Bidirectional DC / DC Converter Fault Ride-Through Method, Device, Electronic Equipment and Storage Medium

Abstract

The present application provides a novel fault ride-through method, device, electronic device and storage medium for a bidirectional DC / DC converter, which relates to the field of power equipment maintenance, and includes: when it is determined that an external fault occurs in the converter based on the arm current of the converter, controlling the converter to perform a short-time locking action; when it is detected that the external fault is eliminated, controlling the converter to be connected to the grid and restore the voltage; wherein, when restoring the voltage, based on the voltage drops borne by each sub-module in the converter, unlocking each sub-module in sequence to achieve fault ride-through. The present application enables the novel bidirectional DC / DC converter to complete fault ride-through.

Description

Technical Field

[0001] This application relates to the field of power equipment maintenance, and specifically to a novel two-way DC / DC converter fault ride-through method and device. Background Art

[0002] In order to meet the transmission requirements of high voltage and high power in transmission lines, the prior art mostly uses an input series-output parallel (abbreviated as ISOP type) topology to construct a high voltage-low voltage DC converter. This topology consists of multiple isolated power modules. The modules on the input side are connected in series to ensure that they can withstand medium and high voltages, and the output side is connected in parallel to the low voltage bus to output a large current. The topology of the ISOP type is shown in Figure 1 as shown.

[0003] Among them, the isolated dual active bridge converter (abbreviated as isolated DAB converter) is a typical one based on the ISOP type topology, and it is widely used because of its many excellent characteristics. The topology of the isolated DAB converter is relatively simple, consisting of a high-frequency inverter on the input side, a high-frequency transformer in the middle, and a high-frequency rectifier on the output side. The structure is shown in Figure 2 as shown. Multiple isolated DAB converters can be combined in series and parallel to obtain an ISOP-DAB DC transformer, and the structure is shown in Figure 3 as shown. Figure 3 All DAB modules in are expected to have exactly the same parameters. However, limited by the actual manufacturing process, each module contains many components, and there will inevitably be differences in parameters.

[0004] Figure 4 Shows a novel two-way DC / DC converter, which can better solve the above problems. For this novel two-way DC / DC converter, there is currently no corresponding fault ride-through method. Therefore, when an external fault occurs in this novel two-way DC / DC converter or some of its internal IGBTs (Insulated Gate Bipolar Transistors) fail, the converter will stop running completely. Especially for large DC / DC converters, there are several groups of two-way DC / DC converters working in parallel. If a fault occurs in one group of converters, it will cause the entire group of converters to exit, and post-fault troubleshooting and post-fault recovery will be carried out, which will relatively affect production operation. Summary of the Invention

[0005] Aiming at the problems in the prior art, this application provides a novel two-way DC / DC converter fault ride-through method and device, which can enable the novel two-way DC / DC converter to complete fault ride-through.

[0006] To solve the above technical problems, this application provides the following technical solutions:

[0007] In a first aspect, the present application provides a novel fault ride-through method for a bidirectional DC / DC converter, including:

[0008] When it is determined based on the arm current of the converter that an external fault has occurred in the converter, controlling the converter to perform a short-term locking action;

[0009] When it is detected that the external fault has been eliminated, controlling the converter to be connected to the grid and restoring the voltage; wherein, when restoring the voltage, based on the voltage drops borne by each sub-module in the converter, unlocking each sub-module in sequence to achieve fault ride-through.

[0010] Further, the converter includes a power transfer side; the step of detecting the elimination of the external fault includes:

[0011] Judging whether there is an abnormal situation in the voltage of the power transfer side; wherein, the abnormal situation includes: abnormal three-phase voltage asymmetry, low voltage abnormality, and voltage over-limit abnormality;

[0012] If there is no abnormal situation, judging whether the DC circuit breaker corresponding to the converter is in the closed position and judging whether the control board of the sub-module of the converter is powered normally;

[0013] If it is determined that the DC circuit breaker corresponding to the converter is in the closed position and it is determined that the control board of the sub-module of the converter is powered normally, it is determined that the external fault has been eliminated.

[0014] Further, before controlling the converter to be connected to the grid and restoring the voltage, it further includes:

[0015] Controlling each sub-module to perform a chopping operation so that the high-frequency transformer corresponding to the converter conducts alternating current.

[0016] Further, the unlocking each sub-module in sequence based on the voltage drops borne by each sub-module in the converter to achieve fault ride-through includes:

[0017] Determining the unlocking order of each sub-module based on the voltage drops borne by each sub-module in the converter;

[0018] Unlocking each sub-module according to the order to achieve fault ride-through.

[0019] Further, the converter includes a support voltage side, and the method further includes:

[0020] Performing a temporary voltage setting for the sub-modules on the support voltage side;

[0021] Performing a trial power transmission for the converter based on the result of the temporary voltage setting to prevent a failure in the trial power transmission from causing a fault.

[0022] In a second aspect, the present application provides a novel bidirectional DC / DC converter fault ride-through device, including:

[0023] A locking action unit, configured to control the converter to perform a short-time locking action when it is determined based on the arm current of the converter that an external fault has occurred in the converter;

[0024] A grid connection restoration unit, configured to control the converter to perform grid connection and voltage restoration when it is detected that the external fault has been lifted; wherein, when performing voltage restoration, based on the voltage drops borne by each sub-module in the converter, each sub-module is unlocked in sequence to achieve fault ride-through.

[0025] Further, the converter includes a power transfer side; the grid connection restoration unit includes:

[0026] An abnormality judgment module, configured to judge whether there is an abnormal condition in the voltage of the power transfer side; wherein, the abnormal condition includes: three-phase voltage asymmetry abnormality, low voltage abnormality, and voltage over-limit abnormality;

[0027] A breaker state judgment module, configured to judge whether the DC breaker corresponding to the converter is in the closed position;

[0028] A control board state judgment module, configured to judge whether the sub-module control board of the converter is powered normally;

[0029] A fault clearance determination module, configured to determine that the external fault has been lifted.

[0030] Further, the converter fault ride-through device further includes:

[0031] A chopping execution unit, configured to control each sub-module to perform a chopping operation so that the high-frequency transformer corresponding to the converter conducts alternating current.

[0032] Further, the module unlocking unit includes:

[0033] An unlocking sequence determination module, configured to determine the unlocking sequence of each sub-module based on the voltage drops borne by each sub-module in the converter;

[0034] An unlocking execution module, configured to unlock each sub-module in accordance with the sequence to achieve fault ride-through.

[0035] Further, the converter includes a support voltage side, and the device further includes:

[0036] A voltage setting unit, configured to perform temporary voltage setting for the sub-modules on the support voltage side;

[0037] The power transmission unit is used to test power transmission to the converter based on the result of the temporary voltage setting to prevent failure of the test power transmission from causing faults.

[0038] In a third aspect, the present application provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the novel bidirectional DC / DC converter fault ride-through method when executing the program.

[0039] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the novel bidirectional DC / DC converter fault ride-through method.

[0040] In response to the problems in the prior art, the novel bidirectional DC / DC converter fault ride-through method and device provided in the present application can detect the removal of external faults, and when restoring the voltage, can unlock each sub-module in sequence based on the voltage drop borne by each sub-module in the converter, so that the sub-module borne by the lower voltage drop is unlocked first, and the sub-module borne by the higher voltage drop is unlocked later, thereby allowing the sub-module borne by the lower voltage drop to perform voltage recovery first, and the sub-module borne by the higher voltage drop to perform voltage recovery later, thereby ensuring the operating safety of the converter equipment during the voltage recovery process, realizing fault ride-through of the novel bidirectional DC / DC converter, and enabling it to resume operation as soon as possible after the fault. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0042] Figure 1 It is a schematic diagram of the ISOP structure in the prior art;

[0043] Figure 2 It is a structural schematic diagram of an isolated DAB converter in the prior art;

[0044] Figure 3 It is a structural schematic diagram of an ISOP-DAB DC transformer in the prior art;

[0045] Figure 4 It is a schematic diagram of the topology of a novel bidirectional DC / DC converter;

[0046] Figure 5 This is one of the flow charts of the novel bidirectional DC / DC converter fault ride-through method in the embodiment of the present application;

[0047] Figure 6 This is a flow chart for detecting the external fault removal in an embodiment of the present application;

[0048] Figure 7 This is a flow chart of sequentially unlocking each submodule in an embodiment of the present application;

[0049] Figure 8 This is the second flow chart of the novel bidirectional DC / DC converter fault ride-through method in the embodiment of the present application;

[0050] Figure 9 This is one of the structural diagrams of the novel bidirectional DC / DC converter fault ride-through device in the embodiment of the present application;

[0051] Figure 10 This is a structural diagram of a grid-connected recovery unit in an embodiment of the present application;

[0052] Figure 11 This is a structural diagram of a module unlocking unit in an embodiment of the present application;

[0053] Figure 12 This is the second structural diagram of the novel bidirectional DC / DC converter fault ride-through device in the embodiment of the present application;

[0054] Figure 13 A schematic diagram of the structure of an electronic device in an embodiment of the present application;

[0055] Figure 14 Schematic diagram of the converter topology in the prior art. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0057] The acquisition, storage, use and processing of data in the technical solution of this application comply with the relevant provisions of laws and regulations.

[0058] In one embodiment, see Figure 4 The novel bidirectional DC / DC converter topology structure includes a converter input end and a converter output end.

[0059] Among them, the input end of the converter includes multiple stages of input full-bridge converters connected in series; where the number of stages of the input full-bridge converter is 2N; the first-stage input full-bridge converter to the 2Nth-stage input full-bridge converter are connected in series in sequence; the positive pole of the DC end of the first-stage input full-bridge converter is connected to the positive pole of the high-voltage bus (UdcL+), and the negative pole of the DC end of the 2Nth-stage input full-bridge converter is connected to the negative pole of the high-voltage bus (UdcL-); the DC ends of the Nth-stage input full-bridge converter and the (N + 1)th-stage input full-bridge converter are both grounded; N is a positive integer and greater than 2;

[0060] The output end of the converter includes multiple stages of output full-bridge converters connected in parallel; the positive poles of the DC ends of each stage of output full-bridge converters are all connected to the positive pole of the low-voltage bus (UdcL+), and the negative poles of the DC ends of each stage of output full-bridge converters are all connected to the negative pole of the low-voltage bus (UdcL-).

[0061] It should be noted that Udc+ and Udc- are respectively the positive and negative poles of the DC side (also known as the DC link), Udc represents the voltage difference between the positive and negative poles of the DC side, Uac+ and Uac- respectively represent the positive and negative poles of the AC side, and Uac represents the voltage difference between the positive and negative poles of the AC side. Figure 4 FBC in

[0062] In one embodiment, referring to Figure 5 , in order to enable the new bidirectional DC / DC converter to complete fault ride-through, the present application provides a method for fault ride-through of a new bidirectional DC / DC converter, including:

[0063] S101: When it is determined based on the arm current of the converter that the converter has an external fault, control the converter to perform a short-term locking action;

[0064] S102: When it is detected that the external fault is eliminated, control the converter to perform grid connection and voltage recovery; where, when performing voltage recovery, based on the voltage drops borne by each sub-module in the converter, unlock each sub-module in sequence to achieve fault ride-through.

[0065] It can be understood that in the embodiments of the present application, the process of the new bidirectional DC / DC converter completing fault ride-through can be understood as a process of avoiding the invasion of external fault current through short-term locking after the converter has an external fault.

[0066] When the converter responds to an external fault, a short-term fault cross-current will occur in the converter. And when the converter has an internal fault, the converter itself will first lock and stop, and then search for the fault. The method for fault ride-through of the new bidirectional DC / DC converter provided by the present application mainly aims at the situation where the converter has an external fault.

[0067] In the prior art, for a conventional DC / DC topology converter (see Figure 14 ), if there is overcurrent at one port of its FBC (single full-bridge converter) or overcurrent in the module, the entire converter will start to lock out.

[0068] In the embodiment of the present application, the novel bidirectional DC / DC converter fault ride-through method is as follows: First, using the arm current as the judgment basis, the DC / DC converter can sense the occurrence of an external fault. It should be noted that when the arm current increases and exceeds the limit (exceeds the preset threshold), and the FBC sub-module does not issue an alarm signal, when these two conditions are both satisfied, the lockout protection of the converter will act. If it is determined that an external fault has occurred, then perform the protection action, that is, control all modules of the converter to perform a short-term lockout action. After the lockout, the short-circuit current path is cut off, but generally speaking, at this time, there is still magnetic isolation of the intermediate high-frequency transformer in the converter. Next, it is necessary to detect when the external fault is lifted, and after the external fault is lifted, control the converter to be connected to the grid and restore the voltage. Among them, when restoring the voltage, based on the voltage drop borne by each sub-module in the converter, unlock each sub-module in sequence to achieve fault ride-through.

[0069] As can be seen from the above description, the novel bidirectional DC / DC converter fault ride-through method provided by the present application can detect the lifting of the external fault, and when restoring the voltage, based on the voltage drop borne by each sub-module in the converter, unlock each sub-module in sequence, so that the sub-module with a lower voltage drop is unlocked first, and the sub-module with a higher voltage drop is unlocked later, and further enable the sub-module with a lower voltage drop to restore the voltage first, and the sub-module with a higher voltage drop to restore the voltage later, so as to ensure the safe operation of the converter equipment during the voltage restoration process, achieve the fault ride-through of the novel bidirectional DC / DC converter, and enable it to resume operation as soon as possible after the fault.

[0070] In one embodiment, see Figure 6 , the converter includes a power transfer side; the step of detecting the lifting of the external fault includes:

[0071] S201: Determine whether there is an abnormal situation in the voltage of the power transfer side; among them, the abnormal situation includes: three-phase voltage asymmetry abnormality, low voltage abnormality and voltage overlimit abnormality;

[0072] S202: If there is no abnormal situation, then determine whether the DC circuit breaker corresponding to the converter is in the closed position and determine whether the sub-module control board of the converter is powered normally;

[0073] S203: If it is determined that the DC circuit breaker corresponding to the converter is in the closed position and it is determined that the sub-module control board of the converter is powered normally, then determine that the external fault has been lifted.

[0074] It is understandable that it has been determined that the fault is external. After the bidirectional DC / DC converter is removed, the converter voltage needs to be restored. Specifically, the converter includes a support voltage side (located at the converter output end, which is the output end of active power) and a transfer power side (located at the converter input end, which is the input end of active power). Both sides need to restore voltage.

[0075] After the short-time blocking action is executed, the power transmission side needs to assume the responsibility of restoring the voltage. Specific process:

[0076] ① When the blocking is completed and the voltage needs to be restored, it is first necessary to determine whether the voltage on the power transmission side has the following abnormalities, including: three-phase voltage asymmetry, voltage too low (including voltage of 0) and voltage over-limit; it is also necessary to determine whether the DC circuit breaker is in the closed position;

[0077] ② Next, it is necessary to determine whether the power supply of the submodule control board is normal, and the capacitor voltage of the submodule cannot be lower than a set threshold.

[0078] If the above conditions are met, the external fault on this side can be considered to have been cleared.

[0079] It can be seen from the above description that the novel bidirectional DC / DC converter fault ride-through method provided in the present application can detect the removal of external faults.

[0080] In one embodiment, before controlling the converter to connect to the grid and restore voltage, the method further includes:

[0081] Each submodule is controlled to perform a chopping operation so that the high-frequency transformer corresponding to the converter conducts alternating current.

[0082] It can be understood that the transmission power side performs the grid connection operation. If the grid connection is not successful, it means that the upstream of this DC / DC converter is still faulty and needs to be further investigated; if the grid connection is successful and the grid connection is normal, then the FBC is started to perform the chopping operation, which can convert DC into AC, and the high-frequency transformer can conduct AC. The downstream FBC can rectify the AC into DC and then output it.

[0083] In one embodiment, see Figure 7 , based on the voltage drop of each submodule in the converter, unlocking each submodule in sequence to achieve fault ride-through includes:

[0084] S301: Determine the order of unlocking each submodule based on the voltage drop borne by each submodule in the converter;

[0085] S302: Unlock the submodules in the order to achieve fault ride-through.

[0086] It is understandable that this step is one of the core innovations of this application. Referring to Figure 4 the topology diagram of the novel DC / DC converter, the middle two groups of FBC sub-modules with relatively low voltage drops can be unlocked first (i.e., Figure 4 the two groups of FBC sub-modules with transformation ratios of m1:1, m2:1, m3:1, and m4:1 in

[0087] ), and the operations of steps S401 to S402 are performed; then the remaining FBC sub-modules with relatively high voltage drops on both sides are unlocked, and the operations of steps S401 to S402 are performed again.

[0088] In one embodiment, referring to Figure 8 , the converter includes a support voltage side, and the method further includes:

[0089] S401: Set a temporary voltage setting value for the sub-modules on the support voltage side;

[0090] S402: Perform a trial power transmission on the converter based on the result of the temporary voltage setting value to prevent a failure in the trial power transmission from causing a fault.

[0091] It is understandable that setting a "temporary voltage setting value" for the FBC on the "support voltage side" means setting a voltage threshold for a trial power transmission. The temporary voltage setting value is recommended to start from 0, and during the trial power transmission process, the voltage is gradually increased until it reaches 0.8 times the rated voltage to prevent a larger fault current caused by a failure in the trial power transmission.

[0092] After the external fault is removed and the fault ride-through strategy of the converter is started, the converter returns to the normal operating state, and the fault ride-through strategy stops running.

[0093] From the above description, it can be seen that the novel bidirectional DC / DC converter fault ride-through method provided by this application can perform a trial power transmission on the converter based on the result of the temporary voltage setting value to prevent a failure in the trial power transmission from causing a fault.

[0094] Based on the same inventive concept, an embodiment of the present application further provides a novel bidirectional DC / DC converter fault ride-through device, which can be used to implement the method described in the above embodiment, as described in the following embodiment. Since the principle of the novel bidirectional DC / DC converter fault ride-through device for solving problems is similar to that of the novel bidirectional DC / DC converter fault ride-through method, the implementation of the novel bidirectional DC / DC converter fault ride-through device can refer to the implementation of the method for determining software performance benchmarks, and the repeated parts will not be elaborated. As used hereinafter, the term "unit" or "module" can be a combination of software and / or hardware that can achieve a predetermined function. Although the systems described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware is also possible and contemplated.

[0095] In one embodiment, referring to Figure 9 , in order to enable the novel bidirectional DC / DC converter to complete fault ride-through, the present application provides a novel bidirectional DC / DC converter fault ride-through device, including: a blocking operation unit 901 and a grid connection restoration unit 902.

[0096] The blocking operation unit 901 is configured to control the converter to perform a short-term blocking operation when it is determined based on the arm current of the converter that an external fault has occurred in the converter;

[0097] The grid connection restoration unit 902 is configured to control the converter to perform grid connection and voltage restoration when it is detected that the external fault has been eliminated; wherein, when performing voltage restoration, based on the voltage drops borne by each sub-module in the converter, each sub-module is unlocked in sequence to achieve fault ride-through.

[0098] In one embodiment, referring to Figure 10 , the converter includes a power transmission side; the grid connection restoration unit 902 includes: an abnormality judgment module 1001, a breaker state judgment module 1002, a control board state judgment module 1003, and a fault elimination determination module 1004.

[0099] The abnormality judgment module 1001 is configured to judge whether there is an abnormal situation in the voltage of the power transmission side; wherein, the abnormal situation includes: three-phase voltage asymmetry abnormality, low voltage abnormality, and voltage over-limit abnormality;

[0100] The breaker state judgment module 1002 is configured to judge whether the DC breaker corresponding to the converter is in the closed position;

[0101] The control board state judgment module 1003 is configured to judge whether the power supply of the sub-module control board of the converter is normal;

[0102] The fault elimination determination module 1004 is configured to determine that the external fault has been eliminated.

[0103] In one embodiment, the converter fault ride-through device further includes:

[0104] A chopping execution unit, configured to control each sub-module to perform a chopping operation, so that an alternating current is conducted through a high-frequency transformer corresponding to the converter.

[0105] In one embodiment, referring to Figure 11 , the grid connection restoration unit 902 includes: an unlocking sequence determination module 1101 and an unlocking execution module 1102.

[0106] The unlocking sequence determination module 1101 is configured to determine the unlocking sequence of each sub-module based on the voltage drops borne by the sub-modules in the converter;

[0107] The unlocking execution module 1102 is configured to unlock each sub-module according to the sequence to achieve fault ride-through.

[0108] In one embodiment, referring to Figure 12 , the converter includes a support voltage side, and the device further includes: a voltage setting unit 1201 and a power transmission unit 1202.

[0109] The voltage setting unit 1201 is configured to perform temporary voltage setting on the sub-modules on the support voltage side;

[0110] The power transmission unit 1202 is configured to perform a trial power transmission on the converter based on the result of the temporary voltage setting, so as to prevent a failure in the trial power transmission from causing a fault.

[0111] From a hardware level, in order to enable the new bidirectional DC / DC converter to complete fault ride-through, this application provides an embodiment of an electronic device for implementing all or part of the content in the method for the new bidirectional DC / DC converter to perform fault ride-through. The electronic device specifically includes the following content:

[0112] A processor, a memory, a communication interface, and a bus; wherein, the processor, the memory, and the communication interface complete communication with each other through the bus; the communication interface is used to implement information transmission between the new bidirectional DC / DC converter fault ride-through device and related devices such as a core business system, a user terminal, and a related database. This logic controller can be a desktop computer, a tablet computer, a mobile terminal, etc., and this embodiment is not limited thereto. In this embodiment, this logic controller can be implemented with reference to the embodiments of the method for the new bidirectional DC / DC converter to perform fault ride-through and the embodiments of the new bidirectional DC / DC converter fault ride-through device, and the content thereof is incorporated herein, and the repeated parts will not be elaborated.

[0113] It can be understood that the user terminal may include a smart phone, a tablet electronic device, a network set-top box, a portable computer, a desktop computer, a personal digital assistant (PDA), a vehicle-mounted device, a smart wearable device, etc. Among them, the smart wearable device may include smart glasses, a smart watch, a smart bracelet, etc.

[0114] In practical applications, part of the novel bidirectional DC / DC converter fault ride-through method can be executed on the electronic device side as described above, or all operations can be completed in the client device. Specifically, it can be selected according to the processing capacity of the client device and the limitations of the user usage scenario, etc. This application does not make a limitation in this regard. If all operations are completed in the client device, the client device may further include a processor.

[0115] The above-mentioned client device may have a communication module (i.e., a communication unit), and can be communicatively connected to a remote server to realize data transmission with the server. The server may include a server on the task scheduling center side, and may also include a server of an intermediate platform in other implementation scenarios, such as a server of a third-party server platform communicatively linked to the task scheduling center server. The server may include a single computer device, or may include a server cluster composed of multiple servers, or a server structure of a distributed device.

[0116] Figure 13 It is a schematic block diagram of the system composition of the electronic device 9600 according to an embodiment of the present application. As Figure 13 shown, the electronic device 9600 may include a central processing unit 9100 and a memory 9140; the memory 9140 is coupled to the central processing unit 9100. It should be noted that this Figure 13 is exemplary; other types of structures may also be used to supplement or replace this structure to implement telecommunication functions or other functions.

[0117] In one embodiment, the function of the novel bidirectional DC / DC converter fault ride-through method may be integrated into the central processing unit 9100. Among them, the central processing unit 9100 may be configured to perform the following controls:

[0118] S101: When it is determined that the converter has an external fault based on the arm current of the converter, control the converter to perform a short-time locking action;

[0119] S102: When it is detected that the external fault is eliminated, control the converter to perform grid connection and voltage recovery; wherein, when performing voltage recovery, based on the voltage drops borne by each sub-module in the converter, unlock each sub-module in sequence to achieve fault ride-through.

[0120] From the above description, it can be seen that the new bidirectional DC / DC converter fault ride-through method provided in the present application can detect the removal of external faults, and when restoring the voltage, can unlock each sub-module in sequence based on the voltage drop borne by each sub-module in the converter, so that the sub-module borne by the lower voltage drop is unlocked first, and the sub-module borne by the higher voltage drop is unlocked later, thereby making the sub-module borne by the lower voltage drop perform voltage recovery first, and the sub-module borne by the higher voltage drop perform voltage recovery later, so as to ensure the operating safety of the converter equipment during the voltage recovery process, realize the fault ride-through of the new bidirectional DC / DC converter, and enable it to resume operation as soon as possible after the fault.

[0121] In another embodiment, the novel bidirectional DC / DC converter fault ride-through device can be configured separately from the central processing unit 9100. For example, the data composite transmission device novel bidirectional DC / DC converter fault ride-through device can be configured as a chip connected to the central processing unit 9100, and the function of the novel bidirectional DC / DC converter fault ride-through method can be realized through the control of the central processing unit.

[0122] like Figure 13 As shown, the electronic device 9600 may also include: a communication module 9110, an input unit 9120, an audio processor 9130, a display 9160, and a power supply 9170. It is worth noting that the electronic device 9600 does not necessarily have to include Figure 13 In addition, the electronic device 9600 may also include Figure 13 For components not shown, reference may be made to the prior art.

[0123] like Figure 13 As shown, the central processing unit 9100 is sometimes also referred to as a controller or an operation control, and may include a microprocessor or other processor device and / or logic device. The central processing unit 9100 receives input and controls the operation of various components of the electronic device 9600.

[0124] The memory 9140 may be, for example, one or more of a cache, a flash memory, a hard drive, a removable medium, a volatile memory, a non-volatile memory or other suitable devices. The above-mentioned information related to the failure may be stored, and a program for executing the relevant information may also be stored. The CPU 9100 may execute the program stored in the memory 9140 to implement information storage or processing, etc.

[0125] The input unit 9120 provides input to the central processing unit 9100. The input unit 9120 is, for example, a key or a touch input device. The power supply 9170 is used to provide power to the electronic device 9600. The display 9160 is used to display display objects such as images and texts. The display may be, for example, an LCD display, but is not limited thereto.

[0126] The memory 9140 can be a solid-state memory, for example, a read-only memory (ROM), a random access memory (RAM), a SIM card, etc. It can also be a memory that stores information even when power is off, can be selectively erased and has more data. Examples of such a memory are sometimes referred to as EPROMs, etc. The memory 9140 can also be some other type of device. The memory 9140 includes a buffer memory 9141 (sometimes referred to as a buffer). The memory 9140 can include an application / function storage unit 9142 that is used to store application programs and function programs or the processes for operating the electronic device 9600 by the central processing unit 9100.

[0127] The memory 9140 can also include a data storage unit 9143 that is used to store data, such as contacts, digital data, pictures, sounds, and / or any other data used by the electronic device. The driver storage unit 9144 of the memory 9140 can include various drivers of the electronic device for communication functions and / or for performing other functions of the electronic device (such as a messaging application, an address book application, etc.).

[0128] The communication module 9110 is a transmitter / receiver 9110 that transmits and receives signals via the antenna 9111. The communication module (transmitter / receiver) 9110 is coupled to the central processing unit 9100 to provide input signals and receive output signals, which can be the same as in the case of a conventional mobile communication terminal.

[0129] Based on different communication technologies, multiple communication modules 9110 can be provided in the same electronic device, such as a cellular network module, a Bluetooth module, and / or a wireless local area network module, etc. The communication module (transmitter / receiver) 9110 is also coupled to the speaker 9131 and the microphone 9132 via the audio processor 9130 to provide an audio output via the speaker 9131 and receive an audio input from the microphone 9132, thereby implementing normal telecommunication functions. The audio processor 9130 can include any suitable buffer, decoder, amplifier, etc. In addition, the audio processor 9130 is also coupled to the central processing unit 9100, so that it is possible to record on the local machine through the microphone 9132 and play the sound stored on the local machine through the speaker 9131.

[0130] An embodiment of the present application also provides a computer-readable storage medium capable of implementing all steps of the novel bidirectional DC / DC converter fault ride-through method in which the execution entity in the above embodiment is a server or a client. A computer program is stored on the computer-readable storage medium. When the computer program is executed by a processor, all steps of the novel bidirectional DC / DC converter fault ride-through method in which the execution entity in the above embodiment is a server or a client are implemented. For example, when the processor executes the computer program, the following steps are implemented:

[0131] S101: When it is determined based on the arm current of the converter that an external fault has occurred in the converter, control the converter to perform a short-term locking action;

[0132] S102: When it is detected that the external fault has been eliminated, control the converter to perform grid connection and voltage recovery; wherein, when performing voltage recovery, based on the voltage drops borne by each sub-module in the converter, unlock each sub-module in sequence to achieve fault ride-through.

[0133] As can be seen from the above description, the novel bidirectional DC / DC converter fault ride-through method provided by the present application can detect the elimination of an external fault, and when performing voltage recovery, based on the voltage drops borne by each sub-module in the converter, unlock each sub-module in sequence, so that the sub-modules bearing lower voltage drops are unlocked first, and the sub-modules bearing higher voltage drops are unlocked later, and further enable the sub-modules bearing lower voltage drops to perform voltage recovery first, and the sub-modules bearing higher voltage drops to perform voltage recovery later, so as to ensure the safe operation of the converter device during the voltage recovery process, achieve the fault ride-through of the novel bidirectional DC / DC converter, and enable it to resume operation as soon as possible after a fault.

[0134] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a device, or a computer program product. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0135] This application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (devices), and computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be realized by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate a device for realizing the functions specified in the Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0136] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including an instruction device, and the instruction device realizes the functions specified in the Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0137] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Therefore, the instructions executed on the computer or other programmable device provide steps for realizing the functions specified in the Figure 1 one or more flows and / or blocks Figure 1 one or more blocks.

[0138] Specific embodiments are applied in this application to elaborate on the principles and implementation manners of this application. The description of the above embodiments is only used to help understand the method and its core idea of this application; at the same time, for those of ordinary skill in the art, according to the idea of this application, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to this application.

Claims

1. A novel fault ride-through method for a bidirectional DC / DC converter, characterized in that, Including: When it is determined that an external fault has occurred in the converter based on the arm current of the converter, controlling the converter to perform a short-time blocking operation; When it is detected that the external fault has been eliminated, controlling the converter to perform grid connection and voltage recovery; wherein, when performing voltage recovery, based on the voltage drops borne by each sub-module in the converter, unlocking each sub-module in sequence to achieve fault ride-through; wherein, the unlocking each sub-module in sequence based on the voltage drops borne by each sub-module in the converter to achieve fault ride-through includes: determining the unlocking order of each sub-module based on the voltage drops borne by each sub-module in the converter; unlocking each sub-module in accordance with the order to achieve fault ride-through; specifically, first unlocking the middle two groups of sub-modules with relatively low voltage drops in the new type of bidirectional DC / DC converter; then unlocking the remaining sub-modules with relatively high voltage drops on both sides; Wherein, the topology structure of the new type of bidirectional DC / DC converter includes: a converter input end and a converter output end; Wherein, the converter input end includes a multi-stage input full-bridge converter connected in series; wherein, the number of stages of the input full-bridge converter is 2N; the first-stage input full-bridge converter to the 2Nth-stage input full-bridge converter are connected in series in sequence; the DC positive pole of the first-stage input full-bridge converter is connected to the positive pole of the high-voltage bus, and the DC negative pole of the 2Nth-stage input full-bridge converter is connected to the negative pole of the high-voltage bus; the DC ends of the Nth-stage input full-bridge converter and the (N + 1)th-stage input full-bridge converter are both grounded; N is a positive integer and greater than 2; The converter output end includes a multi-stage output full-bridge converter connected in parallel; the DC positive poles of each stage of the output full-bridge converter are all connected to the positive pole of the low-voltage bus, and the DC negative poles of each stage of the output full-bridge converter are all connected to the negative pole of the low-voltage bus.

2. The converter fault ride-through method according to claim 1, wherein, The converter includes a power transfer side; the step of detecting that the external fault has been eliminated includes: Judging whether there is an abnormal situation in the voltage of the power transfer side; If there is no abnormal situation, then judging whether the DC circuit breaker corresponding to the converter is in the closed position and judging whether the sub-module control board of the converter is powered normally; If it is determined that the DC circuit breaker corresponding to the converter is in the closed position and it is determined that the sub-module control board of the converter is powered normally, then it is determined that the external fault has been eliminated.

3. The converter fault ride-through method according to claim 1, characterized in that Before controlling the converter to perform grid connection and voltage recovery, it further includes: Controlling each sub-module to perform chopping operation.

4. The converter fault ride-through method according to claim 1, characterized in that The converter includes a support voltage side, and the method further includes: Performing temporary voltage setting for the sub-modules on the support voltage side; Performing a trial power transmission for the converter based on the result of the temporary voltage setting.

5. A novel bidirectional DC / DC converter fault ride-through device, characterized in that, Including: A blocking action unit, configured to control the converter to perform a short-time blocking operation when it is determined that an external fault has occurred in the converter based on the arm current of the converter; A grid-connection recovery unit is used to control the converter to connect to the grid and restore the voltage when it is detected that the external fault is removed; when it is detected that the external fault is removed, the converter is controlled to connect to the grid and restore the voltage; wherein, when the voltage is restored, the submodules in the converter are unlocked in sequence based on the voltage drop borne by each submodule in the converter to achieve fault ride-through; wherein, the module unlocking unit includes: an unlocking sequence determination module, which is used to determine the unlocking sequence of each submodule based on the voltage drop borne by each submodule in the converter; an unlocking execution module, which is used to unlock each submodule in the sequence to achieve fault ride-through; specifically, first unlock the two middle groups of submodules with relatively low voltage drop in the novel bidirectional DC / DC converter; and then unlock the remaining submodules with relatively high voltage drop on both sides; Among them, the novel bidirectional DC / DC converter topology structure includes: a converter input end and a converter output end; The input end of the converter includes a multi-stage input full-bridge converter connected in series; the number of stages of the input full-bridge converter is 2N; the first-stage input full-bridge converter to the 2N-stage input full-bridge converter are connected in series in sequence; the positive pole of the DC end of the first-stage input full-bridge converter is connected to the positive pole of the high-voltage bus, and the negative pole of the DC end of the 2N-stage input full-bridge converter is connected to the negative pole of the high-voltage bus; the DC end of the N-stage input full-bridge converter and the DC end of the N+1-stage input full-bridge converter are both grounded; N is a positive integer and is greater than 2; The output end of the converter includes a multi-stage output full-bridge converter connected in parallel; the DC positive pole of each stage of the output full-bridge converter is connected to the positive pole of the low-voltage bus, and the DC negative pole of each stage of the output full-bridge converter is connected to the negative pole of the low-voltage bus.

6. The converter fault ride-through device according to claim 5, characterized in that, The converter includes a power transmission side; the grid-connected recovery unit includes: An abnormality judgment module, used to judge whether the voltage on the power transmission side is abnormal; A circuit breaker status judgment module, used to judge whether the DC circuit breaker corresponding to the converter is in the closed position; A control board status judgment module, used to judge whether the submodule control board of the converter is powered normally; The fault elimination determination module is used to determine that the external fault has been eliminated.

7. The converter fault ride-through device according to claim 5, wherein, Also includes: The chopping execution unit is used to control each submodule to perform a chopping operation.

8. The converter fault ride-through device according to claim 5, characterized in that, The converter comprises a supporting voltage side, and the device further comprises: A voltage setting unit, used for setting a temporary voltage setting for the submodule on the supporting voltage side; A power transmission unit is used to test power transmission to the converter based on the result of temporary voltage setting.

9. An electronic device, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, When the processor executes the program, the steps of the novel bidirectional DC / DC converter fault ride-through method according to any one of claims 1 to 4 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, the steps of the novel bidirectional DC / DC converter fault ride-through method according to any one of claims 1 to 4 are implemented.

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