Controllable turn-off hybrid grid commutator converter control method, device and system

Abstract

The application discloses a controllable turn-off hybrid grid commutation converter control method, device and system, and belongs to the technical field of high-voltage direct current transmission. The control method comprises the following steps: when the AC side of the converter is electrified and the main circuit is not unlocked, in the case that at least one phase of the upper bridge transfer circuit or the lower bridge transfer circuit bears a forward voltage, the upper bridge transfer circuit or the lower bridge transfer circuit is controlled to be turned on; when the controllable turn-off hybrid grid commutation converter is unlocked and normally operated, in the case that the current of the main circuit is lower than a preset threshold, the auxiliary circuit parallel to the main circuit is controlled to be turned on or to present a negative voltage so as to turn off the main circuit. In the application, the turn-off circuit is electrified and self-checking is realized by controlling the transfer circuit to be turned on without increasing the hardware circuit cost of the controllable turn-off hybrid grid commutation converter; in the normal operation, the full-control valve of the main circuit is controlled to be turned off with zero current, and the service life of the arrester parallel to the full-control valve is prevented from being affected by continuous action.

Description

Technical Field

[0001] This application relates to the field of high voltage direct current transmission technology, specifically to a controllable shutdown hybrid grid phase converter control method, device, and system. Background Technology

[0002] With the increasing number of high-voltage and ultra-high-voltage direct current (HVDC) transmission systems connected to the grid, multi-feed HVDC transmission systems have been formed in multiple regional power grids. When multiple HVDC lines fail to commutate simultaneously, it may pose a threat to the safe operation of the AC power grid in that region. Furthermore, as the proportion of renewable energy generation increases, the AC voltage support capacity decreases, placing higher demands on the stable operation of HVDC transmission systems and their ability to suppress commutation failures.

[0003] In relevant DC transmission technologies, grid-commutated converters with a twelve-pulse circuit structure are mainly used. To address the commutation failure issue in grid-commutated converters, a hybrid line commutation converter (HLCC) with controllable shutdown can suppress commutation failure by adding auxiliary circuits. However, if the three-phase AC voltages are perfectly symmetrical and the three-phase circuit parameters are identical, during AC side charging of the converter, the controllable shutdown hybrid line commutation converter with centralized shutdown circuit configuration will have no voltage across the shutdown circuit, preventing the transmission of the shutdown state. Furthermore, if the main circuit continuously interrupts the current, it will cause the surge arresters in the main circuit to continuously operate during steady-state operation, affecting the surge arrester lifespan and reducing the converter's reliability. Summary of the Invention

[0004] This invention provides a controllable shutdown hybrid grid phase-change converter control method, device and system, which aims to solve the problem that the shutdown circuit is not energized when the AC side of the converter is charging, the main circuit shutdown current causes the surge arrester to operate continuously, and the converter has low reliability.

[0005] In a first aspect, embodiments of this application provide a controllable shutdown hybrid grid phase-change converter control method, comprising: When the AC side of the controllable shut-off hybrid grid phase converter is energized and the main circuit is not unlocked, select at least one phase of the upper bridge transfer circuit and at least one phase of the lower bridge transfer circuit. When the upper bridge transfer circuit of at least one phase is subjected to a positive voltage, control the upper bridge transfer circuit to be turned on or partially turned on. When the lower bridge transfer circuit of at least one phase is subjected to a positive voltage, control the lower bridge transfer circuit to be turned on or partially turned on; and / or; When the controllable shutdown hybrid grid phase converter is unlocked and operating normally, if the current in the main circuit is lower than a preset threshold, the auxiliary circuit connected in parallel with the main circuit is controlled to conduct or present a negative voltage, thereby controlling the main circuit to shut down or using the negative voltage to shut down the main circuit.

[0006] In one embodiment of this application, the control of the upper bridge transfer circuit to be turned on or partially turned on, or the control of the lower bridge transfer circuit to be turned on or partially turned on, is an immediate control or a delayed control; the delayed control includes the delay when the controllable shutdown hybrid grid phase converter is energized but the main circuit is not unlocked, and / or the delay after the upper bridge transfer circuit or the lower bridge transfer circuit is subjected to a positive voltage.

[0007] In one embodiment of this application, the control method further includes: After controlling the upper bridge transfer circuit to be turned on or partially turned on, the operating status of the upper bridge shutdown circuit is detected. If the upper bridge shutdown circuit is in normal condition, a signal indicating that the upper bridge shutdown circuit is energized and set is generated and sent to the valve control device. After controlling the lower bridge transfer circuit to be turned on or partially turned on, the operating status of the lower bridge shutdown circuit is detected. If the lower bridge shutdown circuit is in normal condition, a signal indicating that the lower bridge shutdown circuit is energized and set is generated and sent to the valve control device.

[0008] In one embodiment of this application, the control method further includes: When the valve control device receives a signal indicating that the upper bridge shutdown circuit or the lower bridge shutdown circuit is energized, it maintains the first time threshold, or maintains the signal until the valve group is unlocked, or maintains the signal until the valve group is de-energized.

[0009] In one embodiment of this application, the control method further includes: After the valve control device receives the normal energization signal of the upper bridge shutdown circuit, when at least one phase of the upper bridge transfer circuit is subjected to a positive voltage, it stops triggering the upper bridge transfer circuit to conduct or partially conduct. After the valve control device receives the normal energization signal of the lower bridge shutdown circuit, it stops triggering the lower bridge transfer circuit to conduct or partially conduct when at least one phase of the lower bridge transfer circuit is subjected to a positive voltage.

[0010] In one embodiment of this application, the method for determining that the main circuit current is lower than the preset threshold includes at least one of the following: The current in the main circuit is determined to be less than a first current threshold, wherein the value of the first current threshold is in the range of -100A to 100A. Based on the triggering time and commutation time of the controllable shutdown hybrid power grid commutator, the prediction is made after the commutation process is completed.

[0011] In one embodiment of this application, when the current of the main circuit is lower than a preset threshold, the auxiliary circuit connected in parallel with the main circuit is turned on, and after a second time threshold, the main circuit is turned off; the second time threshold ranges from 0 to 1 ms.

[0012] In one embodiment of this application, the control method further includes: Obtain the operating parameter information of the controllable shutdown hybrid grid phase converter; Inverter state control information is generated based on the aforementioned operating parameter information; Based on the inverter state control information, the main circuit is controlled to operate in inverter state.

[0013] In one embodiment of this application, the control method further includes: Upon obtaining the commutation fault information of the controllable shutdown hybrid power grid commutator, a circuit turn-on command and a first circuit turn-off command are generated based on the commutation fault information. Based on the circuit turn-on command, the transfer circuit and / or turn-off circuit in the auxiliary circuit corresponding to the commutation bridge arm are turned on; based on the first circuit turn-off command, the first full control valve included in the commutation bridge arm is turned off or the second full control valve is at negative pressure; wherein, the commutation bridge arm is an upper bridge arm circuit or a lower bridge arm circuit. When the first half-control valve of the commutation bridge arm in the main circuit is restored to shutdown, a second circuit shutdown command is generated to control the shutdown circuit in the auxiliary circuit corresponding to the commutation bridge arm to shut down.

[0014] In one embodiment of this application, when the commutation bridge arm is the upper bridge arm circuit, the transfer circuit in the auxiliary circuit corresponding to the commutation bridge arm is the upper bridge transfer circuit that is in phase with the upper bridge arm circuit, and the shutdown circuit in the auxiliary circuit corresponding to the commutation bridge arm is the upper bridge shutdown circuit. When the commutation bridge arm is the lower bridge arm circuit, the transfer circuit in the auxiliary circuit corresponding to the commutation bridge arm is the lower bridge transfer circuit that is in phase with the lower bridge arm circuit, and the shutdown circuit in the auxiliary circuit corresponding to the commutation bridge arm is the lower bridge shutdown circuit.

[0015] In one embodiment of this application, the control method further includes: It is determined whether the first semi-controlled valve included in the commutation bridge arm of the main circuit has resumed shutdown. The shutdown of the first semi-controlled valve is determined based on the reverse recovery time of the first semi-controlled valve, which is greater than or equal to the reverse recovery time of the thyristor included in the first semi-controlled valve.

[0016] In one embodiment of this application, the control method further includes: If fault information of the auxiliary circuit is obtained, a switch-off command is generated based on the fault information of the auxiliary circuit. Based on the switch separation command, the corresponding isolating switch and / or knife switch of the auxiliary circuit are controlled to separate.

[0017] In one embodiment of this application, the control method further includes: When a fourth semi-control valve is connected in parallel across the first fully control valve, and overpressure or fault information of the first fully control valve is obtained, a first valve opening command is generated, and the fourth semi-control valve is controlled to open based on the first valve opening command; or; When a second uncontrolled valve is connected in series with the first fully controlled valve, and a fourth semi-controlled valve is connected in parallel at both ends of the series connection between the first fully controlled valve and the second uncontrolled valve, and when overpressure information or fault information of the first fully controlled valve is obtained, a second valve opening command is generated, and the fourth semi-controlled valve is controlled to open based on the second valve opening command.

[0018] Secondly, embodiments of this application provide a controllable shutdown hybrid grid phase-change converter control device, comprising: The first control module is configured to, when the AC side of the controllable shut-off hybrid grid phase-change converter is energized and the main circuit is not unlocked, select at least one phase of the upper bridge transfer circuit and at least one phase of the lower bridge transfer circuit; when the upper bridge transfer circuit of at least one phase is subjected to a positive voltage, control the upper bridge transfer circuit to be turned on or partially turned on; and when the lower bridge transfer circuit of at least one phase is subjected to a positive voltage, control the lower bridge transfer circuit to be turned on or partially turned on; and / or; The second control module is used to control the auxiliary circuit connected in parallel with the main circuit to conduct or present a negative voltage when the controllable shutdown hybrid grid phase converter is unlocked and operating normally, and when the current of the main circuit is lower than a preset threshold, thereby controlling the main circuit to shut down or using the negative voltage to shut down the main circuit.

[0019] Thirdly, embodiments of this application provide a controllable shutdown hybrid grid phase-commutator system, including the aforementioned controllable shutdown hybrid grid phase-commutator control device.

[0020] The beneficial effects of this application are as follows: Without increasing the hardware circuit cost of the controllable shutdown hybrid grid commutator, this application achieves the energization of the shutdown circuit and enables self-testing by controlling the conduction or partial conduction of the transfer circuit when the circuit is energized and the main circuit is not unlocked; during normal operation, the control valve of the main circuit is shut off with zero current, preventing the surge arrester connected in parallel with the control valve from continuously operating and affecting its lifespan, thus improving the reliability of the converter. At the same time, the current only flows in the main circuit, improving the efficiency of the converter; in the event of AC system failure, the auxiliary circuit generates the commutation voltage to suppress commutation failure and improve the reliability of high voltage direct current transmission. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is one of the schematic diagrams of a controllable shutdown hybrid grid phase-commutation converter according to an embodiment of this application; Figure 2 This is a second schematic diagram of a controllable shutdown hybrid grid phase-commutation converter according to an embodiment of this application; Figure 3 This is the third schematic diagram of the controllable shutdown hybrid grid phase-commutation converter in the embodiments of this application; Figure 4 This is the fourth schematic diagram of the controllable shutdown hybrid grid phase-commutation converter in the embodiments of this application; Figure 5 This is one of the circuit diagrams of the controllable shutdown hybrid grid phase-commutation converter in the embodiments of this application; Figure 6 This is the second circuit diagram of the controllable shutdown hybrid grid phase-commutation converter in the embodiments of this application; Figure 7 This is the third circuit diagram of the controllable shutdown hybrid grid phase-commutation converter in the embodiments of this application; Figure 8 This is the fourth circuit diagram of the controllable shutdown hybrid grid phase-commutation converter in the embodiments of this application; Figure 9A This is one of the schematic diagrams of the valve structure in the embodiments of this application; Figure 9B This is the second schematic diagram of the valve structure in the embodiment of this application; Figure 9C This is the third schematic diagram of the valve structure in the embodiments of this application; Figure 9D This is the fourth schematic diagram of the valve structure in the embodiments of this application; Figure 9E This is the fifth schematic diagram of the valve structure in the embodiments of this application; Figure 9F This is the sixth schematic diagram of the valve structure in the embodiments of this application; Figure 9G This is the seventh schematic diagram of the valve structure in the embodiments of this application; Figure 9H This is the eighth schematic diagram of the valve structure in the embodiments of this application; Figure 9I This is the ninth schematic diagram of the valve structure in the embodiments of this application; Figure 9J This is the tenth schematic diagram of the valve structure in the embodiments of this application; Figure 9K This is eleventh of the schematic diagrams of the valve structure in the embodiments of this application; Figure 10 This is one of the schematic flowcharts of the control method for controllable shutdown of a hybrid grid phase-commutation converter according to an embodiment of this application; Figure 11 This is the second schematic diagram of the control method for controllable shutdown of hybrid grid phase-commutation converter in this application embodiment; Figure 12 This is the third schematic diagram of the control method for controllable shutdown of hybrid grid phase-commutation converter in this application embodiment; Figure 13 This is a schematic diagram illustrating the effect of a method for controlling the shutdown of a hybrid grid phase-commutation converter when it is energized and the main circuit is not unlocked, according to an embodiment of this application. Figure 14 This is a simulation diagram of the controllable shutdown hybrid grid phase converter of this application when it is energized and the main circuit is not unlocked; Figure 15 This is a block diagram of the control device for the controllable shutdown hybrid grid phase-commutator according to an embodiment of this application; Figure 16 This is a block diagram of a controllable shutdown hybrid grid phase-commutator system according to an embodiment of this application.

[0023] 1. Upper bridge arm circuit; 2. Lower bridge arm circuit; 3. Upper bridge transfer circuit; 4. Upper bridge turn-off circuit; 5. Lower bridge transfer circuit; 6. Lower bridge turn-off circuit; 20. Controllable turn-off hybrid grid phase-commutator control device; 201. First control module; 202. Second control module; 30. Controllable turn-off hybrid grid phase-commutator system; 301. Controllable turn-off hybrid grid phase-commutator. Detailed Implementation

[0024] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this application, "a plurality of" means two or more, unless otherwise explicitly specified.

[0026] This application provides a controllable shutdown hybrid grid phase-commutation converter, including a main circuit and an auxiliary circuit.

[0027] The main circuit includes at least one phase upper bridge arm circuit and at least one phase lower bridge arm circuit. One end of the at least one phase upper bridge arm circuit is connected to the anode bus of the main circuit, and the other end of the at least one phase upper bridge arm circuit is connected to one end of the at least one phase lower bridge arm circuit. The other end of the at least one phase lower bridge arm circuit is connected to the cathode bus of the main circuit.

[0028] In some embodiments, at least one upper bridge arm circuit and at least one lower bridge arm circuit each include: a first fully controlled valve, a first partially controlled valve, and a second partially controlled valve; the first fully controlled valve, the first partially controlled valve, and the second partially controlled valve are connected in series; one end of the first fully controlled valve of the at least one upper bridge arm circuit is connected to the anode bus of the main circuit, the other end of the first fully controlled valve of the at least one upper bridge arm circuit is connected to one end of the first partially controlled valve of the at least one upper bridge arm circuit, the other end of the first partially controlled valve of the at least one upper bridge arm circuit is connected to one end of the second partially controlled valve of the at least one upper bridge arm circuit, the other end of the second partially controlled valve of the at least one upper bridge arm circuit is connected to one end of the second partially controlled valve of the at least one lower bridge arm circuit, the other end of the second partially controlled valve of the at least one lower bridge arm circuit is connected to one end of the first partially controlled valve of the at least one lower bridge arm circuit, the other end of the first partially controlled valve of the at least one lower bridge arm circuit is connected to one end of the first fully controlled valve of the at least one lower bridge arm circuit, and the other end of the first fully controlled valve of the at least one lower bridge arm circuit is connected to the cathode bus of the main circuit; or; One end of the first half-controlled valve of at least one phase upper bridge arm circuit is connected to the anode bus of the main circuit; the other end of the first half-controlled valve of at least one phase upper bridge arm circuit is connected to one end of the first full-controlled valve of at least one phase upper bridge arm circuit; the other end of the first full-controlled valve of at least one phase upper bridge arm circuit is connected to one end of the second half-controlled valve of at least one phase upper bridge arm circuit; the other end of the second half-controlled valve of at least one phase upper bridge arm circuit is connected to one end of the second half-controlled valve of at least one phase lower bridge arm circuit; the other end of the second half-controlled valve of at least one phase lower bridge arm circuit is connected to one end of the first full-controlled valve of at least one phase lower bridge arm circuit; the other end of the first full-controlled valve of at least one phase lower bridge arm circuit is connected to one end of the first half-controlled valve of at least one phase lower bridge arm circuit; and the other end of the first half-controlled valve of at least one phase lower bridge arm circuit is connected to the cathode bus of the main circuit.

[0029] In some embodiments, such as Figure 1 As shown, the main circuit can be a three-phase six-arm circuit, including: three upper arm circuits 1 and three lower arm circuits 2. There is a one-to-one correspondence between the three upper arm circuits 1 and the three lower arm circuits 2, and each corresponding upper arm circuit 1 and lower arm circuit 2 corresponds to one phase. One end of each upper arm circuit 1 is connected to the anode bus of the main circuit, and the other end of each upper arm circuit 1 is connected to one end of its corresponding lower arm circuit 2. The other end of its corresponding lower arm circuit 2 is connected to the cathode bus of the main circuit. Each upper arm circuit 1 and lower arm circuit 2 includes a first fully controlled valve, a first partially controlled valve, and a second partially controlled valve. The first fully controlled valve, the first partially controlled valve, and the second partially controlled valve are connected in series. One end of the first fully controlled valve of each upper arm circuit 1 is connected to the anode bus of the main circuit, and one end of the second partially controlled valve of each upper arm circuit 1 is connected to one end of the second partially controlled valve of its corresponding lower arm circuit 2. One end of the first fully controlled valve of each lower arm circuit 2 is connected to the cathode bus of the main circuit.

[0030] In some embodiments, please refer to further details. Figure 1As shown, the upper bridge arm circuit 1 of phase A includes a first fully controlled valve V41, a first partially controlled valve V42, and a second partially controlled valve V43. The first fully controlled valve V41, the first partially controlled valve V42, and the second partially controlled valve V43 are connected in series. One end of the first fully controlled valve V41 is connected to the anode bus P1 of the main circuit, and one end of the second partially controlled valve V43 is connected to the lower bridge arm circuit 2 of phase A. The upper bridge arm circuit 1 of phase B includes a first fully controlled valve V61, a first partially controlled valve V62, and a second partially controlled valve V63. The first fully controlled valve V61, the first partially controlled valve V62, and the second partially controlled valve V43 are connected in series. The second semi-controlled valve V63 is connected in series. One end of the first fully controlled valve V61 is connected to the anode bus P1 of the main circuit, and one end of the second semi-controlled valve V63 is connected to the lower bridge arm circuit 2 of phase B. The upper bridge arm circuit 1 of phase C includes a first fully controlled valve V21, a first semi-controlled valve V22, and a second semi-controlled valve V23. The first fully controlled valve V21, the first semi-controlled valve V22, and the second semi-controlled valve V23 are connected in series. One end of the first fully controlled valve V21 is connected to the anode bus P1 of the main circuit, and one end of the second semi-controlled valve V23 is connected to the lower bridge arm circuit 2 of phase C.

[0031] Phase A lower bridge arm circuit 2 includes a first fully controlled valve V11, a first partially controlled valve V12, and a second partially controlled valve V13. These valves are connected in series. One end of the first fully controlled valve V11 is connected to the cathode bus N1 of the main circuit, and one end of the second partially controlled valve V13 is connected to one end of the second partially controlled valve V43 of Phase A upper bridge arm circuit 1. Phase B lower bridge arm circuit 2 includes a first fully controlled valve V31, a first partially controlled valve V32, and a second partially controlled valve V33. These valves are connected in series. V33 is connected in series. One end of the first fully controlled valve V31 is connected to the cathode bus N1 of the main circuit. One end of the second semi-controlled valve V33 is connected to one end of the second semi-controlled valve V63 of the upper bridge arm circuit 1 of phase B. The lower bridge arm circuit 2 of phase C includes a first fully controlled valve V51, a first semi-controlled valve V52, and a second semi-controlled valve V53. The first fully controlled valve V51, the first semi-controlled valve V52, and the second semi-controlled valve V53 are connected in series. One end of the first fully controlled valve V51 is connected to the cathode bus N1 of the main circuit. One end of the second semi-controlled valve V53 is connected to the second semi-controlled valve V23 of the upper bridge arm circuit 1 of phase C.

[0032] The auxiliary circuit includes at least one phase upper bridge transfer circuit, one upper bridge turn-off circuit, at least one phase lower bridge transfer circuit, and one lower bridge turn-off circuit. One end of the at least one phase upper bridge transfer circuit is connected to the anode bus of the upper bridge transfer circuit, and the other end of the at least one phase upper bridge transfer circuit is connected to the at least one phase upper bridge arm circuit. One end of the upper bridge turn-off circuit is connected to the anode bus of the main circuit, and the other end of the upper bridge turn-off circuit is connected to the anode bus of the upper bridge transfer circuit. One end of the at least one phase lower bridge transfer circuit is connected to the cathode bus of the lower bridge transfer circuit, and the other end of the at least one phase lower bridge transfer circuit is connected to the at least one phase lower bridge arm circuit. One end of the lower bridge turn-off circuit is connected to the cathode bus of the main circuit, and the other end of the lower bridge turn-off circuit is connected to the cathode bus of the lower bridge transfer circuit.

[0033] Both the upper bridge transfer circuit and the lower bridge transfer circuit include: a third semi-controlled valve and / or a first uncontrolled valve; one end of the third semi-controlled valve and / or the first uncontrolled valve of the upper bridge transfer circuit is connected to the anode bus of the upper bridge transfer circuit; when one end of the first semi-controlled valve of the upper bridge arm circuit is connected to one end of the second semi-controlled valve, the other end of the third semi-controlled valve and / or the first uncontrolled valve of the upper bridge transfer circuit is connected to the connection point between the first semi-controlled valve and the second semi-controlled valve of the upper bridge arm circuit; or, when one end of the first fully controlled valve of the upper bridge arm circuit is connected to one end of the second semi-controlled valve, the other end of the third semi-controlled valve and / or the first uncontrolled valve of the upper bridge transfer circuit is connected to the connection point between the first fully controlled valve and the second semi-controlled valve of the upper bridge arm circuit. One end of the third half-controlled valve and / or the first uncontrolled valve of at least one phase downbridge transfer circuit is connected to the cathode bus of the downbridge transfer circuit. When one end of the first half-controlled valve of at least one phase downbridge arm circuit is connected to one end of the second half-controlled valve, the other end of the third half-controlled valve and / or the first uncontrolled valve of at least one phase downbridge transfer circuit is connected to the connection point between the first half-controlled valve and the second half-controlled valve of at least one phase downbridge arm circuit; or, when one end of the first fully controlled valve of at least one phase downbridge arm circuit is connected to one end of the second half-controlled valve, the other end of the third half-controlled valve and / or the first uncontrolled valve of at least one phase downbridge transfer circuit is connected to the connection point between the first fully controlled valve and the second half-controlled valve of at least one phase downbridge arm circuit.

[0034] In some embodiments, please refer to further details. Figure 1As shown, the auxiliary circuit includes: three upper bridge transfer circuits 3, one upper bridge shutdown circuit 4, three lower bridge transfer circuits 5, and one lower bridge shutdown circuit 6; wherein, the three upper bridge transfer circuits 3 correspond one-to-one with the three upper bridge arm circuits 1, the three lower bridge transfer circuits 5 correspond one-to-one with the three lower bridge arm circuits 2, the upper bridge shutdown circuit 4 corresponds to the three upper bridge arm circuits 1, and the lower bridge shutdown circuit 6 corresponds to the three lower bridge arm circuits 2; one end of each upper bridge transfer circuit 3 is connected to the anode bus of the upper bridge transfer circuit, and the other end of each upper bridge transfer circuit 3 is connected to its corresponding upper bridge arm circuit 1; one end of the upper bridge shutdown circuit 4 is connected to the anode bus of the main circuit, and the other end of the upper bridge shutdown circuit 4 is connected to the anode bus of the upper bridge transfer circuit; one end of each lower bridge transfer circuit 5 is connected to the cathode bus of the lower bridge transfer circuit, and the other end of each lower bridge transfer circuit 5 is connected to its corresponding lower bridge arm circuit 2; one end of the lower bridge shutdown circuit 6 is connected to the cathode bus of the main circuit, and the other end of the lower bridge shutdown circuit 6 is connected to the cathode bus of the lower bridge transfer circuit.

[0035] In some embodiments, the upper bridge shutdown circuit 4 of the auxiliary circuit and the anode bus of the main circuit are connected by a disconnecting switch and / or a knife switch, and the lower bridge shutdown circuit 6 of the auxiliary circuit and the cathode bus of the main circuit are connected by a disconnecting switch and / or a knife switch.

[0036] Each upper bridge transfer circuit 3 and each lower bridge transfer circuit 5 includes: a third semi-controlled valve and / or a first uncontrolled valve; one end of the third semi-controlled valve and / or the first uncontrolled valve of each upper bridge transfer circuit 3 is connected to the anode bus of the upper bridge transfer circuit, and the other end of the third semi-controlled valve and / or the first uncontrolled valve of each upper bridge transfer circuit 3 is connected to the connection point between the first semi-controlled valve and the second semi-controlled valve of its corresponding upper bridge arm circuit 1; one end of the third semi-controlled valve and / or the first uncontrolled valve of each lower bridge transfer circuit 5 is connected to the cathode bus of the lower bridge transfer circuit, and the other end of the third semi-controlled valve or the first uncontrolled valve of each lower bridge transfer circuit 5 is connected to the connection point between the first semi-controlled valve and the second semi-controlled valve of its corresponding lower bridge arm circuit 2, wherein the first semi-controlled valve, the second semi-controlled valve and the third semi-controlled valve all include a semi-controlled switch, and the first uncontrolled valve includes an uncontrolled switch; the withstand pressure ratio of the first semi-controlled valve and the second semi-controlled valve ranges from 0.1 to 10.

[0037] In some embodiments, please refer to further details. Figure 1As shown, the A-phase upper bridge transfer circuit 3 includes a third semi-controlled valve and / or a first uncontrolled valve V44. One end of the third semi-controlled valve and / or the first uncontrolled valve V44 is connected to the anode bus P2 of the upper bridge transfer circuit, and the other end of the third semi-controlled valve and / or the first uncontrolled valve V44 is connected to the connection point of the first semi-controlled valve V42 and the second semi-controlled valve V43 of the A-phase upper bridge arm circuit 1. The B-phase upper bridge transfer circuit 3 includes a third semi-controlled valve and / or a first uncontrolled valve V64. One end of the third semi-controlled valve and / or the first uncontrolled valve V64 is connected to the anode bus P2 of the upper bridge transfer circuit. Line P2 is connected, and the other end of the third semi-controlled valve and / or the first uncontrolled valve V64 is connected to the connection point of the first semi-controlled valve V62 and the second semi-controlled valve V63 of the upper bridge arm circuit 1 of phase B; the upper bridge transfer circuit 3 of phase C includes a third semi-controlled valve and / or the first uncontrolled valve V24, one end of the third semi-controlled valve and / or the first uncontrolled valve V24 is connected to the anode bus P2 of the upper bridge transfer circuit, and the other end of the third semi-controlled valve and / or the first uncontrolled valve V24 is connected to the connection point of the first semi-controlled valve V22 and the second semi-controlled valve V23 of the upper bridge arm circuit 1 of phase C.

[0038] Phase A downbridge transfer circuit 5 includes a third semi-controlled valve and / or a first uncontrolled valve V14. One end of the third semi-controlled valve and / or the first uncontrolled valve V14 is connected to the cathode bus N2 of the downbridge transfer circuit, and the other end of the third semi-controlled valve and / or the first uncontrolled valve V14 is connected to the connection point of the first semi-controlled valve V12 and the second semi-controlled valve V13 of the phase A downbridge arm circuit 2. Phase B downbridge transfer circuit 5 includes a third semi-controlled valve and / or a first uncontrolled valve V34. One end of the third semi-controlled valve and / or the first uncontrolled valve V34 is connected to the cathode bus of the downbridge transfer circuit. N2 is connected, and the other end of the third semi-controlled valve and / or the first uncontrolled valve V34 is connected to the connection point of the first semi-controlled valve V32 and the second semi-controlled valve V33 of the B-phase lower bridge arm circuit 2; the C-phase lower bridge transfer circuit 5 includes a third semi-controlled valve and / or the first uncontrolled valve V54, one end of the third semi-controlled valve and / or the first uncontrolled valve V54 is connected to the cathode bus N2 of the lower bridge transfer circuit, and the other end of the third semi-controlled valve and / or the first uncontrolled valve V54 is connected to the connection point of the first semi-controlled valve V52 and the second semi-controlled valve V53 of the C-phase lower bridge arm circuit 2.

[0039] In some embodiments, both the upper bridge shutdown circuit and the lower bridge shutdown circuit include a second fully controlled valve; one end of the second fully controlled valve of the upper bridge shutdown circuit is connected to the anode bus of the main circuit, and the other end of the second fully controlled valve of the upper bridge shutdown circuit is connected to the anode bus of the upper bridge transfer circuit; one end of the second fully controlled valve of the lower bridge shutdown circuit is connected to the cathode bus of the main circuit, and the other end of the second fully controlled valve of the lower bridge shutdown circuit is connected to the cathode bus of the lower bridge transfer circuit.

[0040] In some embodiments, please refer to further details. Figure 1As shown, both the upper bridge shutdown circuit 4 and the lower bridge shutdown circuit 6 include a second full control valve; one end of the second full control valve of the upper bridge shutdown circuit 4 is connected to the anode bus of the main circuit, and the other end of the second full control valve of the upper bridge shutdown circuit 4 is connected to the anode bus of the upper bridge transfer circuit; one end of the second full control valve of the lower bridge shutdown circuit 6 is connected to the cathode bus of the main circuit, and the other end of the second full control valve of the lower bridge shutdown circuit 6 is connected to the cathode bus of the lower bridge transfer circuit; wherein, the first full control valve and the second full control valve include at least one of a one-way full control switch, a two-way full control switch, and a submodule series switch.

[0041] In some embodiments, please refer to further details. Figure 1 As shown, the upper bridge shutdown circuit 4 includes a second full control valve V71. One end of the second full control valve V71 is connected to the anode bus P1 of the main circuit, and the other end of the second full control valve V71 is connected to the anode bus P2 of the upper bridge transfer circuit. The lower bridge shutdown circuit 6 includes a second full control valve V72. One end of the second full control valve V72 is connected to the cathode bus N1 of the main circuit, and the other end of the second full control valve V72 is connected to the cathode bus N2 of the lower bridge transfer circuit. Phases A, B, and C share the upper bridge shutdown circuit 4 and the lower bridge shutdown circuit 6.

[0042] In some embodiments, at least one phase upper arm circuit and at least one phase lower arm circuit each include: a first semi-controlled valve and a second semi-controlled valve; the first semi-controlled valve and the second semi-controlled valve are connected in series; one end of the first semi-controlled valve of the at least one phase upper arm circuit is connected to the anode bus of the main circuit, the other end of the first semi-controlled valve of the at least one phase upper arm circuit is connected to one end of the second semi-controlled valve of the at least one phase upper arm circuit, the other end of the second semi-controlled valve of the at least one phase upper arm circuit is connected to one end of the second semi-controlled valve of the at least one phase lower arm circuit, the other end of the second semi-controlled valve of the at least one phase lower arm circuit is connected to one end of the first semi-controlled valve of the at least one phase lower arm circuit, and the other end of the first semi-controlled valve of the at least one phase lower arm circuit is connected to the cathode bus of the main circuit.

[0043] In some embodiments, such as Figure 2As shown, the upper bridge arm circuit 1 of phase A includes a first half-control valve V42 and a second half-control valve V43, which are connected in series. One end of the first half-control valve V42 is connected to the anode bus P1 of the main circuit, and one end of the second half-control valve V43 is connected to the lower bridge arm circuit 2 of phase A. The upper bridge arm circuit 1 of phase B includes a first half-control valve V62 and a second half-control valve V63, which are connected in series. One end of the first half-control valve V62 is connected to the anode bus P1 of the main circuit, and one end of the second half-control valve V63 is connected to the lower bridge arm circuit 2 of phase B. The upper bridge arm circuit 1 of phase C includes a first half-control valve V22 and a second half-control valve V23, which are connected in series. One end of the first half-control valve V22 is connected to the anode bus P1 of the main circuit, and one end of the second half-control valve V23 is connected to the lower bridge arm circuit 2 of phase C.

[0044] Phase A lower bridge arm circuit 2 includes a first semi-controlled valve V12 and a second semi-controlled valve V13, which are connected in series. One end of the first semi-controlled valve V12 is connected to the cathode bus N1 of the main circuit, and one end of the second semi-controlled valve V13 is connected to one end of the second semi-controlled valve V43 of Phase A upper bridge arm circuit 1. Phase B lower bridge arm circuit 2 includes a first semi-controlled valve V32 and a second semi-controlled valve V33, which are connected in series. One end of the semi-controlled valve V32 is connected to the cathode bus N1 of the main circuit, and one end of the second semi-controlled valve V33 is connected to one end of the second semi-controlled valve V63 of the upper bridge arm circuit 1 of phase B; the lower bridge arm circuit 2 of phase C includes a first semi-controlled valve V52 and a second semi-controlled valve V53, which are connected in series. One end of the first semi-controlled valve V52 is connected to the cathode bus N1 of the main circuit, and one end of the second semi-controlled valve V53 is connected to the second semi-controlled valve V23 of the upper bridge arm circuit 1 of phase C.

[0045] In some embodiments, please refer to further details. Figure 2As shown, the A-phase upper bridge transfer circuit 3 includes a third semi-controlled valve and / or a first uncontrolled valve V44. One end of the third semi-controlled valve and / or the first uncontrolled valve V44 is connected to the anode bus P2 of the upper bridge transfer circuit, and the other end of the third semi-controlled valve and / or the first uncontrolled valve V44 is connected to the connection point of the first semi-controlled valve V42 and the second semi-controlled valve V43 of the A-phase upper bridge arm circuit 1. The B-phase upper bridge transfer circuit 3 includes a third semi-controlled valve and / or a first uncontrolled valve V64. One end of the third semi-controlled valve and / or the first uncontrolled valve V64 is connected to the anode bus P2 of the upper bridge transfer circuit. Line P2 is connected, and the other end of the third semi-controlled valve and / or the first uncontrolled valve V64 is connected to the connection point of the first semi-controlled valve V62 and the second semi-controlled valve V63 of the upper bridge arm circuit 1 of phase B; the upper bridge transfer circuit 3 of phase C includes a third semi-controlled valve and / or the first uncontrolled valve V24, one end of the third semi-controlled valve and / or the first uncontrolled valve V24 is connected to the anode bus P2 of the upper bridge transfer circuit, and the other end of the third semi-controlled valve and / or the first uncontrolled valve V24 is connected to the connection point of the first semi-controlled valve V22 and the second semi-controlled valve V23 of the upper bridge arm circuit 1 of phase C.

[0046] Phase A downbridge transfer circuit 5 includes a third semi-controlled valve and / or a first uncontrolled valve V14. One end of the third semi-controlled valve and / or the first uncontrolled valve V14 is connected to the cathode bus N2 of the downbridge transfer circuit, and the other end of the third semi-controlled valve and / or the first uncontrolled valve V14 is connected to the connection point of the first semi-controlled valve V12 and the second semi-controlled valve V13 of the phase A downbridge arm circuit 2. Phase B downbridge transfer circuit 5 includes a third semi-controlled valve and / or a first uncontrolled valve V34. One end of the third semi-controlled valve and / or the first uncontrolled valve V34 is connected to the cathode bus of the downbridge transfer circuit. N2 is connected, and the other end of the third semi-controlled valve and / or the first uncontrolled valve V34 is connected to the connection point of the first semi-controlled valve V32 and the second semi-controlled valve V33 of the B-phase lower bridge arm circuit 2; the C-phase lower bridge transfer circuit 5 includes a third semi-controlled valve and / or the first uncontrolled valve V54, one end of the third semi-controlled valve and / or the first uncontrolled valve V54 is connected to the cathode bus N2 of the lower bridge transfer circuit, and the other end of the third semi-controlled valve and / or the first uncontrolled valve V54 is connected to the connection point of the first semi-controlled valve V52 and the second semi-controlled valve V53 of the C-phase lower bridge arm circuit 2.

[0047] In some embodiments, please refer to further details. Figure 2 As shown, the upper bridge shutdown circuit 4 includes a second full control valve V71. One end of the second full control valve V71 is connected to the anode bus P1 of the main circuit, and the other end of the second full control valve V71 is connected to the anode bus P2 of the upper bridge transfer circuit. The lower bridge shutdown circuit 6 includes a second full control valve V72. One end of the second full control valve V72 is connected to the cathode bus N1 of the main circuit, and the other end of the second full control valve V72 is connected to the cathode bus N2 of the lower bridge transfer circuit. Phases A, B, and C share the upper bridge shutdown circuit 4 and the lower bridge shutdown circuit 6.

[0048] In some embodiments, at least one upper bridge arm circuit and at least one lower bridge arm circuit each include: a first fully controlled valve and a first partially controlled valve; the first fully controlled valve and the first partially controlled valve are connected in series; one end of the first fully controlled valve of the at least one upper bridge arm circuit is connected to the anode bus of the main circuit, the other end of the first fully controlled valve of the at least one upper bridge arm circuit is connected to one end of the first partially controlled valve of the at least one upper bridge arm circuit, the other end of the first partially controlled valve of the at least one upper bridge arm circuit is connected to one end of the first partially controlled valve of the at least one lower bridge arm circuit, the other end of the first partially controlled valve of the at least one lower bridge arm circuit is connected to one end of the first fully controlled valve of the at least one lower bridge arm circuit, and the other end of the first fully controlled valve of the at least one lower bridge arm circuit is connected to the cathode bus of the main circuit; or; One end of the first half-controlled valve of at least one phase upper bridge arm circuit is connected to the anode bus of the main circuit, the other end of the first half-controlled valve of at least one phase upper bridge arm circuit is connected to one end of the first full-controlled valve of at least one phase upper bridge arm circuit, the other end of the first full-controlled valve of at least one phase upper bridge arm circuit is connected to one end of the first full-controlled valve of at least one phase lower bridge arm circuit, the other end of the first full-controlled valve of at least one phase lower bridge arm circuit is connected to one end of the first half-controlled valve of at least one phase lower bridge arm circuit, and the other end of the first half-controlled valve of at least one phase lower bridge arm circuit is connected to the cathode bus of the main circuit.

[0049] In some embodiments, such as Figure 3 As shown, the upper bridge arm circuit 1 of phase A includes a first fully controlled valve V41 and a first partially controlled valve V42, which are connected in series. One end of the first fully controlled valve V41 is connected to the anode bus P1 of the main circuit, and one end of the first partially controlled valve V42 is connected to the lower bridge arm circuit 2 of phase A. The upper bridge arm circuit 1 of phase B includes a first fully controlled valve V61 and a first partially controlled valve V62, which are connected in series. One end of the first fully controlled valve V61 is connected to the anode bus P1 of the main circuit, and one end of the first partially controlled valve V62 is connected to the lower bridge arm circuit 2 of phase B. The upper bridge arm circuit 1 of phase C includes a first fully controlled valve V21 and a first partially controlled valve V22, which are connected in series. One end of the first fully controlled valve V21 is connected to the anode bus P1 of the main circuit, and one end of the first partially controlled valve V22 is connected to the lower bridge arm circuit 2 of phase C.

[0050] Phase A lower bridge arm circuit 2 includes a first fully controlled valve V11 and a first partially controlled valve V12, which are connected in series. One end of the first fully controlled valve V11 is connected to the cathode bus N1 of the main circuit, and one end of the first partially controlled valve V12 is connected to one end of the first partially controlled valve V42 of Phase A upper bridge arm circuit 1. Phase B lower bridge arm circuit 2 includes a first fully controlled valve V31 and a first partially controlled valve V32, which are connected in series. One end of a fully controlled valve V31 is connected to the cathode bus N1 of the main circuit, and one end of a first semi-controlled valve V32 is connected to one end of the first semi-controlled valve V62 of the upper bridge arm circuit 1 of phase B. The lower bridge arm circuit 2 of phase C includes a first fully controlled valve V51 and a first semi-controlled valve V52, which are connected in series. One end of the first fully controlled valve V51 is connected to the cathode bus N1 of the main circuit, and one end of the first semi-controlled valve V52 is connected to the first semi-controlled valve V22 of the upper bridge arm circuit 1 of phase C.

[0051] In some embodiments, please refer to further details. Figure 3 As shown, the A-phase upper bridge transfer circuit 3 includes a third semi-controlled valve and / or a first uncontrolled valve V44. One end of the third semi-controlled valve and / or the first uncontrolled valve V44 is connected to the anode bus P2 of the upper bridge transfer circuit, and the other end of the third semi-controlled valve and / or the first uncontrolled valve V44 is connected to one end of the first semi-controlled valve V42 of the A-phase upper bridge arm circuit 1. The B-phase upper bridge transfer circuit 3 includes a third semi-controlled valve and / or a first uncontrolled valve V64. One end of the third semi-controlled valve and / or the first uncontrolled valve V64 is connected to the upper bridge transfer circuit 1. The anode bus P2 of the transfer circuit is connected, and the other end of the third semi-controlled valve and / or the first uncontrolled valve V64 is connected to one end of the first semi-controlled valve V62 of the upper bridge arm circuit 1 of phase B; the upper bridge transfer circuit 3 of phase C includes a third semi-controlled valve and / or the first uncontrolled valve V24, one end of the third semi-controlled valve and / or the first uncontrolled valve V24 is connected to the anode bus P2 of the upper bridge transfer circuit, and the other end of the third semi-controlled valve and / or the first uncontrolled valve V24 is connected to one end of the first semi-controlled valve V22 of the upper bridge arm circuit 1 of phase C.

[0052] Phase A downbridge transfer circuit 5 includes a third semi-controlled valve and / or a first uncontrolled valve V14. One end of the third semi-controlled valve and / or the first uncontrolled valve V14 is connected to the cathode bus N2 of the downbridge transfer circuit, and the other end of the third semi-controlled valve and / or the first uncontrolled valve V14 is connected to one end of the first semi-controlled valve V12 of the phase A downbridge arm circuit 2. Phase B downbridge transfer circuit 5 includes a third semi-controlled valve and / or a first uncontrolled valve V34. One end of the third semi-controlled valve and / or the first uncontrolled valve V34 is connected to the cathode bus N2 of the downbridge transfer circuit. The cathode bus N2 is connected to the circuit, and the other end of the third semi-controlled valve and / or the first uncontrolled valve V34 is connected to one end of the first semi-controlled valve V32 of the lower bridge arm circuit 2 of phase B; the lower bridge transfer circuit 5 of phase C includes a third semi-controlled valve and / or the first uncontrolled valve V54, one end of the third semi-controlled valve and / or the first uncontrolled valve V54 is connected to the cathode bus N2 of the lower bridge transfer circuit, and the other end of the third semi-controlled valve and / or the first uncontrolled valve V54 is connected to one end of the first semi-controlled valve V52 of the lower bridge arm circuit 2 of phase C.

[0053] In some embodiments, please refer to further details. Figure 3 As shown, the upper bridge shutdown circuit 4 includes a second full control valve V71. One end of the second full control valve V71 is connected to the anode bus P1 of the main circuit, and the other end of the second full control valve V71 is connected to the anode bus P2 of the upper bridge transfer circuit. The lower bridge shutdown circuit 6 includes a second full control valve V72. One end of the second full control valve V72 is connected to the cathode bus N1 of the main circuit, and the other end of the second full control valve V72 is connected to the cathode bus N2 of the lower bridge transfer circuit. Phases A, B, and C share the upper bridge shutdown circuit 4 and the lower bridge shutdown circuit 6.

[0054] In some embodiments, at least one phase upper arm circuit and at least one phase lower arm circuit each include: a first semi-controlled valve; one end of the first semi-controlled valve of the at least one phase upper arm circuit is connected to the anode bus of the main circuit, the other end of the first semi-controlled valve of the at least one phase upper arm circuit is connected to one end of the first semi-controlled valve of the at least one phase lower arm circuit, and the other end of the first semi-controlled valve of the at least one phase lower arm circuit is connected to the cathode bus of the main circuit.

[0055] In some embodiments, such as Figure 4 As shown, the upper bridge arm circuit 1 of phase A includes a first semi-controlled valve V42, one end of which is connected to the anode bus P1 of the main circuit, and the other end of which is connected to the lower bridge arm circuit 2 of phase A; the upper bridge arm circuit 1 of phase B includes a first semi-controlled valve V62, one end of which is connected to the anode bus P1 of the main circuit, and the other end of which is connected to the lower bridge arm circuit 2 of phase B; the upper bridge arm circuit 1 of phase C includes a first semi-controlled valve V22, one end of which is connected to the anode bus P1 of the main circuit, and the other end of which is connected to the lower bridge arm circuit 2 of phase C.

[0056] Phase A lower bridge arm circuit 2 includes a first semi-controlled valve V12, one end of which is connected to the main circuit cathode bus N1, and the other end of which is connected to one end of Phase A upper bridge arm circuit 1; Phase B lower bridge arm circuit 2 includes a first semi-controlled valve V32, one end of which is connected to the main circuit cathode bus N1, and the other end of which is connected to one end of Phase B upper bridge arm circuit 1; Phase C lower bridge arm circuit 2 includes a first semi-controlled valve V52, one end of which is connected to the main circuit cathode bus N1, and the other end of which is connected to Phase C upper bridge arm circuit 1.

[0057] In some embodiments, please refer to further details. Figure 4 As shown, the A-phase upper bridge transfer circuit 3 includes a third semi-controlled valve and / or a first uncontrolled valve V44. One end of the third semi-controlled valve and / or the first uncontrolled valve V44 is connected to the anode bus P2 of the upper bridge transfer circuit, and the other end of the third semi-controlled valve and / or the first uncontrolled valve V44 is connected to one end of the first semi-controlled valve V42 of the A-phase upper bridge arm circuit 1; the B-phase upper bridge transfer circuit 3 includes a third semi-controlled valve and / or a first uncontrolled valve V64, and the third semi-controlled valve and / or the first uncontrolled valve V64... One end of 4 is connected to the anode bus P2 of the upper bridge transfer circuit, and the other end of the third semi-controlled valve and / or the first uncontrolled valve V64 is connected to one end of the upper bridge arm circuit 1 of phase B; the upper bridge transfer circuit 3 of phase C includes a third semi-controlled valve and / or the first uncontrolled valve V24, one end of the third semi-controlled valve and / or the first uncontrolled valve V24 is connected to the anode bus P2 of the upper bridge transfer circuit, and the other end of the third semi-controlled valve and / or the first uncontrolled valve V24 is connected to one end of the upper bridge arm circuit 1 of phase C.

[0058] Phase A downbridge transfer circuit 5 includes a third semi-controlled valve and / or a first uncontrolled valve V14. One end of the third semi-controlled valve and / or the first uncontrolled valve V14 is connected to the cathode bus N2 of the downbridge transfer circuit, and the other end of the third semi-controlled valve and / or the first uncontrolled valve V14 is connected to one end of the phase A downbridge arm circuit 2. Phase B downbridge transfer circuit 5 includes a third semi-controlled valve and / or a first uncontrolled valve V34. One end of the third semi-controlled valve and / or the first uncontrolled valve V34 is connected to the cathode bus N2 of the downbridge transfer circuit, and the other end of the third semi-controlled valve and / or the first uncontrolled valve V34 is connected to one end of the phase B downbridge arm circuit 2. Phase C downbridge transfer circuit 5 includes a third semi-controlled valve and / or a first uncontrolled valve V54. One end of the third semi-controlled valve and / or the first uncontrolled valve V54 is connected to the cathode bus N2 of the downbridge transfer circuit, and the other end of the third semi-controlled valve and / or the first uncontrolled valve V54 is connected to one end of the phase C downbridge arm circuit 2.

[0059] In some embodiments, please refer to further details. Figure 4As shown, the upper bridge shutdown circuit 4 includes a second full control valve V71. One end of the second full control valve V71 is connected to the anode bus P1 of the main circuit, and the other end of the second full control valve V71 is connected to the anode bus P2 of the upper bridge transfer circuit. The lower bridge shutdown circuit 6 includes a second full control valve V72. One end of the second full control valve V72 is connected to the cathode bus N1 of the main circuit, and the other end of the second full control valve V72 is connected to the cathode bus N2 of the lower bridge transfer circuit. Phases A, B, and C share the upper bridge shutdown circuit 4 and the lower bridge shutdown circuit 6.

[0060] like Figure 5 As shown, based on Figure 1 The topology diagram shows that each first fully controlled valve and each second fully controlled valve uses at least one IGBT (Insulated Gate Bipolar Transistor) for its unidirectional fully controlled switch. The system is composed of multiple IGBTs connected in series. The half-controlled switches of each first half-controlled valve, each second half-controlled valve, and each third half-controlled valve are composed of at least one thyristor connected in series. The positions of the first fully controlled valve and the first half-controlled valve can be interchanged. For example, the one-way fully controlled switches of the first fully controlled valve V41 of the upper bridge arm circuit of phase A, the second fully controlled valve V71 of the upper bridge turn-off circuit, the first fully controlled valve V11 of the lower bridge arm circuit of phase A, and the second fully controlled valve V72 of the lower bridge turn-off circuit are all composed of multiple IGBTs connected in series. The first half-controlled valves V42 and V43 of the upper bridge arm circuit of phase A, and the first half-controlled valves V12 and V13 of the lower bridge arm circuit of phase A are all composed of multiple thyristors connected in series. The half-controlled switches of the third half-controlled valve V44 of the upper bridge transfer circuit of phase A and the third half-controlled valve V14 of the lower bridge transfer circuit of phase A are all composed of multiple thyristors connected in series.

[0061] In addition, the one-way full control switch of the first full control valve corresponding to phases B and C is the same as the one-way full control switch of the first full control valve corresponding to phase A; the half control switches of the first and second half control valves corresponding to phases B and C are the same as the half control switches of the first and second half control valves corresponding to phase A; and the half control switches of the third half control valves corresponding to phases B and C are the same as the half control switches of the third half control valve corresponding to phase A.

[0062] In some embodiments, in order to absorb the energy when the first fully controlled valve and the second fully controlled valve are shut off, surge arresters are connected in parallel across the first fully controlled valve and the second fully controlled valve, respectively. Simultaneously, the surge arresters also protect the first fully controlled valve, the second fully controlled valve, the first partially controlled valve, the second partially controlled valve, and the first uncontrolled valve from lightning strikes, operational interruptions, and power frequency overvoltages.

[0063] like Figure 6 As shown, based on Figure 2The topology diagram shows that the unidirectional full control switch and submodule series switch of each second full control valve are composed of at least one IGBT and at least one full-bridge submodule connected in series. The half control switch of each first half control valve, each second half control valve, and each third half control valve is composed of at least one thyristor connected in series. The positions of the first full control valve and the first half control valve can be interchanged. For example, the unidirectional full control switch and submodule series switch of the second full control valve V71 in the upper bridge shutdown circuit and the second full control valve V72 in the lower bridge shutdown circuit are composed of multiple IGBTs and full-bridge submodules connected in series. The first half control valve V42 and the second half control valve V43 in the upper bridge arm circuit of phase A, and the first half control valve V12 and the second half control valve V13 in the lower bridge arm circuit of phase A are composed of multiple thyristors connected in series. The half control switch of the third half control valve V44 in the upper bridge transfer circuit of phase A and the third half control valve V14 in the lower bridge transfer circuit of phase A are composed of multiple thyristors connected in series.

[0064] In addition, the one-way full control switch and sub-module series switch of the second full control valve corresponding to phases B and C are the same as the one-way full control switch and sub-module series switch of the second full control valve corresponding to phase A; the half control switches of the first and second half control valves corresponding to phases B and C are the same as the half control switches of the first and second half control valves corresponding to phase A; and the half control switches of the third half control valves corresponding to phases B and C are the same as the half control switches of the third half control valve corresponding to phase A.

[0065] like Figure 7 As shown, based on Figure 3 The topology diagram shows that the unidirectional full control switch for each first full control valve and each second full control valve is composed of at least one insulated gate bipolar transistor (IGBT) connected in series, and the half control switch for each first half control valve and each third half control valve is composed of at least one thyristor connected in series. The positions of the first full control valves and the first half control valves can be interchanged. For example, the unidirectional full control switches for the first full control valve V41 in the A-phase upper bridge arm circuit, the second full control valve V71 in the upper bridge turn-off circuit, the first full control valve V11 in the A-phase lower bridge arm circuit, and the second full control valve V72 in the lower bridge turn-off circuit are all composed of multiple IGBTs connected in series; the first half control valve V42 in the A-phase upper bridge arm circuit and the first half control valve V12 in the A-phase lower bridge arm circuit are both composed of multiple thyristors connected in series; and the half control switches for the third half control valve V44 in the A-phase upper bridge transfer circuit and the third half control valve V14 in the A-phase lower bridge transfer circuit are both composed of multiple thyristors connected in series.

[0066] In addition, the one-way full control switch of the first full control valve corresponding to phases B and C is the same as the one-way full control switch of the first full control valve corresponding to phase A; the half control switch of the first half control valve corresponding to phases B and C is the same as the half control switch of the first half control valve corresponding to phase A; and the half control switch of the third half control valve corresponding to phases B and C is the same as the half control switch of the third half control valve corresponding to phase A.

[0067] like Figure 8 As shown, based on Figure 4 The topology diagram shows that the unidirectional full control switch and submodule series switch of each second full control valve are composed of at least one IGBT and at least one full-bridge submodule connected in series. The half control switch of each first half control valve and each third half control valve is composed of at least one thyristor connected in series. For example, the full control switches of the second full control valve V71 in the upper bridge turn-off circuit and the second full control valve V72 in the lower bridge turn-off circuit are composed of multiple full-bridge submodules and multiple IGBTs connected in series. The first half control valve V42 in the upper bridge arm circuit of phase A and the first half control valve V12 in the lower bridge arm circuit of phase A are composed of multiple thyristors connected in series. The half control switches of the third half control valve V44 in the upper bridge transfer circuit of phase A and the third half control valve V14 in the lower bridge transfer circuit of phase A are composed of multiple thyristors connected in series.

[0068] In addition, the one-way full control switch and sub-module series switch of the second full control valve corresponding to phases B and C are the same as the one-way full control switch and sub-module series switch of the second full control valve corresponding to phase A; the half control switch of the first half control valve corresponding to phases B and C are the same as the half control switch of the first half control valve corresponding to phase A; and the half control switch of the third half control valve corresponding to phases B and C are the same as the half control switch of the third half control valve corresponding to phase A.

[0069] In some embodiments, in order to enable the first fully controlled valve to have reverse pressure resistance, the first fully controlled valve is connected in series with a second uncontrolled valve; in order to prevent the first fully controlled valve from being overpressured, a fourth semi-controlled valve is connected in parallel across the two ends of the first fully controlled valve, or a fourth semi-controlled valve is connected in parallel across the two ends of the first fully controlled valve and the second uncontrolled valve connected in series, the fourth semi-controlled valve including a semi-controlled switch; the second uncontrolled valve including an uncontrolled switch.

[0070] In some embodiments, if the upper bridge transfer circuit and the lower bridge transfer circuit use a first uncontrolled valve, and the second half-controlled valve of the upper bridge arm circuit and the lower bridge arm circuit, and the second fully controlled valve of the upper bridge shutdown circuit and the lower bridge shutdown circuit cannot withstand the positive voltage of the bridge arm, the upper bridge shutdown circuit and the lower bridge shutdown circuit also include a fifth half-controlled valve, the fifth half-controlled valve and the second fully controlled valve are connected in series, and the fifth half-controlled valve includes a half-controlled switch for bearing part of the positive voltage.

[0071] In some embodiments, the first fully controlled valve, and / or the first partially controlled valve, and / or the second partially controlled valve, and / or the third partially controlled valve, and / or the first uncontrolled valve further includes a reactor.

[0072] In some embodiments, the peak value of the continuous operating voltage of the first fully controlled valve is 0.01 to 0.2 times the peak value of the continuous operating voltage of the upper or lower bridge arm circuit, the peak value of the continuous operating voltage of the first semi-controlled valve is 0.2 to 0.8 times the peak value of the continuous operating voltage of the upper or lower bridge arm circuit, and the peak value of the continuous operating voltage of the second semi-controlled valve is 0.2 to 0.8 times the peak value of the continuous operating voltage of the upper or lower bridge arm circuit.

[0073] In some embodiments, a fully controlled switch includes at least one fully controlled device connected in series, the fully controlled device including at least one integrated gate commutated thyristor (IGCT), IGBT, gate turn-off thyristor (GTO), and metal-oxide-semiconductor field-effect transistor (MOSFET); a semi-controlled switch includes at least one semi-controlled device connected in series, the semi-controlled device including a thyristor; and an uncontrolled switch includes at least one uncontrolled device connected in series, the uncontrolled device including a diode.

[0074] like Figure 9A As shown, the uncontrolled switch includes at least one diode D1 connected in series, which cannot be controlled to turn on and off, and has unidirectional current carrying capacity and unidirectional voltage blocking capacity.

[0075] like Figure 9B As shown, the semi-controlled switch includes a thyristor T2 connected in series, which can only control the turn-on and cannot control the turn-off. It has unidirectional current carrying capacity and bidirectional voltage blocking capacity. Optionally, the semi-controlled switch is composed of thyristor T2 and diode D1 connected in series or in parallel.

[0076] like Figure 9C As shown, the unidirectional fully controlled switch includes an IGBT module Q1 connected in series. The IGBT module includes an IGBT and a diode connected in antiparallel with it. It can only control the turn-on and turn-off in one direction and has the ability to conduct current in both directions and block voltage in one direction.

[0077] like Figure 9D As shown, the unidirectional fully controlled switch includes an integrated gate commutator thyristor T3 connected in series, which can only control the opening and closing in one direction and has the capability of unidirectional current carrying and unidirectional voltage blocking. If it is a series-connected reverse-resistance type integrated gate commutator thyristor T3, it has the capability of unidirectional current carrying and bidirectional voltage blocking.

[0078] like Figure 9EAs shown, the unidirectional fully controlled switch includes an IGBT module Q1 and a diode D1 connected in series. It can only control the turn-on and turn-off in one direction, and has the ability to carry current in one direction and block voltage in both directions.

[0079] like Figure 9F As shown, the unidirectional fully controlled switch includes a series circuit consisting of a reverse-resistance integrated gate commutator thyristor T3 and a thyristor T2 connected in antiparallel. It has bidirectional control for turn-on and unidirectional control for turn-off, and has bidirectional current-carrying and bidirectional voltage-blocking capabilities.

[0080] like Figure 9G As shown, the bidirectional fully controlled switch includes a forward IGBT module Q1 and a reverse IGBT module Q1 connected in series. It can be bidirectionally controlled to turn on and off, and has bidirectional current carrying capacity and bidirectional voltage blocking capacity.

[0081] like Figure 9H As shown, the bidirectional fully controlled switch includes a series circuit after the reverse-resistance integrated gate commutator thyristor T3 is connected in anti-parallel. It can control the opening and closing in both directions and has bidirectional current carrying capacity and bidirectional voltage blocking capacity.

[0082] like Figure 9I As shown, the sub-module series switch includes a half-bridge sub-module connected in series. The half-bridge sub-module includes two IGBT modules Q1 and a capacitor C1. The connection point of the two IGBT modules Q1 serves as the positive terminal of the half-bridge sub-module, and the other end of one of the IGBT modules Q1 serves as the negative terminal of the half-bridge sub-module. The half-bridge sub-modules are connected in series and can only control the opening and closing in one direction. It has bidirectional current carrying capacity and unidirectional voltage blocking capacity.

[0083] like Figure 9J As shown, the sub-module series switch includes a full-bridge sub-module connected in series. The full-bridge sub-module includes four IGBT modules Q1 and a capacitor C1. The IGBT modules Q1 are connected in series in pairs and then connected in parallel, and are also connected in parallel with the capacitor C1. The connection points of the two IGBT modules Q1 connected in series in pairs serve as the positive and negative terminals of the full-bridge sub-module, respectively. The full-bridge sub-modules are connected in series, which can control the opening and closing in both directions, and has bidirectional current carrying capacity and bidirectional voltage blocking capacity.

[0084] like Figure 9K As shown, the sub-module series switch includes a series-connected quasi-full-bridge sub-module. The quasi-full-bridge sub-module includes two IGBT modules Q1, two diodes D1, and a capacitor C1. The IGBT modules Q1 and diodes D1 are connected in series and then in parallel, and are also connected in parallel with the capacitor C1. The connection point of the series connection between the IGBT modules Q1 and diodes D1 serves as the positive and negative terminals of the quasi-full-bridge sub-module, respectively. The quasi-full-bridge sub-modules are connected in series, enabling unidirectional control of turn-on and turn-off, and possessing bidirectional current-carrying capability and bidirectional voltage-blocking capability.

[0085] In some embodiments, the thyristor is configured with a corresponding trigger circuit and a buffer circuit; the IGBT is configured with a corresponding drive circuit and a buffer circuit; the IGCT or reverse-resistance IGCT is configured with a corresponding drive circuit and a buffer circuit; the buffer circuit consists of at least a capacitor, or a resistor and a capacitor in series circuit.

[0086] This application provides a controllable shutdown method for a hybrid grid commutator converter, executed by electronic equipment. The electronic equipment can be a control device, a server, or a terminal device. The control device is an independent physical controller. The server can be an independent physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing cloud computing services. The terminal device can be a smartphone, tablet, laptop, desktop computer, etc., but is not limited to these. The control device, server, and terminal device can be directly or indirectly connected via wired or wireless communication; this application does not impose specific limitations on these connections.

[0087] like Figure 10 As shown, this application also provides a controllable shutdown hybrid grid commutator control method, including: Step S101 and / or step S102, wherein, Step S101: When the AC side of the controllable shut-off hybrid grid phase converter is energized and the main circuit is not unlocked, select at least one phase of the upper bridge transfer circuit and at least one phase of the lower bridge transfer circuit. When at least one phase of the upper bridge transfer circuit is subjected to a positive voltage, control the upper bridge transfer circuit to be turned on or partially turned on. When at least one phase of the lower bridge transfer circuit is subjected to a positive voltage, control the lower bridge transfer circuit to be turned on or partially turned on.

[0088] In some embodiments, controlling the upper bridge transfer circuit to turn on or controlling the lower bridge transfer circuit to turn on is either immediate control or delayed control. The delayed control includes a delay when the hybrid grid phase-change converter is energized but the main circuit is not unlocked, and / or a delay when the upper bridge transfer circuit or the lower bridge transfer circuit is subjected to a positive voltage.

[0089] In some embodiments, after controlling the upper bridge transfer circuit to be turned on, the state of the upper bridge shutdown circuit is detected. If the state of the upper bridge shutdown circuit is normal, a normal energization signal for the upper bridge shutdown circuit is set to the valve control device. After controlling the lower bridge transfer circuit to be turned on, the state of the lower bridge shutdown circuit is detected. If the state of the lower bridge shutdown circuit is normal, a normal energization signal for the lower bridge shutdown circuit is set to the valve control device.

[0090] In some embodiments, when the valve control device receives a signal indicating that the upper bridge shutdown circuit or the lower bridge shutdown circuit is energized, it maintains a first time threshold, or maintains the valve assembly until it is unlocked, or maintains the valve assembly until it is de-energized.

[0091] In some embodiments, after the valve control device receives a normal energization signal for the upper bridge shutdown circuit, it will no longer control the upper bridge transfer circuit to conduct when at least one phase of the upper bridge transfer circuit is subjected to a positive voltage; after the valve control device receives a normal energization signal for the lower bridge shutdown circuit, it will no longer control the lower bridge transfer circuit to conduct when at least one phase of the lower bridge transfer circuit is subjected to a positive voltage.

[0092] Specifically, when the AC side of the controllable shut-off hybrid grid phase converter is energized and the main circuit is not unlocked, the upper bridge transfer circuit and the lower bridge transfer circuit of phase A are selected. When the upper bridge transfer circuit of phase A is subjected to positive voltage, the upper bridge transfer circuit is immediately or delayedly turned on. At this time, the impedance of the three-phase transfer circuit will be unbalanced, and the upper bridge shut-off circuit will be subjected to voltage and energized. The status of the upper bridge shut-off circuit is detected. If the status of the upper bridge shut-off circuit is normal, the upper bridge shut-off circuit energized normal signal is set to the valve control device (such as the valve base electronic unit VBE or the valve control unit VCU). The above-mentioned upper bridge shut-off circuit energized normal signal is maintained at the first time threshold as needed, such as 1 second, or until the valve group is unlocked, or until the valve group is de-energized. When the lower bridge transfer circuit of phase A is subjected to a positive voltage, the lower bridge transfer circuit is immediately or delayedly turned on. At this time, the lower bridge shutdown circuit will be subjected to voltage and energized. The status of the lower bridge shutdown circuit is detected. If the status of the lower bridge shutdown circuit is normal, the lower bridge shutdown circuit energized normal signal is set to the valve control device (such as the valve base electronic unit VBE or valve control unit VCU). The lower bridge shutdown circuit energized normal signal is maintained at a first time threshold, or maintained until the valve group is unlocked, or maintained until the valve group is de-energized as needed. Optionally, the first time threshold is 1 second.

[0093] In some embodiments, controlling the partial conduction of the upper bridge transfer circuit or the partial conduction of the lower bridge transfer circuit is either immediate control or delayed control conduction. The delayed control conduction includes a delay when the hybrid grid phase-change converter is energized but the main circuit is not unlocked, and / or a delay when the upper bridge transfer circuit or the lower bridge transfer circuit is subjected to a positive voltage.

[0094] In some embodiments, after partially turning on the upper bridge transfer circuit, the state of the upper bridge shutdown circuit is detected. If the state of the upper bridge shutdown circuit is normal, a normal energization signal for the upper bridge shutdown circuit is set to the valve control device. After partially turning on the lower bridge transfer circuit, the state of the lower bridge shutdown circuit is detected. If the state of the lower bridge shutdown circuit is normal, a normal energization signal for the lower bridge shutdown circuit is set to the valve control device.

[0095] In some embodiments, when the valve control device receives a signal indicating that the upper bridge shutdown circuit or the lower bridge shutdown circuit is energized, it maintains a first time threshold, or maintains the valve assembly until it is unlocked, or maintains the valve assembly until it is de-energized.

[0096] In some embodiments, after the valve control device receives a normal energization signal for the upper bridge shutdown circuit, it no longer controls the partial conduction of the upper bridge transfer circuit when at least one phase of the upper bridge transfer circuit is subjected to a positive voltage; after the valve control device receives a normal energization signal for the lower bridge shutdown circuit, it no longer controls the partial conduction of the lower bridge transfer circuit when at least one phase of the lower bridge transfer circuit is subjected to a positive voltage.

[0097] Specifically, when the AC side of the controllable shut-off hybrid grid phase-change converter is energized and the main circuit is not unlocked, the upper bridge transfer circuit and the lower bridge transfer circuit of phase A are selected. When the upper bridge transfer circuit of phase A is subjected to positive voltage, the third half-controlled valve part of the upper bridge transfer circuit is immediately or delayed to conduct. At this time, the impedance of the three-phase transfer circuit will be unbalanced, the upper bridge shut-off circuit will be subjected to voltage and energized, and the status of the upper bridge shut-off circuit is detected. If the status of the upper bridge shut-off circuit is normal, the upper bridge shut-off circuit energized normal signal is set to the valve control device (such as the valve base electronic unit VBE or the valve control unit VCU). The above-mentioned upper bridge shut-off circuit energized normal signal is maintained at the first time threshold as needed, such as 1 second, or until the valve group is unlocked, or until the valve group is de-energized. When the lower bridge transfer circuit of phase A is subjected to a positive voltage, the third semi-controlled valve part of the lower bridge transfer circuit is immediately or delayed to conduct. At this time, the lower bridge shutdown circuit will be subjected to voltage and energized. The status of the lower bridge shutdown circuit is detected. If the status of the lower bridge shutdown circuit is normal, the lower bridge shutdown circuit energized normal signal is set to the valve control device (such as the valve base electronic unit VBE or valve control unit VCU). The lower bridge shutdown circuit energized normal signal is maintained at a first time threshold, or maintained until the valve group is unlocked, or maintained until the valve group is de-energized as needed. Optionally, the first time threshold is 1 second.

[0098] Step S102: When the controllable shutdown hybrid grid phase converter is unlocked and running normally, if the current in the main circuit is lower than the preset threshold, the auxiliary circuit connected in parallel with the main circuit is controlled to conduct or present a negative voltage, and the main circuit is controlled to turn off or the negative voltage is used to turn off the main circuit.

[0099] In some embodiments, when the controllable shut-off hybrid grid commutator is unlocked and operating normally, taking the upper arm of phase A as an example, before controlling the main circuit of the upper arm of phase A to shut down, when the current of the main circuit of the upper arm of phase A is zero or close to zero, if the main circuit has a full control valve, the auxiliary circuit of the upper arm of phase A connected in parallel with the main circuit of the upper arm of phase A is controlled to conduct. After a delay of a second time threshold, the main circuit of the upper arm of phase A is controlled to shut down. If the main circuit does not have a full control valve, the auxiliary circuit of the upper arm of phase A connected in parallel with the main circuit of the upper arm of phase A is controlled to present a negative voltage, so that the main circuit of the upper arm of phase A is shut down. The above-mentioned "close to zero" is determined based on the current of the main circuit of the upper arm of phase A being less than a first current threshold. Optionally, the first current threshold ranges from -100A to 100A; or it is determined based on the converter triggering time and commutation time predicting the end of the commutation process.

[0100] When the current in the main circuit is lower than a preset threshold, the auxiliary circuit connected in parallel with the main circuit is turned on, and after a second time threshold, the main circuit is turned off; the second time threshold ranges from 0 to 1 ms.

[0101] like Figure 11 As shown, a controllable shutdown hybrid power grid phase converter control method is applicable to... Figure 1 and Figure 3 The structure also includes: Steps S201, S202, and S203, wherein, Step S201: After obtaining the operating parameter information of the controllable shutdown hybrid grid phase converter, inverter state control information is generated based on the parameter information, and the main circuit is controlled to operate in inverter state based on the inverter state control information.

[0102] In some embodiments, the electronic device monitors the operating status of the controllable shutdown hybrid grid-commutated converter in real time and obtains operating parameter information of the controllable shutdown hybrid grid-commutated converter, such as AC voltage and DC current. When the electronic device obtains the operating status of the controllable shutdown hybrid grid-commutated converter, the electronic device generates inverter status control information, such as trigger pulses. The controllable shutdown hybrid grid-commutated converter operates in inverter state according to the six-pulse inverter working mode based on the inverter status control information.

[0103] When the controllable shut-off hybrid grid phase-change converter is operating in inverter mode, the upper and lower bridge arm circuits of different phases of the main circuit of the controllable shut-off hybrid grid phase-change converter are turned on, that is, the first full control valve, the first half control valve and / or the second half control valve in the upper and lower bridge arm circuits of different phases are turned on simultaneously.

[0104] Step S202: Upon obtaining commutation fault information, generate a circuit turn-on command and a first circuit turn-off command, and control the transfer circuit and turn-off circuit in the auxiliary circuit corresponding to the commutation bridge arm to turn on based on the circuit turn-on command; control the first full control valve contained in the commutation bridge arm to turn off based on the first circuit turn-off command.

[0105] In some embodiments, the commutation arm is an upper arm circuit and / or a lower arm circuit.

[0106] When the electronic device receives commutation fault information of the controllable shutdown hybrid grid commutator, and this commutation fault information is the fault information causing the natural commutation failure of the commutation arm of the main circuit, the electronic device generates a circuit turn-on command. The controllable shutdown hybrid grid commutator responds to the circuit turn-on command, causing the transfer circuit and the turn-off circuit in the auxiliary circuit corresponding to the commutation arm of the controllable shutdown hybrid grid commutator to turn on. For example, when it is predicted that a natural commutation failure will occur in the upper arm circuit of phase A, the electronic device generates a circuit turn-on command, and the controllable shutdown hybrid grid commutator responds to the circuit turn-on command. The command enables the upper bridge transfer circuit and upper bridge shutdown circuit in the auxiliary circuit corresponding to the upper bridge arm circuit of phase A to be turned on; at the same time, the electronic equipment generates a first circuit shutdown command, and the controllable shutdown hybrid grid commutation converter responds to the first circuit shutdown command to shut off the first full control valve of the commutation bridge arm, thereby transferring the current of the commutation bridge arm to the upper bridge transfer circuit and upper bridge shutdown circuit in the corresponding auxiliary circuit. For example, when it is predicted that the upper bridge arm circuit of phase A will experience natural commutation failure, the electronic equipment generates a first circuit shutdown command, and the grid commutation converter responds to the first circuit shutdown command to shut off the first full control valve of the upper bridge arm circuit of phase A.

[0107] Step S203: When the first half-control valve of the commutation bridge arm of the main circuit is restored to shut off, a second circuit shutdown command is generated to control the shutdown circuit corresponding to the commutation bridge arm to shut off.

[0108] In some embodiments, when the electronic device detects that the first half-controlled valve of the commutation bridge arm of the main circuit has resumed shutdown, a second circuit shutdown command is generated. The controllable shutdown hybrid grid commutation converter responds to the second circuit shutdown command and controls the shutdown circuit corresponding to the commutation bridge arm to shut down, so that the current is transferred from the phase power of the commutation bridge arm to the phase power to be commutated, effectively suppressing the occurrence of commutation failure. For example, when the electronic device detects that the first half-controlled valve of the upper bridge arm circuit of phase A of the main circuit has resumed shutdown, a second circuit shutdown command is generated. The controllable shutdown hybrid grid commutation converter responds to the second circuit shutdown command and controls the upper bridge shutdown circuit corresponding to the upper bridge arm circuit of phase A to shut down, so that the current is transferred from the upper bridge arm of phase A to the upper bridge arm of phase B, thereby suppressing the occurrence of commutation failure.

[0109] In some embodiments, taking the A-phase upper bridge arm circuit of the main circuit as an example, when the A-phase upper bridge arm circuit commutates to the B-phase upper bridge arm circuit, if a fault is detected that will cause the first half-controlled valve V42 and the second half-controlled valve V43 of the A-phase upper bridge arm circuit of the main circuit to fail to commutate naturally, the third half-controlled valve or the first uncontrolled valve V44 of the A-phase upper bridge transfer circuit of the auxiliary circuit and the second fully controlled valve V71 of the upper bridge shutdown circuit are turned on; the first fully controlled valve V41 of the A-phase upper bridge arm circuit is turned off, so that the current of the A-phase upper bridge arm circuit is transferred to the A-phase upper bridge transfer circuit and the upper bridge shutdown circuit of the auxiliary circuit; after the first half-controlled valve V42 of the A-phase upper bridge arm circuit is turned off again, the second fully controlled valve V71 of the upper bridge shutdown circuit is turned off to provide additional commutation voltage, thereby realizing the transfer of current from the A-phase upper bridge arm circuit to the B-phase upper bridge arm circuit.

[0110] In some embodiments, taking the A-phase lower bridge arm circuit of the main circuit as an example, when the A-phase lower bridge arm circuit commutates to the B-phase lower bridge arm circuit, if a fault is detected that will cause the first half-controlled valve V12 and the second half-controlled valve V13 of the A-phase lower bridge arm circuit of the main circuit to fail to commutate naturally, the third half-controlled valve or the first uncontrolled valve V14 of the A-phase lower bridge transfer circuit of the auxiliary circuit and the second fully controlled valve V72 of the lower bridge shutdown circuit are turned on; the first fully controlled valve V11 of the A-phase lower bridge arm circuit is turned off, so that the current of the A-phase lower bridge arm circuit is transferred to the A-phase lower bridge transfer circuit and the lower bridge shutdown circuit of the auxiliary circuit; after the first half-controlled valve V12 of the A-phase lower bridge arm circuit is turned off again, the second fully controlled valve V72 of the lower bridge shutdown circuit is turned off to provide additional commutation voltage, thereby realizing the transfer of current from the A-phase lower bridge arm circuit to the B-phase lower bridge arm circuit.

[0111] In some embodiments, the first semi-controlled valve in the commutation bridge arm of the main circuit is restored to shutdown by determining the reverse recovery time of the first semi-controlled valve. The reverse recovery time is greater than or equal to the reverse recovery time of the thyristor included in the first semi-controlled valve. The typical reverse recovery time of the thyristor is 200 μs to 800 μs, and the typical reverse recovery time of the first semi-controlled valve is 200 μs to 1500 μs.

[0112] like Figure 12 As shown, a controllable shutdown hybrid power grid phase converter control method is applicable to... Figure 2 and Figure 4 The structure also includes: Steps S301, S302, and S303, wherein, Step S301: After obtaining the operating parameter information of the controllable shutdown hybrid grid phase converter, inverter state control information is generated based on the parameter information, and the main circuit is controlled to operate in inverter state based on the inverter state control information.

[0113] In some embodiments, the electronic device monitors the operating status of the controllable shutdown hybrid grid-commutated converter in real time and obtains operating parameter information of the controllable shutdown hybrid grid-commutated converter, such as AC voltage and DC current. When the electronic device obtains the operating status of the controllable shutdown hybrid grid-commutated converter, the electronic device generates inverter status control information, such as trigger pulses. The controllable shutdown hybrid grid-commutated converter operates in inverter state according to the six-pulse inverter working mode based on the inverter status control information.

[0114] When the controllable shut-off hybrid grid phase-change converter is operating in inverter mode, the upper and lower bridge arm circuits of different phases of the main circuit of the controllable shut-off hybrid grid phase-change converter are turned on, that is, the first full control valve, the first half control valve and / or the second half control valve in the upper and lower bridge arm circuits of different phases are turned on simultaneously.

[0115] In step S302, upon obtaining commutation fault information, a circuit turn-on command and a first circuit turn-off command are generated, and based on the circuit turn-on command, the transfer circuit in the auxiliary circuit corresponding to the commutation bridge arm is controlled to turn on and the turn-off circuit presents a negative voltage.

[0116] In some embodiments, the commutation bridge arm is an upper bridge arm circuit and / or a lower bridge arm circuit.

[0117] When the electronic device receives commutation fault information of the controllable shutdown hybrid grid commutator, and the commutation fault information is fault information that causes the natural commutation failure of the commutation bridge arm of the main circuit, the electronic device generates a circuit turn-on command. The controllable shutdown hybrid grid commutator responds to the circuit turn-on command, causing the transfer circuit and the turn-off circuit in the auxiliary circuit corresponding to the commutation bridge arm of the controllable shutdown hybrid grid commutator to present a negative voltage. For example, when it is predicted that the upper bridge arm circuit of phase A will experience a natural commutation failure, the electronic device generates a circuit turn-on command. The controllable shutdown hybrid grid commutator responds to the circuit turn-on command, causing the upper bridge transfer circuit and the upper bridge turn-off circuit in the auxiliary circuit corresponding to the upper bridge arm circuit of phase A to present a negative voltage, thereby transferring the current of the commutation bridge arm to the upper bridge transfer circuit and the upper bridge turn-off circuit in the corresponding auxiliary circuit.

[0118] In step S303, when the first half-control valve of the commutation bridge arm of the main circuit is restored to shut off, a second circuit shutdown command is generated to control the shutdown circuit corresponding to the commutation bridge arm to shut off.

[0119] In some embodiments, when the electronic device detects that the first half-controlled valve of the commutation bridge arm of the main circuit has resumed shutdown, a second circuit shutdown command is generated. The controllable shutdown hybrid grid commutation converter responds to the second circuit shutdown command and controls the shutdown circuit corresponding to the commutation bridge arm to shut down, so that the current is transferred from the phase power of the commutation bridge arm to the phase power to be commutated, effectively suppressing the occurrence of commutation failure. For example, when the electronic device detects that the first half-controlled valve of the upper bridge arm circuit of phase A of the main circuit has resumed shutdown, a second circuit shutdown command is generated. The controllable shutdown hybrid grid commutation converter responds to the second circuit shutdown command and controls the upper bridge shutdown circuit corresponding to the upper bridge arm circuit of phase A to shut down, so that the current is transferred from the upper bridge arm of phase A to the upper bridge arm of phase B, thereby suppressing the occurrence of commutation failure.

[0120] In some embodiments, reference Figure 6 Taking the A-phase upper bridge arm circuit of the main circuit as an example, when the A-phase upper bridge arm circuit switches to the B-phase upper bridge arm circuit, if a fault is detected that will cause the first half-control valve V42 and the second half-control valve V43 of the A-phase upper bridge arm circuit of the main circuit to fail to switch naturally, the third half-control valve of the A-phase upper bridge transfer circuit of the auxiliary circuit will be turned on and the second full-control valve V71 of the upper bridge turn-off circuit will be under negative pressure, so that the current of the A-phase upper bridge arm circuit will be transferred to the A-phase upper bridge transfer circuit and the upper bridge turn-off circuit of the auxiliary circuit. After the first half-control valve V42 of the A-phase upper bridge arm circuit is turned off again, the second full-control valve V71 of the upper bridge turn-off circuit will be turned off, providing additional commutation voltage, thus realizing the transfer of current from the A-phase upper bridge arm circuit to the B-phase upper bridge arm circuit.

[0121] In some embodiments, taking the A-phase lower bridge arm circuit of the main circuit as an example, when the A-phase lower bridge arm circuit commutates to the B-phase lower bridge arm circuit, if a fault is detected that will cause the first half-control valve V12 and the second half-control valve V13 of the A-phase lower bridge arm circuit of the main circuit to fail to commutate naturally, the third half-control valve V14 of the A-phase lower bridge transfer circuit of the auxiliary circuit will be turned on and the second fully control valve V72 of the lower bridge turn-off circuit will be under negative pressure, so that the current of the A-phase lower bridge arm circuit will be transferred to the A-phase lower bridge transfer circuit and the lower bridge turn-off circuit of the auxiliary circuit. After the first half-control valve V12 of the A-phase lower bridge arm circuit is turned off again, the second fully control valve V72 of the lower bridge turn-off circuit will be turned off to provide additional commutation voltage, thereby realizing the transfer of current from the A-phase lower bridge arm circuit to the B-phase lower bridge arm circuit.

[0122] In some embodiments, when the electronic device obtains auxiliary circuit fault information, a switch separation command is generated, and the isolation switch and / or knife switch corresponding to the auxiliary circuit are controlled to separate based on the switch separation command, thereby reducing the occurrence of main circuit damage or inoperability caused by auxiliary circuit faults.

[0123] In some embodiments, when a fourth semi-control valve is connected in parallel across the first full control valve and the electronic device obtains overpressure or fault information of the first full control valve, a first valve opening command is generated, and the fourth semi-control valve is controlled to open based on the first valve opening command, thereby protecting the first full control valve.

[0124] In some embodiments, a second uncontrolled valve is connected in series with a first fully controlled valve, and a fourth semi-controlled valve is connected in parallel at both ends of the series connection between the first fully controlled valve and the second uncontrolled valve. When the electronic device obtains overpressure or fault information of the first fully controlled valve, it generates a second valve opening command and controls the fourth semi-controlled valve to open based on the second valve opening command, thereby protecting the first fully controlled valve.

[0125] In some embodiments, commutation fault information includes fault information that causes the commutation bridge arm of the main circuit to fail to commutate naturally. The aforementioned commutation fault information includes AC system faults or DC system faults that controllably disconnect the hybrid grid commutation converter connection. AC system faults can be determined based on an increase in the zero-sequence component of AC voltage, a sudden change in AC voltage, a drop in AC voltage amplitude, an increase in AC voltage harmonics, and an increase in DC current. DC system faults can be determined based on a drop in DC voltage and an increase in DC current, but are not limited to these criteria.

[0126] In some embodiments, the aforementioned natural commutation failure refers to commutation failure that occurs when commutation is performed solely by the commutation voltage provided by the AC system. Whether a natural commutation failure occurs can be determined based on the shut-off times of the second and third half-controlled valves, the AC current and AC voltage on the grid side or valve side. If the second and third half-controlled valves of the commutation bridge arm have not shut off by the time they begin to bear positive pressure under normal AC voltage, it is judged as a natural commutation failure, but this is not a limitation.

[0127] like Figure 13 The diagram illustrates the effect of a method for controlling the shutdown of a hybrid grid phase-change converter when it is energized and the main circuit is not unlocked. Here, uA, uB, and uC represent AC side voltages; u14 and u44 represent the voltages of the A-phase upper bridge transfer circuit and the A-phase lower bridge transfer circuit, respectively; and u71 and u72 represent the voltages of the upper bridge shutdown circuit and the lower bridge shutdown circuit, respectively. When the controllable shutdown hybrid grid phase-change converter is energized, a certain delay is performed. After the delay is satisfied, when the A-phase upper bridge transfer circuit experiences a positive voltage, the upper bridge transfer circuit is turned on. At this time, the upper bridge shutdown circuit will experience voltage and be energized. Similarly, when the A-phase lower bridge transfer circuit experiences a positive voltage, the lower bridge transfer circuit is turned on. At this time, the lower bridge shutdown circuit will experience voltage and be energized.

[0128] like Figure 14 As shown, it illustrates Figure 7The diagram shown depicts a simulation of a controllable shut-off hybrid grid-connected converter with the main circuit not unlocked. In this simulation, u11 represents the voltage of the first fully controlled valve of the lower arm of phase A, u12 represents the voltage of the first partially controlled valve of the lower arm of phase A, u72 represents the voltage of the lower bridge shut-off circuit, u14 represents the voltage of the lower arm transfer circuit of phase A, FP_V11 represents the trigger pulse of the first fully controlled valve of the lower arm of phase A, FP_V12 represents the trigger pulse of the first partially controlled valve of the lower arm of phase A, FP_V72 represents the trigger pulse of the lower bridge shut-off circuit, and FP_V14 represents the trigger pulse of the lower arm transfer circuit of phase A. When the trigger pulse of the lower arm transfer circuit of phase A is high, the lower arm transfer circuit of phase A is turned on, and a positive voltage appears across the lower bridge shut-off circuit.

[0129] like Figure 15 As shown, the controllable shutdown hybrid grid phase-change converter control device 20 may specifically include: a first control module 201 and / or a second control module 202, wherein, The first control module 201 is used to select at least one phase of the upper bridge transfer circuit and at least one phase of the lower bridge transfer circuit when the AC side of the controllable shut-off hybrid grid phase-change converter is energized but not unlocked. When the upper bridge transfer circuit of at least one phase is subjected to a positive voltage, the upper bridge transfer circuit is controlled to be turned on or partially turned on. When the lower bridge transfer circuit of at least one phase is subjected to a positive voltage, the lower bridge transfer circuit is controlled to be turned on or partially turned on. The second control module 202 is used to control the auxiliary circuit connected in parallel with the main circuit to conduct or present a negative voltage when the current of the main circuit is lower than a preset threshold, and to control the main circuit to turn off or use the negative voltage to turn off the main circuit when the controllable shutdown hybrid grid phase converter is unlocked and running normally.

[0130] In some embodiments, the first control module 201 may include logic circuits, or may be implemented by a central processing unit, microprocessor, digital signal processor or field programmable gate array included in the device; The second control module 202 may include logic circuits or be implemented by a central processing unit, microprocessor, digital signal processor or field programmable gate array included in the device.

[0131] A controllable shutdown hybrid grid phase-commutator system 30, such as Figure 16 As shown. Specifically, it may include: a controllable shutdown hybrid grid phase-commutator converter 301 and a controllable shutdown hybrid grid phase-commutator control device 20.

[0132] The controllable shutdown hybrid power grid phase converter control method, device and system provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A controllable shutdown method for a hybrid grid phase-commutator, characterized in that, include: When the AC side of the controllable shut-off hybrid grid phase converter is energized and the main circuit is not unlocked, at least one phase of the upper bridge transfer circuit and at least one phase of the lower bridge transfer circuit are selected. When the upper bridge transfer circuit of at least one phase is subjected to a positive voltage, the upper bridge transfer circuit is controlled to be turned on or partially turned on. When the lower bridge transfer circuit of at least one phase is subjected to a positive voltage, the lower bridge transfer circuit is controlled to be turned on or partially turned on. and When the controllable shutdown hybrid grid phase converter is unlocked and operating normally, if the current in the main circuit is lower than a preset threshold, the auxiliary circuit connected in parallel with the main circuit is controlled to conduct or present a negative voltage, thereby controlling the main circuit to shut down or using the negative voltage to shut down the main circuit.

2. The controllable shutdown hybrid grid phase-commutator control method according to claim 1, characterized in that, The control of the upper bridge transfer circuit to be turned on or partially turned on, or the control of the lower bridge transfer circuit to be turned on or partially turned on, is an immediate control or a delayed control; the delayed control includes the delay when the controllable shutdown hybrid grid phase converter is energized but the main circuit is not unlocked, and / or the delay after the upper bridge transfer circuit or the lower bridge transfer circuit is subjected to a positive voltage.

3. The controllable shutdown hybrid grid phase-commutator control method according to claim 1, characterized in that, The control method further includes: After controlling the upper bridge transfer circuit to be turned on or partially turned on, the operating status of the upper bridge shutdown circuit is detected. If the upper bridge shutdown circuit is in normal condition, a normal power-on signal for the upper bridge shutdown circuit is generated and set, and the signal is sent to the valve control device. After controlling the lower bridge transfer circuit to be turned on or partially turned on, the operating status of the lower bridge shutdown circuit is detected. If the lower bridge shutdown circuit is in normal condition, a signal indicating that the lower bridge shutdown circuit is energized and set is generated and sent to the valve control device.

4. The controllable shutdown hybrid grid phase-commutator control method according to claim 3, characterized in that, The control method further includes: When the valve control device receives a signal indicating that the upper bridge shutdown circuit or the lower bridge shutdown circuit is energized, it maintains the first time threshold, or maintains the signal until the valve group is unlocked, or maintains the signal until the valve group is de-energized.

5. The controllable shutdown hybrid grid phase-commutator control method according to claim 3, characterized in that, The control method further includes: After the valve control device receives the normal energization signal of the upper bridge shutdown circuit, when at least one phase of the upper bridge transfer circuit is subjected to a positive voltage, it stops triggering the upper bridge transfer circuit to conduct or partially conduct. After the valve control device receives the normal energization signal of the lower bridge shutdown circuit, it stops triggering the lower bridge transfer circuit to conduct or partially conduct when at least one phase of the lower bridge transfer circuit is subjected to a positive voltage.

6. The controllable shutdown hybrid grid phase-commutator control method according to claim 1, characterized in that, The method for determining that the main circuit current is lower than the preset threshold includes at least one of the following: The current in the main circuit is determined to be less than a first current threshold, wherein the value of the first current threshold is in the range of -100A to 100A. Based on the triggering time and commutation time of the controllable shutdown hybrid power grid commutator, the prediction is made after the commutation process is completed.

7. The controllable shutdown hybrid grid phase-commutator control method according to claim 1, characterized in that, When the current in the main circuit is lower than a preset threshold, the auxiliary circuit connected in parallel with the main circuit is turned on, and after a second time threshold, the main circuit is turned off; the second time threshold ranges from 0 to 1 ms.

8. The controllable shutdown hybrid grid phase-commutator control method according to claim 1, characterized in that, The control method further includes: Obtain the operating parameter information of the controllable shutdown hybrid grid phase converter; Inverter state control information is generated based on the aforementioned operating parameter information; Based on the inverter state control information, the main circuit is controlled to operate in inverter state.

9. The controllable shutdown hybrid grid phase-commutator control method according to claim 3, characterized in that, The control method further includes: Upon obtaining the commutation fault information of the controllable shutdown hybrid power grid commutator, a circuit turn-on command and a first circuit turn-off command are generated based on the commutation fault information. Based on the circuit turn-on command, the transfer circuit and / or turn-off circuit in the auxiliary circuit corresponding to the commutation bridge arm are turned on; based on the first circuit turn-off command, the first full control valve included in the commutation bridge arm is turned off or the second full control valve is at negative pressure; wherein, the commutation bridge arm is an upper bridge arm circuit or a lower bridge arm circuit. When the first half-control valve of the commutation bridge arm in the main circuit is restored to shutdown, a second circuit shutdown command is generated to control the shutdown circuit in the auxiliary circuit corresponding to the commutation bridge arm to shut down.

10. The controllable shutdown hybrid grid phase-commutator control method according to claim 9, characterized in that, When the commutation bridge arm is the upper bridge arm circuit, the transfer circuit in the auxiliary circuit corresponding to the commutation bridge arm is the upper bridge transfer circuit that is in phase with the upper bridge arm circuit, and the shutdown circuit in the auxiliary circuit corresponding to the commutation bridge arm is the upper bridge shutdown circuit. When the commutation bridge arm is the lower bridge arm circuit, the transfer circuit in the auxiliary circuit corresponding to the commutation bridge arm is the lower bridge transfer circuit that is in phase with the lower bridge arm circuit, and the shutdown circuit in the auxiliary circuit corresponding to the commutation bridge arm is the lower bridge shutdown circuit.

11. The controllable shutdown hybrid grid phase-commutator control method according to claim 9, characterized in that, The control method further includes: It is determined whether the first semi-controlled valve included in the commutation bridge arm of the main circuit has resumed shutdown. The shutdown of the first semi-controlled valve is determined based on the reverse recovery time of the first semi-controlled valve, which is greater than or equal to the reverse recovery time of the thyristor included in the first semi-controlled valve.

12. The controllable shutdown hybrid grid phase-commutator control method according to claim 9, characterized in that, The control method further includes: If fault information of the auxiliary circuit is obtained, a switch-off command is generated based on the fault information of the auxiliary circuit. Based on the switch separation command, the corresponding isolating switch and / or knife switch of the auxiliary circuit are controlled to separate.

13. The controllable shutdown hybrid grid phase-commutator control method according to claim 9, characterized in that, The control method further includes: When a fourth semi-control valve is connected in parallel across the first fully control valve, and overpressure or fault information of the first fully control valve is obtained, a first valve opening command is generated, and the fourth semi-control valve is controlled to open based on the first valve opening command; or; When a second uncontrolled valve is connected in series with the first fully controlled valve, and a fourth semi-controlled valve is connected in parallel at both ends of the series connection between the first fully controlled valve and the second uncontrolled valve, and when overpressure information or fault information of the first fully controlled valve is obtained, a second valve opening command is generated, and the fourth semi-controlled valve is controlled to open based on the second valve opening command.

14. A controllable shutdown hybrid grid commutator control device, employing the controllable shutdown hybrid grid commutator control method as described in any one of claims 1 to 13, characterized in that, include: The first control module is used to select at least one phase of the upper bridge transfer circuit and at least one phase of the lower bridge transfer circuit when the AC side of the controllable shut-off hybrid grid phase-change converter is energized and the main circuit is not unlocked. When the upper bridge transfer circuit of at least one phase is subjected to a positive voltage, the module controls the upper bridge transfer circuit to be turned on or partially turned on. When the lower bridge transfer circuit of at least one phase is subjected to a positive voltage, the module controls the lower bridge transfer circuit to be turned on or partially turned on. and The second control module is used to control the auxiliary circuit connected in parallel with the main circuit to conduct or present a negative voltage when the controllable shutdown hybrid grid phase converter is unlocked and operating normally, and when the current of the main circuit is lower than a preset threshold, thereby controlling the main circuit to shut down or using the negative voltage to shut down the main circuit.

15. A controllable shutdown hybrid grid phase-commutator system, characterized in that, Includes the controllable shutdown hybrid grid phase-commutator control device as described in claim 14.

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