Black start method, power conversion system, control device, and storage medium

Abstract

The application provides a black start method of a power conversion system, the power conversion system, a control device and a storage medium. The power conversion system comprises at least two power converters, and the alternating current sides of each of the at least two power converters are connected in parallel. The power converter comprises a controller. The method comprises the following steps: the controller acquires a detection result of the power converter, and controls the power converter to execute a corresponding black start process according to the detection result. The detection result is used to indicate whether there is voltage on the alternating current side of the power converter. The corresponding black start process of the power converter comprises a corresponding black start process of a master or a corresponding black start process of a slave. In the application, the power conversion system can actively judge the master-slave roles of the at least two power converters, so that the corresponding black start process is executed, and the system cost is effectively saved.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and more specifically, to a black-start method for a power conversion system, a power conversion system, a control device, and a storage medium. Background Technology

[0002] The process of restoring a power conversion system to normal operation after a shutdown is called a black start process. Related technologies use black start controllers to control the power conversion system to perform the black start process, but this black start method has the problem of high cost. Summary of the Invention

[0003] This application provides a black-start method, a power conversion system, a control device, and a storage medium for a power conversion system, thereby reducing system costs. The various aspects involved in this application's embodiments are described below.

[0004] A first aspect provides a black-start method for a power conversion system, the power conversion system including at least two power converters, the AC side of each of the at least two power converters being connected in parallel, each power converter including a controller, the method including: the controller being configured to acquire a detection result of the power converter, and, based on the detection result, control the power converter to execute a corresponding black-start process; wherein, the detection result is used to indicate whether there is voltage on the AC side of the power converter, and the black-start process corresponding to the power converter includes a black-start process corresponding to a master unit or a black-start process corresponding to a slave unit.

[0005] As one possible implementation, the method further includes: if the detection result indicates that there is voltage on the AC side of the power converter, the controller is configured to control the power converter to execute the black start process corresponding to the slave device according to the detection result; if the detection result indicates that there is no voltage on the AC side of the power converter and the startup time of the power converter has arrived, the controller is configured to control the power converter to execute the black start process corresponding to the master device according to the detection result.

[0006] As one possible implementation, the method further includes: the controller, configured to determine the startup time of the power converter based on the reception time of the black start signal and a preset address parameter; wherein the value of the address parameter is used to indicate the startup sequence of the power converter.

[0007] As one possible implementation, the address parameter can take the value of any positive integer from 1 to N, where N represents the number of power converters.

[0008] As one possible implementation, the method further includes: if the power converter executes the black boot process corresponding to the host, the controller updates the value of the address parameter so that the power converter is the first to be started in the next black boot process.

[0009] As one possible implementation, the method further includes: if the power converter executes the black start process corresponding to the host, the controller reports fault information of at least one power converter preceding the power converter, the fault information being used to indicate that the at least one power converter has a fault.

[0010] Secondly, a power conversion system is provided, the power conversion system including at least two power converters, the power conversion system including: a control module, used to acquire the detection results of the power converters, and control the power converters to execute a corresponding black start process according to the detection results; wherein, the detection results are used to indicate whether there is voltage on the AC side of the power converter, and the black start process corresponding to the power converter includes a black start process corresponding to the master unit or a black start process corresponding to the slave unit.

[0011] As one possible implementation, the power conversion system further includes: if the detection result indicates that there is voltage on the AC side of the power converter, the control module is configured to control the power converter to execute the black start process corresponding to the slave device according to the detection result; if the detection result indicates that there is no voltage on the AC side of the power converter and the startup time of the power converter has arrived, the control module is configured to control the power converter to execute the black start process corresponding to the master device according to the detection result.

[0012] As one possible implementation, the control module is used to determine the start-up time of the power converter based on the reception time of the black start signal and a preset address parameter; wherein the value of the address parameter is used to indicate the start-up sequence of the power converter.

[0013] As one possible implementation, the address parameter can take the value of any positive integer from 1 to N, where N represents the number of power converters.

[0014] As one possible implementation, the power conversion system further includes an update module, configured to update the value of the address parameter if the power converter executes the black boot process corresponding to the host, so that the power converter is the first to be started in the next black boot process.

[0015] As one possible implementation, the power conversion system further includes a reporting module, used to report fault information of at least one power converter preceding the power converter if the power converter executes the black start process corresponding to the host, the fault information being used to indicate that the at least one power converter has a fault.

[0016] Thirdly, a power conversion system is provided, the power conversion system comprising: at least two power converters, each of the at least two power converters being configured to perform the method as described in the first aspect or any implementation thereof.

[0017] Fourthly, a control device is provided, the control device including a processor and a memory, the memory being used to store programs, instructions or code, and the processor being used to execute the programs, instructions or code in the processor to perform the method as described in the first aspect or any implementation thereof.

[0018] Fifthly, a computer-readable storage medium is provided for storing a computer program, which is loaded by a processor to execute the method as described in the first aspect or any implementation thereof.

[0019] Related technologies use a black-start controller to assign master / slave roles to power converters, thereby controlling the black-start process of the power conversion system. Unlike related technologies, in this embodiment, the power converter can actively determine its master / slave role based on its startup time and external voltage, thus executing the corresponding black-start procedure. Therefore, this embodiment does not require an additional black-start controller in the power conversion system, thereby saving system costs. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the architecture of a power conversion system applicable to embodiments of this application.

[0021] Figure 2 This is a schematic diagram of a power conversion system based on a black-start controller, provided by related technologies.

[0022] Figure 3 This is a schematic flowchart of a black-start method for a power conversion system provided in an embodiment of this application.

[0023] Figure 4 This is a schematic flowchart of a black-start method for a power conversion system provided in another embodiment of this application.

[0024] Figure 5 This is a schematic diagram of the power conversion system provided in one embodiment of this application.

[0025] Figure 6 This is a schematic diagram of the structure of a control device provided in an embodiment of this application. Detailed Implementation

[0026] The technical solutions in 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.

[0027] Hereinafter, 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, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of embodiments of this disclosure, unless otherwise stated, "a plurality of" means two or more. Furthermore, the use of "based on" or "according to" implies openness and inclusiveness, because processes, steps, calculations, or other actions "based on" or "according to" one or more conditions or values ​​may in practice be based on additional conditions or exceeding values.

[0028] The embodiments of this application can be applied to power conversion systems. This power conversion system can also be called a power station. In some implementations, the power conversion system can be a microgrid system. The embodiments of this application do not specifically limit the type of power conversion system. For example, the power conversion system can be an energy storage system. Or, for example, the power conversion system can refer to a photovoltaic system.

[0029] To make it easier to understand, let's first combine... Figure 1 The system structure of the power conversion system mentioned in the embodiments of this application is illustrated with examples. See [link to relevant documentation]. Figure 1The power conversion system 10 may include DC power supplies 12a-12n. This application embodiment does not specifically limit the type of DC power supplies 12a-12n. For example, DC power supplies 12a-12n may include photovoltaic modules. Alternatively, DC power supplies 12a-12n may include one or more batteries. In addition to DC power supplies 12a-12n, the power conversion system 10 may also include power converters 14a-14n. These power converters 14a-14n may be, for example, photovoltaic inverters or energy storage converters. Power converters 14a-14n may have a DC side and an AC side. The DC side of the power converters 14a-14n may be connected to the DC power supplies 12a-12n, and the AC side may be connected to the power grid. For example, the AC side of the power converter can be connected to the power grid in parallel. The power converters 14a-14n can convert the DC power output from the DC power supplies 12a-12n into AC power, and then provide this AC power to the power grid. Of course, in some implementations, the power conversion system 10 can also operate in off-grid mode, meaning that the power converters 14a to 14n can also supply power to the load (not shown in the figure). For example, the power converters 14a to 14n can preferentially convert the DC power output from the DC power supplies 12a to 12n into AC power to supply power to the load. When the electrical energy provided by the DC power supplies 12a to 12n exceeds the load's demand for electrical energy, the power converters 14a to 14n can feed the excess electrical energy into the grid and provide it to other users through the grid.

[0030] The process of restoring normal operation after a power conversion system (such as the power conversion system 10 mentioned above) has been shut down can be called a black start process.

[0031] During black start, multiple power converters (or at least two) typically need to start in a specific sequence. Taking grid voltage establishment as an example, one power converter can be started first to establish the grid voltage. This first power converter is usually referred to as the master converter. Once the grid voltage reaches a certain value, the other power converters can start sequentially as slave converters. During startup, slave converters usually need to perform pre-synchronization networking. The purpose of pre-synchronization networking is to achieve phase tracking and synchronization with the grid voltage, thereby suppressing the inrush current at the moment of grid connection.

[0032] As described above, in order to support the startup of multiple power converters according to a specific timing sequence, it is necessary to assign master and slave roles to these power converters. To address this issue, relevant technologies mainly provide two solutions, which are described in detail below.

[0033] Some related technologies manually configure master-slave roles for multiple power converters. That is, before a black start, the master-slave roles of multiple power converters are manually set. Once the power conversion system needs to perform a black start, the multiple power converters in the system must start sequentially according to their manually set roles. However, this master-slave role configuration method has a lack of flexibility. If the master fails, it is impossible to reselect a master, causing the entire power conversion system to fail to start.

[0034] Besides manually configuring the master and slave roles in a power conversion system, some related technologies introduce black-start controllers to improve the flexibility of the black-start process. See also... Figure 2 The power conversion system includes power converters 14a to 14n and a black-start controller 16. This black-start controller 16 is connected to the power converters 14a to 14n, allowing it to control the black-start process of the power converters 14a to 14n. For example, during black-start, the black-start controller 16 can set power converter 14a as the master, allowing it to start first to establish voltage. If power converter 14a fails to start (e.g., a fault occurs), the black-start controller 16 can assign the master role to power converter 14b. As described above, the introduction of the black-start controller 16 allows the power conversion system to start smoothly even in the event of a master failure, thus improving the flexibility of the black-start process. However, the introduction of the black-start controller 16 increases the complexity of the system structure and also increases system cost.

[0035] To address the aforementioned issues, this application provides embodiments that configure different startup times for multiple power converters. This allows each power converter to proactively determine its master / slave role based on its startup time and external voltage, thereby executing the corresponding black-start process. The implementation method provided by this application not only allows for flexible adjustment of the master / slave roles of the power converters but also eliminates the need for a black-start controller in the power conversion system, thus saving system costs.

[0036] The following text combines Figure 3 This application provides a detailed description of the black-start method for a power conversion system provided in its embodiments. For ease of understanding, Figure 3 Described from the perspective of a power conversion system, the power conversion system 10 includes at least two power converters, and each power converter 14 includes a controller 142.

[0037] See Figure 3In step S310, the controller 142 is used to obtain the detection result of the power converter and, based on the detection result, control the power converter to execute the corresponding black start process.

[0038] In some implementations, the detection result is used to indicate whether voltage exists on the AC side of the power converter. In this embodiment, the type of voltage present on the AC side of the power converter is not limited. For example, the voltage type present on the AC side of the power converter can be grid voltage or load voltage. Taking grid voltage as an example, if grid voltage is present, it indicates that the power conversion system has established a power grid; if grid voltage is not present, it indicates that the power conversion system has not yet established a power grid.

[0039] In some implementations, the black start process for the power converter includes either the black start process for the host or the black start process for the slave.

[0040] Different voltage detection results lead to different black-start procedures for the power converter. In some implementations, if the detection result indicates the presence of voltage on the AC side of the power converter, the controller controls the power converter to execute the black-start procedure corresponding to the slave unit based on the detection result. The black-start procedure corresponding to the slave unit can differ somewhat from that corresponding to the master unit. Taking the voltage detected as the grid voltage as an example, since the grid voltage has already been established when the slave unit starts up, the slave unit can first perform pre-synchronization networking. The purpose of pre-synchronization networking is to achieve phase tracking and synchronization of the grid voltage to suppress the inrush current at the moment of grid connection. When the output voltage on the AC side of the slave unit is synchronized with the grid voltage, the slave unit can be used in grid connection.

[0041] In other implementations, if the detection result indicates that there is no voltage on the AC side of the power converter, the power converter can determine its master / slave role based on the detection result and its own startup time, and thus execute the corresponding black-start procedure. Taking the voltage in the detection result as the grid voltage as an example, if the detection result indicates that there is no grid voltage on the AC side of the power converter, and the startup time of the power converter has arrived, the controller is used to control the power converter to execute the black-start procedure corresponding to the master based on the detection result. The black-start procedure corresponding to the master may include establishing the grid voltage. The embodiments of this application do not specifically limit the method of establishing the grid voltage. For example, the power converter can control the output voltage on the AC side according to a certain strategy, so that the output voltage on the AC side gradually rises to the preset grid voltage.

[0042] Regarding the "start-up time" mentioned above, this application embodiment does not limit the method for determining the start-up time of the power converter. In some implementations, the power conversion system can determine the start-up time of the power converter based on the black-start signal. In other words, the start-up time of the power converter is determined in response to the black-start signal. The black-start signal can be triggered before the power conversion system receives it. This application does not specifically limit the triggering method of the black-start signal. For example, the power conversion system may include an energy management system (EMS), which can send a black-start signal to the power converter when the power conversion system needs to perform a black start. Alternatively, the power conversion system can be equipped with a start button, allowing the user to send a black-start signal to the power converter by pressing the start button.

[0043] In this embodiment, the power conversion system includes different power converters with different startup times. There are several ways to set different startup times for different power converters. For example, different power converters can pre-store different time interval parameters. When different power converters simultaneously receive the black start signal, they can start according to their respective time interval parameters, thus making the startup times of the different power converters different. Of course, other rules or algorithms can also be used to make the startup times of different power converters different.

[0044] The following section presents a method for calculating the startup time based on address parameters.

[0045] First, address parameters can be set for the power converters in the power conversion system. The value of this address parameter indicates the startup order of the power converters. In some implementations, the address parameter value indicates the startup order of a particular power converter relative to the other power converters in the power conversion system. For example, the smaller the address parameter value of a power converter, the earlier its startup order is relative to the other power converters in the system. During black start, the controller in each power converter can determine its startup time based on the black start signal reception time and the pre-set address parameters. For example, the address parameters of the power converter can be converted into a time interval relative to the black start signal reception time using a certain algorithm, and its startup time can be determined based on this time interval. Because different power converters have different address parameter values, the calculated time intervals differ, resulting in different startup times for each power converter.

[0046] For example, if the black start signal is received at time a, the power conversion system has N power converters, and the address parameters of the N power converters are configured from 1 to N (N represents the number of power converters), and the address parameter of a certain power converter is i, where i is any positive integer from 1 to N. In this case, the start time T of this power converter is... i The time interval between time a and time a can be: T i = (i-1)*t. Where t represents the delay time between the start-up times of different power converters. The purpose of setting this delay time is to ensure that the previous power converter has completed its start-up when the next power converter starts up.

[0047] As can be seen from the example above, after receiving the black start signal, the power converter with address parameter value 1 will start first. If the power converter with address parameter value 1 starts successfully, the other power converters will start as slaves. If the power converter with address parameter value 1 fails to start (e.g., due to a fault), the power converter with address parameter value 2 will start as the master, and so on.

[0048] Considering that there may be faulty power converters (hereinafter referred to as faulty units) that have not started among the multiple power converters, the presence of faulty units may affect the startup efficiency of the subsequent black start process.

[0049] For example, suppose a power conversion system includes three power converters: Power Converter 1, Power Converter 2, and Power Converter 3. The startup sequence of Power Converter 1, Power Converter 2, and Power Converter 3 is: Power Converter 1 → Power Converter 2 → Power Converter 3. During the current black start process, Power Converter 1 does not detect its AC side voltage and reaches its startup time but fails to start. Then, Power Converter 2 reaches its startup time and acts as the master, executing the corresponding black start procedure. Power Converter 3 reaches its startup time and acts as the slave, executing the corresponding black start procedure. For Power Converter 1, since its AC side has no voltage and it has reached its startup time but still fails to start, this indicates a fault in Power Converter 1.

[0050] After a period of time, suppose the power conversion system shuts down again and needs to perform the black start process again. In this black start process, if the startup sequence is still followed, power converter 2 will still have to wait for power converter 1, which has been confirmed to have failed, to start first. This will inevitably reduce the startup efficiency of the black start process.

[0051] To address the above problems, this application proposes a method for dynamically updating address parameters to improve the startup efficiency of the black boot process.

[0052] Suppose a power conversion system consists of multiple power converters, including one power converter and at least one power converter whose startup sequence precedes that power converter. If the power converter executes the black boot process corresponding to the host, it indicates that at least one power converter whose startup sequence precedes that power converter has failed. In this case, the controller in the power converter can update the address parameter value of the power converter (for example, setting the address parameter value of the power converter to 1), so that the power converter is the first to be started in the next black boot process. In this way, when the next black boot process arrives, the power converter will be started first without waiting for the failed machine to start, avoiding wasted time.

[0053] For example, suppose the power conversion system includes three power converters: power converter 1, power converter 2, and power converter 3. The address parameters of power converters 1, 2, and 3 are 1, 2, and 3, respectively. Therefore, the startup sequence of power converters 1, 2, and 3 is: power converter 1 → power converter 2 → power converter 3. During the current black start process, power converter 1 does not detect its AC side voltage and reaches its startup time but fails to start. Then, power converter 2 reaches its startup time and acts as the master to execute the corresponding black start process, and power converter 3 reaches its startup time and acts as the slave to execute the corresponding black start process. For power converter 1, since its AC side has no voltage and it has also reached its startup time but still fails to start, it indicates that power converter 1 is faulty. Therefore, after the black start is completed, the address parameter value of power converter 2 can be updated to 1.

[0054] After a period of time, assuming the power conversion system shuts down again, the black boot process needs to be executed again. During this black boot process, the address parameter of power converter 2 is 1, and it will be started as the master with priority, thus improving the startup efficiency of the black boot process.

[0055] In some implementations, if a power converter system comprises multiple power converters, including a specific power converter and at least one power converter that precedes it in the startup sequence, and the specific power converter acts as the master during the current black start process, then it indicates that at least one power converter preceding the specific power converter in the startup sequence has failed. In this case, the power conversion system (such as the controller within the power converter) can report the fault information. For example, the controller can send an indication to the EMS (Electronic Management System) to indicate that at least one power converter preceding the specific power converter has failed, thereby enabling the user to repair or replace that at least one power converter as soon as possible.

[0056] For example, suppose the power conversion system includes three power converters: Power Converter 1, Power Converter 2, and Power Converter 3. The startup sequence of Power Converter 1, Power Converter 2, and Power Converter 3 is: Power Converter 1 → Power Converter 2 → Power Converter 3. During the current black start process, Power Converter 1 does not detect its AC side voltage and reaches its startup time but fails to start. Then, Power Converter 2, upon reaching its startup time, acts as the master and executes the corresponding black start process, and Power Converter 3, upon reaching its startup time, acts as the slave and executes the corresponding black start process. For Power Converter 1, since its AC side has no voltage and it has also reached its startup time but still fails to start, this indicates that Power Converter 1 is faulty. Therefore, after the black start is complete, Power Converter 2 can somehow alert the user that Power Converter 1 has failed and needs maintenance.

[0057] As mentioned earlier, during black start, the power converter can determine its master / slave role by detecting the presence of voltage on the AC side. This application does not specifically limit the voltage detection method. For example, the power converter may include a voltage detection circuit to detect the presence of voltage on its AC side. This voltage detection circuit can be, for example, a voltage sensor. Furthermore, this application does not limit the timing of voltage detection; the power converter can continuously perform voltage detection during black start until its own start-up time is reached. Alternatively, the power converter may only begin voltage detection when its start-up time is about to arrive.

[0058] The embodiments of this application will be described in more detail below with specific examples, taking grid voltage as an example. In the following examples, Figure 4 The embodiments of this application are provided merely to help those skilled in the art understand them, and are not intended to limit the embodiments of this application to the specific numerical values ​​or specific scenarios illustrated. Those skilled in the art will obviously be able to make various equivalent modifications or variations based on the examples given, and such modifications or variations also fall within the scope of the embodiments of this application.

[0059] Figure 4 An example diagram illustrating the black start method provided in an embodiment of this application. Figure 4 In the example, assume the power conversion system includes N power converters, the black start address range of the N power converters is 1 to N, the black start address of a certain power converter is i, where i belongs to any positive integer from 1 to N, the interval between sequentially starting the power converters is t, and the black start signal is received at 00:00. Then the start time T of the power converter is... i For: T i = (i-1)*t.

[0060] See Figure 4 The black boot method may include the following steps: S401 to S406.

[0061] In step S401: When the black start of the power converter begins, the black start role of all N power converters is defaulted to slave.

[0062] In step S402: Determine whether there is grid voltage on the AC side of the power converter. If there is no grid voltage on the AC side of the power converter, proceed to step S403; if there is grid voltage on the AC side of the power converter, proceed to step S405.

[0063] In step S403: Determine whether the power converter's startup time has been reached. The power converter's startup time is calculated based on its black startup address: T i For: T i = (i-1)*t. If the power converter's startup time has not arrived, proceed to step S402; if the power converter's startup time has arrived, proceed to step S404.

[0064] In step S404: Set the role of the power converter as the host.

[0065] In step S405: Set the power converter to a slave role.

[0066] In step S406: The roles of the master and slave machines in the black boot process are determined, and the corresponding black boot process can be executed.

[0067] As can be seen from the above description, compared to the traditional manual configuration and selection of master / slave startup, this solution determines the startup sequence of each power converter based on the black start signal reception time, the pre-set address parameters for multiple power converters, and the interval between sequential startups. This enables automatic allocation of master / slave roles, thereby reducing the manual cost of the black start process and improving its flexibility. Compared to the traditional solution that selects master / slave startup through a black start controller, this solution determines the startup sequence of the power converters based on their startup signals, enabling automatic allocation of master / slave roles without the need for a black start controller, thus saving control costs during the black start process.

[0068] The above text combined Figures 1 to 4 The method embodiments of this application have been described in detail below, in conjunction with... Figures 5 to 6 The apparatus embodiments of this application are described in detail below. It should be understood that the descriptions of the method embodiments correspond to the descriptions of the apparatus embodiments; therefore, any parts not described in detail can be referred to the foregoing method embodiments.

[0069] Figure 5This is a schematic diagram of a power conversion system provided in one embodiment of this application. See also... Figure 5 The power conversion system 50 may include a control module 51.

[0070] The control module 51 is used to acquire the detection result of the power converter and control the power converter to execute the corresponding black start process according to the detection result; wherein, the detection result is used to indicate whether there is voltage on the AC side of the power converter, and the black start process corresponding to the power converter includes the black start process corresponding to the master or the black start process corresponding to the slave.

[0071] Optionally, the power conversion system 50 further includes: if the detection result indicates that there is voltage on the AC side of the power converter, then the control module 51 is used to control the power converter to execute the black start process corresponding to the slave device according to the detection result; if the detection result indicates that there is no voltage on the AC side of the power converter and the start-up time of the power converter has arrived, then the control module 51 is used to control the power converter to execute the black start process corresponding to the master device according to the detection result.

[0072] Optionally, the control module 51 is used to determine the start time of the power converter based on the receiving time of the black start signal and a preset address parameter; wherein the value of the address parameter is used to indicate the start sequence of the power converter.

[0073] Optionally, the address parameter can take the value of any positive integer from 1 to N, where N represents the number of power converters.

[0074] Optionally, the power conversion system 50 further includes an update module, configured to update the value of the address parameter if the power converter executes the black boot process corresponding to the host, so that the power converter is the first to be started in the next black boot process.

[0075] Optionally, the power conversion system 50 further includes a reporting module, configured to report fault information of at least one power converter preceding the power converter if the power converter executes the black start process corresponding to the host, the fault information being used to indicate that the at least one power converter has a fault.

[0076] This application also provides a power conversion system, which can be any type of power conversion system mentioned above, such as... Figure 1 The power conversion system shown herein includes at least two power converters, each of which is configured to perform any of the black-start methods mentioned above.

[0077] This application embodiment also provides a control device 60, which may include a memory 61 and a processor 62. The processor 62 may be connected to the power converter 14 and may drive the power converter 14. Figure 6 As shown, memory 61 can be random access memory (RAM), flash memory, read-only memory (ROM), EPROM, non-volatile read-only memory (Electronic Programmable ROM), register, hard disk, removable disk, etc.

[0078] The memory 61 can store computer instructions. When the computer instructions stored in the memory 61 are executed by the processor 62, the processor 62 can be used to execute the black-start method in the power conversion system. The memory 61 can also store data.

[0079] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any other combination. When implemented in software, it can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this disclosure are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a machine-readable storage medium or transmitted from one machine-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The machine-readable storage medium can be any available medium accessible to a computer or a data storage device such as a server or data center that integrates one or more available media. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., digital video discs (DVDs)), or semiconductor media (e.g., solid-state drives (SSDs)).

[0080] This application also provides a computer-readable storage medium for storing the methods or algorithms provided in the above embodiments. Examples include random access memory (RAM), flash memory, read-only memory (ROM), EPROM, non-volatile read-only memory (EEPROM), registers, hard disks, removable disks, or any other form of storage medium in the art.

[0081] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments of this disclosure can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this disclosure.

[0082] In the several embodiments provided in this disclosure, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0083] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0084] In addition, the functional units in the various embodiments of this disclosure can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0085] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A black-start method for a power conversion system, characterized in that, The power conversion system includes at least two power converters, with the AC side of each of the at least two power converters connected in parallel. Each power converter includes a controller. The method includes: The controller is used to acquire the detection result of the power converter, and control the power converter to execute the corresponding black start process according to the detection result; The detection result is used to indicate whether there is voltage on the AC side of the power converter, and the black start process corresponding to the power converter includes the black start process corresponding to the host or the black start process corresponding to the slave.

2. The method according to claim 1, characterized in that, The method further includes: If the detection result indicates that there is voltage on the AC side of the power converter, the controller is used to control the power converter to execute the black start process corresponding to the slave device based on the detection result; If the detection result indicates that there is no voltage on the AC side of the power converter and the startup time of the power converter has arrived, the controller is used to control the power converter to execute the black startup process corresponding to the host according to the detection result.

3. The method according to claim 2, characterized in that, The method further includes: The controller is used to determine the start-up time of the power converter based on the receiving time of the black start signal and the preset address parameters. The value of the address parameter is used to indicate the startup sequence of the power converter.

4. The method according to claim 3, characterized in that, The address parameter takes the value of any positive integer from 1 to N, where N represents the number of power converters.

5. The method according to claim 3 or 4, characterized in that, The method further includes: If the power converter executes the black boot process corresponding to the host, the controller updates the value of the address parameter so that the power converter is the first to be started in the next black boot process.

6. The method according to claim 1, characterized in that, The method further includes: If the power converter executes the black start process corresponding to the host, the controller reports the fault information of at least one power converter preceding the power converter, and the fault information is used to indicate that at least one power converter has a fault.

7. A power conversion system, characterized in that, The power conversion system includes at least two power converters, and the power conversion system includes: The control module is used to acquire the detection results of the power converter and, based on the detection results, control the power converter to execute the corresponding black start process. The detection result is used to indicate whether there is voltage on the AC side of the power converter, and the black start process corresponding to the power converter includes the black start process corresponding to the host or the black start process corresponding to the slave.

8. The power conversion system according to claim 7, characterized in that, The power conversion system further includes: If the detection result indicates that there is voltage on the AC side of the power converter, the control module is used to control the power converter to execute the black start process corresponding to the slave device according to the detection result; If the detection result indicates that there is no voltage on the AC side of the power converter and the startup time of the power converter has arrived, then the control module is used to control the power converter to execute the black startup process corresponding to the host according to the detection result.

9. The power conversion system according to claim 8, characterized in that, The control module is used to determine the start-up time of the power converter based on the receiving time of the black start signal and the preset address parameters. The value of the address parameter is used to indicate the startup sequence of the power converter.

10. The power conversion system according to claim 9, characterized in that, The address parameter takes the value of any positive integer from 1 to N, where N represents the number of power converters.

11. The power conversion system according to claim 9 or 10, characterized in that, The power conversion system further includes: An update module is used to update the value of the address parameter if the power converter executes the black boot process corresponding to the host, so that the power converter is the first to be started in the next black boot process.

12. The power conversion system according to claim 7, characterized in that, The power conversion system further includes: The reporting module is used to report fault information of at least one power converter preceding the power converter if the power converter executes the black start process corresponding to the host. The fault information is used to indicate that the at least one power converter has a fault.

13. A power conversion system, characterized in that, The power conversion system includes: At least two power converters, each of the at least two power converters being used to perform the method as described in any one of claims 1 to 6.

14. A control device, characterized in that, It includes a processor and a memory, the memory being used to store programs, instructions, or code, and the processor being used to execute the programs, instructions, or code in the memory to perform the method executed by the control device as described in any one of claims 1 to 6.

15. A computer-readable storage medium, characterized in that, The device contains a computer program that is loaded by a processor to perform the method as described in any one of claims 1 to 6.

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