Abstract: A modular multilevel converter (MMC) includes an input conversion module, an output conversion module, a common conversion module, and a common bridge arm. One end of the input conversion module is connected to Vin, the other end of the input conversion module is connected to the common conversion module through the common bridge arm, and the common conversion module is connected to Vin and Vout. One end of the output conversion module is connected to the common conversion module through the common bridge arm, and the other end of the output conversion module is connected to Vout. The input conversion module and the output conversion module share one bus capacitor.

Abstract: This application discloses a non-current equalization UPS apparatus, a current distribution method, and a parallel UPS system. The current distribution method may be applied to any UPS apparatus in a parallel UPS system. A current proportion of a first current output by the any UPS apparatus in a total output current of the parallel UPS system is positively related to a capacity proportion of an available battery capacity of a battery string correspondingly connected to the any UPS apparatus in a total available battery capacity of the parallel UPS system. Therefore, a system backup time of the parallel UPS system can be prolonged, and resource utilization of a battery string with a large available battery capacity can be improved.

Abstract: This application provides an uninterruptible power supply. An input end of the uninterruptible power supply is connected to a power supply by using a first on-off control module. A controller of the uninterruptible power supply is configured to: after receiving a first control signal sent by the first on-off control module, control a current in a circuit connecting the uninterruptible power supply and the first on-off control module to be zero. An output end of the uninterruptible power supply is connected to a load by using a second on-off control module. A controller of the uninterruptible power supply is configured to: after receiving a second control signal sent by the second on-off control module, control the uninterruptible power supply to be turned off.

Abstract: An energy storage system includes a plurality of bidirectional power converters and a plurality of windings. The plurality of windings shares a magnetic core. A controller transfers energy of a target battery to the magnetic core using a target bidirectional power converter and a target winding at a same time. A voltage of the target battery is greater than those of some or all batteries other than the target battery. As the battery is charged and discharged, the voltage of the battery changes, and the controller only needs to find a new target battery to continue discharging until voltages of all the batteries are equalized, for example, voltage differences between all the batteries are all within a preset voltage range.

Abstract: This application provides a power supply system. The power supply system includes first switch module, an UPS, and a plurality of power consumption branches. An input end of the first switch module is connected to a plurality of power supply apparatuses. An output end of the first switch module is connected to an input end of the UPS. The first switch module is switched between the plurality of power supply apparatuses to supply power to the UPS. An output end of the UPS is connected to each power consumption branch. The UPS is configured to receive electric energy and input a first voltage to each power consumption branch. Each power consumption branch includes a first transformer module and at least one power consumption load. The first transformer module is configured to convert the first voltage into a second voltage, and then provide the second voltage to the power consumption load.

Abstract: Embodiments of this application provide an alternating current power supply circuit, a control method for an alternating current power supply circuit. The alternating current power supply circuit includes a rectifier module and an inverter module. The rectifier module includes a first inductor L1, a first branch, a second branch, a third branch, a first capacitor, and a second capacitor, the third branch includes a soft switching cell, the soft switching cell includes a first switching component and a second switching component that are reversely connected in series, and the first branch, the second branch, and the third branch form an I-type three-level topology or a T-type three-level topology. The inverter module includes a second inductor L1, a fourth branch, a fifth branch, a sixth branch, the first capacitor, and the second capacitor, the sixth branch includes the soft switching cell, and the fourth branch, the fifth branch.

Abstract: This application provides an uninterruptible power system and a driving method for an uninterruptible power system, and relates to the field of power conversion technologies, to resolve output interruption of the uninterruptible power system. The uninterruptible power system includes a first power input end, a second power input end, a load end, and a bypass, where the bypass includes a first bidirectional switch, and the first bidirectional switch is connected to the first power input end and the load end, and is configured to control connection or disconnection between the first power input end and the load end; and at least one main circuit, where each main circuit includes a bus and an inverter output unit. An input end of the bus is connected to the second power input end, and an output end of the bus is connected to the inverter output unit.

Abstract: A working method of a modular uninterruptible power supply (UPS) includes: obtaining working parameters of the modular UPS, where the working parameters include an input voltage parameter, a load parameter, and a battery parameter; and adjusting a working mode of a power module in the modular UPS according to at least one of the working parameters of the modular UPS, so that not all power modules are in a same working mode, where the modular UPS includes K working modules, and 2?K.

Abstract: Embodiments of this application provide a power supply circuit, including a first power conversion module, a plurality of battery banks, a first bus, and a second bus. A first wiring terminal of the first power conversion module is connected to the battery bank, a second wiring terminal of the first power conversion module is connected to the first bus and the second bus, and the first power conversion module is configured to: perform direct current to direct current (DC/DC) conversion on a current output by a corresponding battery bank, and output currents to the first bus and the second bus. In this application, a quantity of battery banks are set to be less than a quantity of inverters in a UPS system, so that costs are reduced.

Abstract: A multi-level circuit, a three-phase multi-level circuit, and a control method are provided. The multi-level circuit includes two groups of bus capacitors that are connected in series. The circuit further includes a plurality of switching transistor branches that are connected in parallel to the capacitors, where each switching transistor branch includes a first half bridge and a second half bridge, and a common terminal of the two half bridges is grounded. Furthermore, the circuit includes two coupled inductors, where each input terminal of each coupled inductor is connected to a common terminal of two switching transistors in the first half bridge in the switching transistor branches. In this circuit, a quantity of groups of bus capacitors is decreased and circuit design complexity is reduced. Further, a dropout voltage of the switching transistors is reduced.

Abstract: A working method of a modular uninterruptible power supply (UPS) includes: obtaining working parameters of the modular UPS, where the working parameters include an input voltage parameter, a load parameter, and a battery parameter; and adjusting a working mode of a power module in the modular UPS according to at least one of the working parameters of the modular UPS, so that not all power modules are in a same working mode, where the modular UPS includes K working modules, and 2?K.

Abstract: A multi-level circuit, a three-phase multi-level circuit, and a control method are provided. The multi-level circuit includes two groups of bus capacitors (C1 and C2) that are connected in series; a plurality of switching transistor branches that are connected in parallel to the capacitors, where each switching transistor branch includes a first half bridge (Q1 and Q2) and a second half bridge (Q3 and Q4), and a common terminal of the two half bridges is grounded (N); and two negative coupled inductors (L1 and L2), where each input terminal of each negative coupled inductor is connected to a common terminal (A1 and A2) of two switching transistors in the first half bridge in only one of the switching transistor branches. In this circuit, a quantity of groups of bus capacitors is decreased and circuit design complexity is reduced. Further, a dropout voltage of the switching transistors is reduced.

Abstract: This application provides a battery equalization circuit to resolve a problem of insufficient charging or discharging of some batteries due to differences between a plurality of batteries in a battery group. Equalization sub-circuits of the battery equalization circuit each include a battery cell, a first bidirectional switch, and a second bidirectional switch. Battery cells of the plurality of equalization sub-circuits are connected in series. When a strobe terminal of the first bidirectional switch receives a turning-on signal, the first bidirectional switch is turned on and couples the positive electrode of the battery cell to a first terminal of an energy storage device. When a strobe terminal of the second bidirectional switch receives a turning-on signal, the second bidirectional switch is turned on and couples the negative electrode of the battery cell to the second terminal of the energy storage device.

Abstract: A bridge circuit for an inverter or a rectifier, includes a first switch, a second switch, a third switch, and a fourth switch that are mutually connected in series and that are electrically connected between a positive direct current voltage source and a negative direct current voltage source. The first switch and the second switch include at least one combined field effect transistor; and the third switch and the fourth switch include at least one combined field effect transistor. The combined field effect transistor is a high withstand voltage field effect transistor and a low withstand voltage field effect transistor whose sources or drains are electrically connected to each other. Parasitic diodes in the combined field effect transistor are reversely connected in series. Therefore, a path of a freewheeling current in the parasitic diodes is blocked, and a switching loss and a spike voltage are reduced.

Abstract: A multi-level circuit, a three-phase multi-level circuit, and a control method are provided. The multi-level circuit includes two groups of bus capacitors (C1 and C2) that are connected in series; a plurality of switching transistor branches that are connected in parallel to the capacitors, where each switching transistor branch includes a first half bridge (Q1 and Q2) and a second half bridge (Q3 and Q4), and a common terminal of the two half bridges is grounded (N); and two negative coupled inductors (L1 and L2), where each input terminal of each negative coupled inductor is connected to a common terminal (A1 and A2) of two switching transistors in the first half bridge in only one of the switching transistor branches. In this circuit, a quantity of groups of bus capacitors is decreased and circuit design complexity is reduced. Further, a dropout voltage of the switching transistors is reduced.

Abstract: A working method of a modular uninterruptible power supply (UPS) includes: obtaining working parameters of the modular UPS, where the working parameters include an input voltage parameter, a load parameter, and a battery parameter; and adjusting a working mode of a power module in the modular UPS according to at least one of the working parameters of the modular UPS, so that not all power modules are in a same working mode, where the modular UPS includes K working modules, and 2?K.

Abstract: This disclosure relates to an equivalent transistor and a three-level inverter, and pertains to the field of power electronics technologies. The equivalent transistor includes a first transistor, a second transistor, and a diode. A source electrode of the first transistor is electrically connected to a source electrode of the second transistor; a gate electrode of the first transistor is electrically connected to a gate electrode of the second transistor; and one end of the diode is electrically connected to a drain electrode of the first transistor, and the other end of the diode is electrically connected to a drain electrode of the second transistor. According to this disclosure, a reverse recovery time can be reduced, and a switching speed of the equivalent transistor can increase.

Abstract: This disclosure relates to an equivalent transistor and a three-level inverter, and pertains to the field of power electronics technologies. The equivalent transistor includes a first transistor, a second transistor, and a diode. A source electrode of the first transistor is electrically connected to a source electrode of the second transistor; a gate electrode of the first transistor is electrically connected to a gate electrode of the second transistor; and one end of the diode is electrically connected to a drain electrode of the first transistor, and the other end of the diode is electrically connected to a drain electrode of the second transistor. According to this disclosure, a reverse recovery time can be reduced, and a switching speed of the equivalent transistor can increase.

Abstract: An uninterruptible power system is provided. When a first power supply of the system is faulty, in a process in which a switch unit switches power supply from the first power supply to a second power supply, the second power supply discharges to a direct current bus using a bidirectional power converter, electric energy stored in the direct current bus is also discharged in a short time in a process of the switch, and the direct current bus outputs both a discharging current of the second power supply and a discharging current of the direct current bus to a system output end, which ensures that the direct current bus outputs a stable voltage in a gap period of an action of the switch unit.

Abstract: An uninterruptible power system is provided. When a first power supply of the system is faulty, in a process in which a switch unit switches power supply from the first power supply to a second power supply, the second power supply discharges to a direct current bus using a bidirectional power converter, electric energy stored in the direct current bus is also discharged in a short time in a process of the switch, and the direct current bus outputs both a discharging current of the second power supply and a discharging current of the direct current bus to a system output end, which ensures that the direct current bus outputs a stable voltage in a gap period of an action of the switch unit.