Abstract: A three-phase alternating current system port is configured to receive or output a three-phase alternating current. M direct current system ports are configured to separately receive or output a direct current, where M is an integer, and M?2. Three power conversion modules are configured to separately receive or output one phase alternating current in the three-phase alternating current. Each power conversion module includes at least one power unit. Each power unit is configured to implement conversion and galvanic isolation between a single-phase alternating current and a direct current. Each power unit includes one alternating current port and M direct current ports. The alternating current ports of the at least one power unit are connected in series and then connected to the three-phase alternating current system port. The M direct current ports of each power unit are separately connected to the M direct current system ports.

Abstract: The present disclosure relates to a quasi-multi-level power converter and a method of operating the same. The power converter is capable of reconciling scalable operation voltage, multiple output voltage levels, controllable voltage rising or decreasing slew rate, and a balance between the high voltage levels and the volume/weight of passive circuit components.

Abstract: The present disclosure provides a power converter, comprising: a positive terminal, a neutral terminal, a negative terminal, a first intermediate node, a second intermediate node, and an AC terminal. Vertical and horizontal switches are configured to switch a DC voltage between the positive and negative terminal to an AC voltage at the AC terminal. The AC voltage comprises three main voltage levels. A transition between any two of the main voltage levels follow a trapezoidal shape with at least one voltage sub-level.

Abstract: Embodiments of this application provide a power conversion circuit. The power conversion circuit includes at least one first power conversion unit connected in series to a first phase line, at least one second power conversion unit connected in series to a second phase line, at least one third power conversion unit connected in series to a third phase line, a plurality of first start circuits connected in series to the first phase line, and a plurality of second start circuits connected in series to the second phase line. Each first start circuit includes a first relay and a first resistor that are connected in parallel, and first relays in all the first start circuits are sequentially closed after the power conversion circuit is powered on, to start the power conversion circuit. Each second start circuit includes a second relay and a second resistor that are connected in parallel.

Abstract: A check valve for low pressure operating conditions includes: a valve cover, a valve body, and an upper diaphragm between the body and the cover. A first pressure cavity is provided on a lower surface of the valve cover and used for accommodating a backward direction medium, a second pressure cavity is machined on an upper surface of the valve body, within which an inflow passage and an outflow passage are provided, an inflow hole is machined from an inner wall of the inflow passage to a bottom face of the second pressure cavity, and a medium enters into the second pressure cavity from the inflow passage via the inflow hole, and applies upward pressure on the upper diaphragm. A backflow channel in communication with the first pressure cavity is machined on a side wall of the outflow passage.

Abstract: The present disclosure refers to an alternating current/direct current (AC/DC) converter for an on board charger (OBC). The AC/DC converter includes a three-phase-input comprising three inputs, a single-stage dual-active bridge (DAB) circuit, and an auxiliary circuit. The auxiliary circuit includes two switching means and an energy storage means, the auxiliary circuit also includes at least two branches, wherein each of the at least two branches include one of the switching means. At least one branch of the at least two branches is connected to a single-phase AC input of the three inputs, and another branch of the at least two branches is connected to an input of the three inputs which is not a single-phase AC input, and the another branch comprises the energy storage means.

Abstract: A solid-state transformer, a power supply device, and a data center, related to the field of power technologies, to resolve problems of low power density and high manufacturing costs of the solid-state transformer. The solid-state transformer includes a housing and M power conversion units. The M power conversion units include a first power conversion circuit, a high-frequency transformer, and a second power conversion circuit, and the first power conversion circuit is coupled to the second power conversion circuit by using the high-frequency transformer. The housing has an insulation base and a conductive enclosure, the conductive enclosure is sleeved on an outer surface of the insulation base. The insulation base has an accommodating cavity, and in the M power conversion units, at least first power conversion circuits are disposed in the accommodating cavity at intervals, where M is an integer greater than 1.

Abstract: This application provides an isolation transformer. The isolation transformer is applicable to a power converter, the power converter further includes a first power conversion module and a second power conversion module, the isolation transformer includes a high-voltage winding, a low-voltage winding, and a solid insulation housing. The high-voltage winding has a solid insulation layer and the solid insulation housing has an opening surface, the opening surface faces the second power conversion module, the solid insulation housing covers the low-voltage winding and the high-voltage winding that has the solid insulation layer, a conducting layer or a semi-conducting layer is disposed on the solid insulation housing, and the conducting layer or the semi-conducting layer of the solid insulation housing is grounded. In this application, a volume of the isolation transformer can be reduced, power density of the power converter can be improved, and low costs and high applicability can be ensured.

Abstract: The original Abstract is canceled in favor of the new Abstract presented on the following page. A power system, related to the field of electronic power. The power system includes a centralized controller and three power modules. Each phase of an alternating current power supply is connected to one power module, and an input end of each power module is connected to one phase of the alternating current power supply. Each power module includes a low voltage controller and at least two power units. Each power unit includes a unit controller. The centralized controller is connected to each low voltage controller by using a bus. The centralized controller sends a control signal to each unit controller by using each low voltage controller, to control the unit controller and/or a power conversion circuit. The power system can implement hot swap of the power module and improve on-site operation reliability.

Abstract: A solid-state transformer (10) that maintains output voltage continuity during maintenance is provided. The solid-state transformer includes an input end (101), a plurality of power units (U1 to UM), and an output end (102). The input end is configured to input first three-phase alternating-current electrical power. The plurality of power units are connected in parallel to the input end and the output end, and each power unit is configured to convert the first three-phase alternating-current electrical power into first direct-current electrical power, and output the first direct-current electrical power from the output end. A power supply system (100) including the foregoing solid-state transformer is further included.

Abstract: Provided is a power supply and distribution system, the power supply and distribution system includes at least one non-isolated AC/DC converter unit, an MV DC bus and multiple isolated DC/DC converter units, and the at least one non-isolated AC/DC converter unit is connected between an MV AC grid and the MV DC bus, and is configured to convert an input MV AC voltage to an output MV DC voltage, where the output MV DC voltage is fed into the MV DC bus, the multiple isolated DC/DC converter units are connected to the MV DC bus in parallel via MV class cables, and are configured to convert a voltage level from the MV DC bus to a charging voltage level. The power supply and distribution system can be used for charging the EVs.

Abstract: This application provides a voltage sampler and a solid-state transformer. The voltage sampler includes a conductive housing, at least one sampling board located inside the housing, and a conducting layer. Each sampling board includes at least two resistors and a voltage input end. The resistors in the sampling board are electrically connected in sequence in the direction from a first end to a second end. The resistor at the first end is electrically connected to the voltage input end. The resistor at the second end is electrically connected to the housing, and the housing is electrically connected to a fixed potential end. The conducting layer is disposed between the at least one sampling board and the housing in the voltage sampler. The conducting layer is electrically connected to a resistor in the sampling board.

Abstract: This application discloses a power electronic transformer wherein each phase includes a plurality of power conversion modules. Each power conversion module includes a rectifier AC/DC circuit, a direct current bus capacitor, and a direct current-direct current DC/DC circuit. In each power conversion module, an output end of the AC/DC circuit is connected to an input end of the DC/DC circuit; the direct current bus capacitor is connected in parallel to the output end of the AC/DC circuit; and input ends of all the AC/DC circuits are connected in series, and output ends of all the DC/DC circuits are connected in parallel. The power electronic transformer includes a relatively small quantity of power conversion modules, thereby reducing occupied space and costs.

Abstract: This application provides a dry-type transformer and a winding method thereof. The dry-type transformer includes a magnetic core, a first coil, a second coil, and a shielding component. The first coil is disposed around the exterior of the magnetic core, and the second coil is disposed around the exterior of the first coil. In a direction from the iron core to the second coil, the shielding component includes a first conducting layer, a second conducting layer, a third conducting layer, and a fourth conducting layer that are sequentially disposed at intervals, the first coil is disposed between the magnetic core and the first conducting layer, and the second coil is disposed between the second conducting layer and the third conducting layer.

Abstract: Embodiments of this application provide a power conversion circuit. The power conversion circuit includes at least one first power conversion unit connected in series to a first phase line, at least one second power conversion unit connected in series to a second phase line, at least one third power conversion unit connected in series to a third phase line, a plurality of first start circuits connected in series to the first phase line, and a plurality of second start circuits connected in series to the second phase line. Each first start circuit includes a first relay and a first resistor that are connected in parallel, and first relays in all the first start circuits are sequentially closed after the power conversion circuit is powered on, to start the power conversion circuit. Each second start circuit includes a second relay and a second resistor that are connected in parallel.

Abstract: A vibration system which does not rely on adhesive assembly includes a first bracket and a vibration assembly. The vibration assembly includes a voice coil portion and a first diaphragm portion. The voice coil portion includes a mounting base and a voice coil body. The voice coil body surrounds an outer surface of the mounting base. Through holes define in one end of the mounting base. The through holes penetrate the base. The first diaphragm portion includes two connecting portions and a diaphragm body between the two connecting portions. A first connecting portion connects the first bracket. A second connecting portion surrounds an end of the mounting base away from the voice coil body, and the second connecting portion inserts into the through hole. The disclosure further provides a loudspeaker and a method for manufacturing the vibration system.

Abstract: A vibration system which does not rely on adhesive assembly includes a first bracket and a vibration assembly. The vibration assembly includes a voice coil portion and a first diaphragm portion. The voice coil portion includes a mounting base and a voice coil body. The voice coil body surrounds an outer surface of the mounting base. Through holes define in one end of the mounting base. The through holes penetrate the base. The first diaphragm portion includes two connecting portions and a diaphragm body between the two connecting portions. A first connecting portion connects the first bracket. A second connecting portion surrounds an end of the mounting base away from the voice coil body, and the second connecting portion inserts into the through hole. The disclosure further provides a loudspeaker and a method for manufacturing the vibration system.

Abstract: A vibration system which does not rely on adhesive assembly includes a first bracket and a vibration assembly. The vibration assembly includes a voice coil portion and a first diaphragm portion. The voice coil portion includes a mounting base and a voice coil body. The voice coil body surrounds an outer surface of the mounting base. Through holes define in one end of the mounting base. The through holes penetrate the base. The first diaphragm portion includes two connecting portions and a diaphragm body between the two connecting portions. A first connecting portion connects the first bracket. A second connecting portion surrounds an end of the mounting base away from the voice coil body, and the second connecting portion inserts into the through hole. The disclosure further provides a loudspeaker and a method for manufacturing the vibration system.