Abstract: A three-phase power supply conversion circuit includes rectifier, energy storage, direct-current load, and control modules. The rectifier module includes a three-phase rectifier bridge including three bridge arms connected in parallel to each other, and a bidirectional switch assembly including three bidirectional switches. One ends of the three bidirectional switches are connected to midpoints of the three bridge arms, respectively. The energy storage module is connected to a direct-current output end of the rectifier module and includes first and second capacitors connected in series to each other. Other ends of the three bidirectional switches are connected between the first and second capacitors. The control module is connected to the bidirectional switch assembly and configured to control the bidirectional switches according to phase voltages of a three-phase alternating-current power supply, to maintain a voltage between two ends of the first or second capacitor at a target voltage.

Abstract: A control method includes, in response to detecting a target-type fault, determining, by a first control device managing a three-phase three-level power supply circuit, a control signal for instructing a first load to stop operating. The first load is connected to one of buses of the three-phase three-level power supply circuit, and the target-type fault is correlated with a second load connected to two of the buses of the three-phase three-level power supply circuit. The method further includes sending the control signal to a second control device via a target communication channel, to instruct the second control device to control the first load to stop operating.

Abstract: A voltage control method includes obtaining two half-bus voltages at a direct current side of a three-level converter, overvoltage protection values of the two half-bus voltages, and a load voltage required by a load. One of the two half-bus voltages is configured to supply voltage to the load. The method further includes determining a voltage control strategy based on a relationship among the two half-bus voltages, the overvoltage protection values, and the load voltage. The voltage control strategy compensates for an output duty ratio of a switch of the three-level converter, such that the one of the two half-bus voltages is greater than or equal to the load voltage and each of the two half-bus voltages is smaller than or equal to a corresponding one of the overvoltage protection values. The method also includes performing voltage control on the two half-bus voltages based on the voltage control strategy.

Abstract: A three-phase power supply conversion circuit includes rectifier, energy storage, direct-current load, and control modules. The rectifier module includes a three-phase rectifier bridge including three bridge arms connected in parallel to each other, and a bidirectional switch assembly including three bidirectional switches. One ends of the three bidirectional switches are connected to midpoints of the three bridge arms, respectively. The energy storage module is connected to a direct-current output end of the rectifier module and includes first and second capacitors connected in series to each other. Other ends of the three bidirectional switches are connected between the first and second capacitors. The control module is connected to the bidirectional switch assembly and configured to control the bidirectional switches according to phase voltages of a three-phase alternating-current power supply, to maintain a voltage between two ends of the first or second capacitor at a target voltage.

Abstract: An electronic circuit includes a rectifier module and an energy storage module. The rectifier module includes a three-phase rectifier bridge including first, second, and third bridge arms connected in parallel to each other, and a bidirectional switch assembly including first, second, and third bidirectional switches. One ends of the first, second, and third bidirectional switches are connected to midpoints of the first, second, and third bridge arms, respectively. The energy storage module is connected to a direct-current output end of the rectifier module and includes two capacitors connected in series to each other. One of the two capacitors is connected in parallel to a direct-current load. Other ends of the first, second, and third bidirectional switches are connected between the two capacitors.