstract: Unique systems, methods, techniques and apparatuses of photovoltaic (PV) string power systems are disclosed. One exemplary embodiment is a PV power system comprising a plurality of PV strings and a floating DC-DC optimizer. The floating DC-DC optimizer comprises a first DC bus rail, a second DC bus rail, a plurality of input legs, each leg being coupled across the first DC bus rail and second DC bus rail, including two input leg semiconductor switches coupled at an input terminal, each input terminal being structured to receive an input current from an end of one PV string of the plurality of PV strings, and an output leg including two output leg semiconductor devices coupled at an output terminal.

Abstract: Systems, methods, techniques and apparatuses of power switch protection are disclosed. One exemplary embodiment is a protection system for a power switch comprising a resistor and a detection circuit. The resistor is coupled in series with a decoupling capacitor. The detection circuit is structured to receive a voltage of the resistor, determine a short circuit is occurring based on the received electrical characteristic, and transmit a fault trigger signal in response to determining the short circuit is occurring.

Abstract: There are disclosed winding configurations for electric machines that employ printed circuit board (PCB) type end winding connections to enable an automatic and faster assembly of the electric machines. The winding configurations provide a compact PCB-type end winding arrangement with an optimal fewer number of turns/bars in the slots of the board to complete the loop of winding connections. The winding configurations have application in three phase or multiple phase inner rotor or outer rotor electric machine topologies.

Abstract: An industrial electrical machine includes a stator; a rotor in magnetic communication with the stator; a plurality of windings disposed in the rotor and/or the stator; and an embedded solid state controller. The solid state controller is operative to control the operation of the industrial electrical machine. The solid state controller includes a power semiconductor switching device coupled to the plurality of windings, and includes a communication interface. The power semiconductor switching device is operative to provide switching during operation of the industrial electrical machine, and is operative to turn the electrical machine on and to turn the electrical machine off in response to a control input received by the communication interface.

Abstract: A surge arrester system includes a surge arrester, and an active cooling system having a cooling interface in contact with the surge arrester and operative to transfer heat from the surge arrester. The active cooling system includes a forced convection apparatus operative to provide forced convection cooling. A circuit breaker system includes a power semiconductor switch and an active cooling system constructed to cool the power semiconductor switch. The active cooling system includes a forced convection apparatus configured to provide forced convection cooling. The power semiconductor switch is in contact with the active cooling system. A surge arrester is disposed adjacent to and in contact with the active cooling system. The active cooling system includes a cooling interface constructed for contact with the surge arrester and operative to provide cooling to the surge arrester. The power semiconductor switch and the surge arrester dissipate power alternatively.

Abstract: A resonant turn-off circuit is provided to disconnect an inadequate power source and transfer a load to an alternate power source. In the circuit, a main switch is turned off before the AC cycle of the power source crosses zero. As a result, the main switch may be turned off quickly to transfer electric power supplied to a load to a second power source. The circuit may include resonant switches, a capacitor, a pre-charging power supply and an inductor. When it is desired to turn off the main switch, a resonant switch is turned off to cause a voltage reversal across the switch.

Abstract: A unique system may include a power absorber; an electrical machine coupled to the power absorber and operative to supply mechanical power to the power absorber; a drive coupled to the electrical machine and operative to supply electrical power to drive the electrical machine; and a controller communicatively coupled to the drive. The controller may be configured to execute program instructions to selectively vary a control voltage while maintaining a given torque output of the electrical machine, and to determine, based on varying the control voltage, a minimum current required for the electrical machine to maintain the given torque output.

Abstract: A resonant turn-off circuit is provided to disconnect an inadequate power source and transfer a load to an alternate power source. In the circuit, a main switch is turned off before the AC cycle of the power source crosses zero. As a result, the main switch may be turned off quickly to transfer electric power supplied to a load to a second power source. The circuit may include resonant switches, a capacitor, a pre-charging power supply and an inductor. When it is desired to turn off the main switch, a resonant switch is turned off to cause a voltage reversal across the switch.

Abstract: Unique systems, methods, techniques and apparatuses of photovoltaic (PV) string power systems are disclosed. One exemplary embodiment is a PV power system comprising a plurality of PV strings and a floating DC-DC optimizer. The floating DC-DC optimizer comprises a first DC bus rail, a second DC bus rail, a plurality of input legs, each leg being coupled across the first DC bus rail and second DC bus rail, including two input leg semiconductor switches coupled at an input terminal, each input terminal being structured to receive an input current from an end of one PV string of the plurality of PV strings, and an output leg including two output leg semiconductor devices coupled at an output terminal.

Abstract: A sliding contact assembly for a DC electrical outlet receives plug contacts of an electrical plug. The assembly includes sliding contact structure having a base and a plurality of electrical sliding contacts fixed to the base. A housing includes a first end wall having an internal top surface and second end wall opposing the first end wall. The second end wall has an internal bottom surface. The housing has a side wall structure defining an internal chamber between the top surface and the bottom surface. The sliding contact structure is disposed in the housing to be movable linearly within the chamber. A spring is disposed between the top surface of the housing and a surface of the base so that when the plug contacts are completely disconnected from the associated sliding contacts, the spring rapidly forces the sliding contacts away from the plug contacts, reducing arcing energy there-between.

Abstract: The subject matter described herein includes a fan assembly for cooling an electric machine and an electric machine incorporating such a fan assembly. One exemplary fan assembly according to the subject matter described herein includes a first fan annulus for surrounding a portion of an electric machine. The fan assembly further includes a fan drive circuit for driving the first fan annulus separately from a drive mechanism of the electric machine. The first fan annulus is configured to be, when rotating to cool the electric machine, mechanically disconnected from a housing and a rotor of the electric machine and separated from the housing by radial gap.

Abstract: A synchronous machine system comprising a synchronous motor including a stator, stator winding, rotor, and field winding; an AC power supply circuit structured to transmit current to or from the stator winding of the synchronous motor at a controlled frequency and transmit current to or from a power source at a controlled frequency; a DC exciter unit structured to receive power from a power source, convert the received power to DC power at a desired voltage, and supply the converted power across a DC bus to the field winding of the synchronous motor; and an energy storage circuit coupled to the DC bus of the DC exciter unit having at least one ultracapacitor, and structured to receive power from a power source, to charge the ultracapacitor, and to provide power to the field winding of the synchronous motor following a power failure.

Abstract: An electrical machine includes a stator core and a plurality of windings subdivided into a plurality of multiphase motor cells, each multiphase motor cell having M windings associated therewith, and having a phase shift relative to other multiphase motor cells. The electrical machine may include N inverter cells coupled in series; wherein each inverter cell is a multiphase inverter; and wherein the voltage magnitude supplied to a corresponding multiphase motor cell is VDC/N. The electrical machine may include a sensor system in communication with the plurality of inverter cells and operative to commutate each inverter cell in a sequence.

Abstract: A surge arrester system includes a surge arrester, and an active cooling system having a cooling interface in contact with the surge arrester and operative to transfer heat from the surge arrester. The active cooling system includes a forced convection apparatus operative to provide forced convection cooling. A circuit breaker system includes a power semiconductor switch and an active cooling system constructed to cool the power semiconductor switch. The active cooling system includes a forced convection apparatus configured to provide forced convection cooling. The power semiconductor switch is in contact with the active cooling system. A surge arrester is disposed adjacent to and in contact with the active cooling system. The active cooling system includes a cooling interface constructed for contact with the surge arrester and operative to provide cooling to the surge arrester. The power semiconductor switch and the surge arrester dissipate power alternatively.

Abstract: There are disclosed winding configurations for electric machines that employ printed circuit board (PCB) type end winding connections to enable an automatic and faster assembly of the electric machines. The winding configurations provide a compact PCB-type end winding arrangement with an optimal fewer number of turns/bars in the slots of the board to complete the loop of winding connections.

Abstract: The subject matter described herein includes a multiphase fractional slot concentrated winding machine. One such machine includes a machine module including a rotor and a stator. The stator includes a plurality of radially extending teeth. Each tooth is individually wound with a coil. The machine further includes a multiphase series converter circuit physically connected to an end of the machine module to energize the coils for multiphase operation.

Abstract: An industrial electrical machine includes a stator; a rotor in magnetic communication with the stator; a plurality of windings disposed in the rotor and/or the stator; and an embedded solid state controller. The solid state controller is operative to control the operation of the industrial electrical machine. The solid state controller includes a power semiconductor switching device coupled to the plurality of windings, and includes a communication interface. The power semiconductor switching device is operative to provide switching during operation of the industrial electrical machine, and is operative to turn the electrical machine on and to turn the electrical machine off in response to a control input received by the communication interface.

Abstract: A sliding contact assembly for a DC electrical outlet receives plug contacts of an electrical plug. The assembly includes sliding contact structure having a base and a plurality of electrical sliding contacts fixed to the base. A housing includes a first end wall having an internal top surface and second end wall opposing the first end wall. The second end wall has an internal bottom surface. The housing has a side wall structure defining an internal chamber between the top surface and the bottom surface. The sliding contact structure is disposed in the housing to be movable linearly within the chamber. A spring is disposed between the top surface of the housing and a surface of the base so that when the plug contacts are completely disconnected from the associated sliding contacts, the spring rapidly forces the sliding contacts away from the plug contacts, reducing arcing energy there-between.