Grid-connected operation control method and device of converter, power system and electronic equipment

Abstract

The invention is suitable for the technical field of converter grid-connected operation, and provides a converter grid-connected operation control method and device, an electric power system and electronic equipment, the method is applied to main control equipment in the electric power system, the electric power system comprises the main control equipment and a plurality of converters, and the converters are connected in series through network cables. The grid-connected operation control method comprises the following steps: sending a response information acquisition instruction to a plurality of converters which are connected in series through a first converter; receiving response information fed back by each converter, configuring the first converter feeding back the response information as a main converter, and configuring the rest converters as slave converters; and controlling the main converter to output a synchronous alternating current, transmitting a synchronous signal to the slave converter through the signal side connecting line, and controlling the slave converter to output the synchronous alternating current according to the synchronous signal so as to perform grid-connected operation. According to the scheme, the precision and the stability of grid-connected operation can be improved through setting of the master converter and the slave converter and the synchronizing signal of the signal side.

Description

Technical Field

[0001] The present application belongs to the technical field of grid-connected operation of converters, and in particular, relates to a grid-connected operation control method, device, power system and electronic equipment of a converter. Background Art

[0002] At present, with the high proportion of new energy sources connected to the power system, the stability of the grid-connected converter faces huge challenges. In the relevant technology, the grid-connected mode of the converter is different based on the different control modes of the converter. For example, when the converter control mode is the grid-following type, the grid-connected converter is connected to the grid so that the output power can be supplied to the grid. In the field of renewable energy, the output power of renewable energy equipment is adjusted to the output power with the same frequency and phase as the grid through the converter and then injected into the grid to meet the power demand; when the converter control mode is the grid-building type, there is no grid system, and it is necessary to build a grid based on renewable energy or batteries and multiple converters. The main converter generates AC power by itself, so that the slave machine can be synchronized with the AC power and then connected to the grid built by itself.

[0003] During the grid connection process, it is critical to ensure that the AC power output by the converter is synchronized with the phase of the grid or that the AC power output by each converter is synchronized with each other. However, the existing phase synchronization methods have a slow response speed to grid faults or interference, which may cause phase deviation and unstable operation. In addition, for large-scale grid-connected systems, the accuracy and stability of phase synchronization are also challenges, resulting in the inability of the converter to operate normally. Summary of the invention

[0004] The embodiments of the present application provide a method, device, power system and electronic equipment for controlling the grid-connected operation of a converter, which can improve the accuracy and stability of the grid-connected operation of the converter.

[0005] A first aspect of an embodiment of the present application provides a grid-connected operation control method of a converter, which is applied to a main control device in a power system, wherein the power system includes a main control device and a plurality of converters, and the plurality of converters are serially connected via a network cable; the grid-connected operation control method includes:

[0006] Sending a response information acquisition instruction to a plurality of serially connected converters through a first converter, wherein the first converter refers to a converter connected to a main control device;

[0007] Receive response information fed back by each converter, and configure the converter that first feeds back the response information as a master converter, and configure the remaining converters as slave converters;

[0008] The master converter is controlled to output synchronous AC power synchronized with the power grid, and the synchronization signal is transmitted to the slave converter through the signal side connection line, and the slave converter is controlled to output synchronous AC power synchronized with the power grid according to the synchronization signal, so as to control multiple converters to operate in parallel with the power grid.

[0009] Optionally, the grid-connected operation control method further includes:

[0010] Numbering the multiple converters, and sending preset numbering instructions to the multiple converters so that each converter determines a corresponding preset number;

[0011] Based on a target number, sending a first target data acquisition instruction to a plurality of converters via a first converter;

[0012] The first target data fed back by the target converter via a plurality of cascaded upper converters is received, the target converter is a converter numbered as a target number, and the first target data acquisition instruction includes the target number.

[0013] Optionally, after the plurality of converters are numbered and preset numbering instructions are sent to the plurality of converters so that each converter determines a corresponding preset number, the method further includes:

[0014] Based on at least two target numbers, sending a second target data acquisition instruction to the plurality of converters via the first converter;

[0015] A plurality of target data fed back by at least two target converters respectively via a plurality of cascaded upper converters are received, and the second target acquisition instruction includes at least two target numbers.

[0016] Optionally, receiving target data fed back by the target converter via a plurality of cascaded upper converters includes:

[0017] Control multiple converters to parse the target data acquisition instruction, and compare the obtained target number with the preset number corresponding to the same;

[0018] If the target number is the same as the preset number corresponding to itself, the target converter is controlled to feed back the target data to the main control device based on the target data acquisition instruction.

[0019] Optionally, each converter includes a power board, which is used to adjust the input electrical data of the converter and output synchronous alternating current. The input electrical data includes at least input voltage and input current. The target data includes at least the output frequency, output phase, output voltage, output current and operating temperature of the target converter. The target converter obtains the target data by sampling the synchronous alternating current and operating temperature and feeds it back to the main control device.

[0020] Optionally, each converter is configured with a programmable processor, and each programmable processor is serially connected via a network cable; sending a response information acquisition instruction to the serially connected multiple converters via the first converter includes:

[0021] Sending a response information acquisition instruction to a plurality of converters connected in series through a first programmable processor, wherein the first programmable processor refers to a programmable processor configured in the first converter;

[0022] Receiving response information fed back by each converter, and configuring the converter that first feeds back the response information as a master converter, and configuring the remaining converters as slave converters, including:

[0023] Receive response information fed back by the programmable processor of each converter, configure the converter that first feeds back the response information as the master converter, and configure the remaining converters as slave converters.

[0024] Optionally, each programmable processor is connected through a network cable via a network chip and a network transformer, the programmable processor is an FPGA, the network chip is a Gigabit network chip or a 100M network chip, and the network transformer is used for communication isolation between each converter.

[0025] Optionally, multiple converters are all connected to the signal side connection line; controlling the master converter to output synchronous AC power, transmitting a synchronization signal to the slave converter through the signal side connection line, and controlling the slave converter to output synchronous AC power according to the synchronization signal, so as to control multiple converters to perform grid-connected operation, including:

[0026] Control the main converter to output synchronous AC power, the output frequency and output phase of the synchronous AC power are the frequency and phase of grid-connected operation respectively;

[0027] Control the main converter to output a synchronous signal with the same frequency and phase as the synchronous AC power to the signal side connecting line;

[0028] Control the slave converter to obtain a synchronous signal by sampling the signal side connection line, so that the slave converter outputs synchronous AC power according to the synchronous signal;

[0029] Based on the synchronous AC power output by multiple converters, multiple converters are controlled to perform grid-connected operation.

[0030] Optionally, each converter includes a first signal board and a second signal board, which are respectively used to output a synchronization signal and a sampling synchronization signal; and the grid-connected operation control method further includes:

[0031] When the converter is configured as a main converter, the first signal board controlling the main converter is connected to the signal side connection line to output a synchronization signal to the signal side connection line;

[0032] When the converter is configured as a slave converter, the second signal board of the slave converter is controlled to be connected to the signal side connection line, so as to obtain a synchronization signal by sampling the signal side connection line.

[0033] A second aspect of an embodiment of the present application provides a grid-connected operation control device of a converter, which is configured with a main control device in a power system, wherein the power system includes a main control device and a plurality of converters, and the plurality of converters are serially connected via a network cable; the grid-connected operation control device includes:

[0034] An instruction sending module, used for sending a response information acquisition instruction to a plurality of serially connected converters through a first converter, wherein the first converter refers to a converter connected to a main control device;

[0035] A master-slave configuration module, used for receiving response information fed back by each converter, and configuring the converter that first feeds back the response information as the master converter, and configuring the remaining converters as slave converters;

[0036] The grid-connected control module is used to control the master converter to output synchronous AC power, and transmit the synchronization signal to the slave converter through the signal side connecting line, and control the slave converter to output synchronous AC power according to the synchronization signal, so as to control multiple converters to operate in grid connection.

[0037] A third aspect of an embodiment of the present application provides a power system, the power system comprising a main control device, a plurality of converters, a grid-side connection line, a signal-side connection line, and a plurality of power input devices;

[0038] A main control device, connected to any converter among the multiple converters, the multiple converters are serially connected via a network cable, and is used to perform the method steps of the first aspect as described above;

[0039] A plurality of converters are respectively connected to the signal side connection lines and are used for phase synchronization according to the synchronous alternating current;

[0040] A plurality of electric energy input devices are connected to a plurality of converters one by one respectively, and are used to provide input electrical data for the converters to output synchronous alternating current.

[0041] The fourth aspect of the embodiments of the present application provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the grid-connected operation control method of the first aspect when executing the computer program.

[0042] A fifth aspect of an embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the grid-connected operation control method of the first aspect is implemented.

[0043] A sixth aspect of the embodiments of the present application provides a computer program product. When the computer program product is run on an electronic device, the electronic device executes the grid-connected operation control method of the first aspect.

[0044] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0045] In an embodiment of the present application, the power system includes a master control device and multiple converters, and the multiple converters are serially connected through a network cable. The master control device can send response information to the multiple converters connected in series through the converter connected thereto to obtain instructions, and determine the master converter and the slave converter according to the time sequence of the response information feedback, and then use the synchronization signal on the signal side to achieve phase synchronization between the master converter and the slave converter, and output the same synchronous AC power to control multiple converters to operate in grid connection. The above scheme improves the configuration accuracy of the master and slave converters through serial communication between multiple converters, and performs phase synchronization through the synchronization signal on the signal side, which reduces the delay of the communication transmission synchronization signal, and can improve the accuracy and stability of the converter grid connection operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present application, 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 any creative work.

[0047] Figure 1 A schematic diagram of the structure of a power system provided in an embodiment of the present application;

[0048] Figure 2 is a structural diagram of a specific example of a power system;

[0049] Figure 3 is a structural schematic diagram of another specific example of a power system;

[0050] Figure 4 It is a flow chart of a method for controlling grid-connected operation of a converter provided in an embodiment of the present application;

[0051] Figure 5 is the operation schematic diagram of the main converter;

[0052] Figure 6 is a schematic diagram of the structure of the main converter;

[0053] Figure 7 This is a schematic diagram of the operation of the inverter;

[0054] Figure 8It is a structural schematic diagram of a grid-connected operation control device of a converter provided in an embodiment of the present application;

[0055] Fig. 9 It is a structural schematic diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0056] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0057] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0058] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0059] As used in the specification and appended claims of this application, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting", depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce [described condition or event] is detected" or "in response to detecting [described condition or event]", depending on the context.

[0060] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0061] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the statements "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways. The terms "including", "comprising", "having" and their variations all mean "including but not limited to", unless otherwise specifically emphasized in other ways.

[0062] At present, with the high proportion of new energy sources connected to the power system, the stability of the grid-connected converter faces huge challenges. In the relevant technology, the grid-connected mode of the converter is different based on the different control modes of the converter. For example, when the converter control mode is the grid-following type, the grid-connected converter is connected to the grid so that the output power can be supplied to the grid. In the field of renewable energy, the output power of renewable energy equipment is adjusted to the output power with the same frequency and phase as the grid through the converter and then injected into the grid to meet the power demand; when the converter control mode is the grid-building type, there is no grid system, and it is necessary to build a grid based on renewable energy or batteries and multiple converters. The main converter generates AC power by itself, so that the slave machine can be synchronized with the AC power and then connected to the grid built by itself.

[0063] During the grid connection process, it is critical to ensure that the AC power output by the converter is synchronized with the phase of the grid or that the AC power output by each converter is synchronized with each other. However, the existing phase synchronization methods have a slow response speed to grid faults or interference, which may cause phase deviation and unstable operation. In addition, for large-scale grid-connected systems, the accuracy and stability of phase synchronization are also challenges, resulting in the inability of the converter to operate normally.

[0064] Based on the above problems, the present application provides a method for controlling the grid-connected operation of a converter. In the embodiment of the present application, the power system includes a master control device and multiple converters. The multiple converters are serially connected through a network cable. The master control device can send response information to the multiple converters connected in series through the converter connected thereto to obtain instructions. According to the time sequence of the response information feedback, the master converter and the slave converter are determined. Then, the phase synchronization is achieved between the master converter and the slave converter through the synchronization signal on the signal side, and the same synchronous alternating current is output to control multiple converters to be grid-connected. The above scheme improves the configuration accuracy of the master and slave converters through serial communication between multiple converters, and performs phase synchronization through the synchronization signal on the signal side, which reduces the delay of the communication transmission synchronization signal, and can improve the accuracy and stability of the grid-connected operation of the converter.

[0065] In order to illustrate the technical solution of the present application, specific embodiments are provided below.

[0066] It should be understood that the size of the serial numbers of the steps in this embodiment does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present application.

[0067] See also Figure 1 , the present application embodiment provides a schematic diagram of the structure of a power system. The power system includes a main control device, multiple converters, a grid-side connection line, a signal-side connection line, and multiple power input devices. The main control device is connected to any converter among the multiple converters, such as Figure 1 As shown, the main control device can be connected to the converter at the head of the queue, and can also be connected to the converter at the end of the queue, which is not limited in this application.

[0068] Among them, multiple inverters are connected in series through a network cable, and their network signals are transmitted serially. Each inverter can receive the complete network signal sent by the main control device. Specifically, the main control device sends a network signal to the inverter connected to it. After receiving the network signal, the inverter connected to the main control device forwards the received network signal to the next level inverter through the network cable, and forwards it in sequence, so that each inverter can receive the complete network signal sent by the main control device.

[0069] Among them, each converter is connected to the corresponding power input device respectively, and is used to obtain electrical data input by the power input device to convert and process the input electrical data to obtain alternating current that can be connected to the grid. Its electrical data at least includes input voltage and input current.

[0070] Each converter is also connected to the signal side connection line, and can be phase synchronized according to the synchronous AC power. For example, if one converter generates a synchronization signal according to the synchronous AC power and sends it to the signal side, then other converters can obtain the synchronization signal through the connection with the signal side connection line to generate synchronous AC power corresponding to the synchronization signal and realize grid-connected operation.

[0071] In order to improve the accuracy and stability of the grid-connected operation of the converter, first, the main converter and the slave converter among the multiple converters can be configured through the main control device. Specifically, the main control device can send a response information acquisition instruction to the multiple converters connected in series through the network cable between the converters connected to it. After receiving the response information acquisition instruction, the multiple converters will feedback the response information to the main control device. Therefore, according to the time of the feedback response information, the converter that first feedbacks the response information can be configured as the main converter, and the remaining converters can be configured as slave converters. Secondly, the main control device can control the main converter to output synchronous alternating current for grid-connected operation, and at the same time control the main converter to output a synchronization signal to the signal side according to the synchronous alternating current, wherein the frequency and phase of the synchronization signal are the same as the frequency and phase of the synchronous alternating current. When the synchronization signal can be detected on the connection line on the signal side, the slave converter can sample the signal through the connection with the signal side connection line, obtain the synchronization signal, and then output the same synchronous alternating current as the main converter according to the synchronization signal, and then perform grid-connected operation with the main converter to realize the grid-connected operation control of the converter.

[0072] In an embodiment of the present application, the master control device can configure the master-slave converter by sending response information to obtain instructions, and complete phase synchronization between the master and slave converters according to the synchronization signal on the signal side, thereby performing grid-connected operation. The grid-connected operation control method improves the accuracy and stability of the converter's grid-connected operation.

[0073] In one possible implementation, each converter may be composed of a power board, a control board, and a signal board, wherein the control board is used to receive response information acquisition instructions from the main control device and provide feedback, and may also send a synchronization signal to the signal side, or process the sampled synchronization signal, and output a modulated signal to the power board after processing; the power board is used to output synchronous alternating current, specifically, the power board may convert the electrical data input by the power input device based on the modulated signal sent by the control board, so as to convert it into synchronous alternating current and then output it to the grid side; and the signal board has different functions depending on the direction of signal transmission.

[0074] For example, Figure 2 The structural diagram of a specific example of the power system shown in the figure. The control of the grid-connected operation of the converter can be realized by: the main control device sends a response information acquisition instruction to the control boards of multiple converters through the cascade of network signals, and the converter that feedbacks the fastest response information is used as the master converter, and the remaining converters are configured as slave converters, for example Figure 2As shown in , the converter corresponding to the control board connected to the main control device through the network cable is used as the main converter, and the rest are slave converters. Among them, the direction of the signal board in the main converter is pointing to the signal side connection line, indicating that the signal board transmits signals to the signal side connection line; and the direction of the signal board in the slave converter is pointing to the control board, indicating that the signal board obtains the signal from the signal side connection line and transmits it to the control board.

[0075] The specific method of configuring it as the main inverter can be to determine the inverter corresponding to the inverter identifier based on the feedback response information (such as inverter number, inverter interface number and other inverter identifiers), and control the signal transmission direction of the signal board of the inverter from the control board to the signal side connection line, thereby completing the configuration of the main inverter.

[0076] The specific method of configuring it as a slave converter can be to select a slave converter based on the feedback response information, control the transmission direction of the signal board of the slave converter to be transmitted from the signal side connecting line to the control board, and then complete the configuration of the slave converter.

[0077] Specifically, the process of the control board controlling the power board to output synchronous AC power can be: the control board generates a modulation signal and transmits it to the power board according to the frequency and phase that need to be synchronized, and the power board converts the DC power input by PV (photovoltaic) or Bat (battery) according to the modulation signal and can output synchronous AC power. Among them, for the main converter and the slave converter, the method of obtaining the frequency and phase that need to be synchronized is different. For the main converter, in the grid-following control method, the frequency and phase that need to be synchronized can be obtained by measuring the frequency or phase of the grid connection point, while in the grid-forming control method, there is no grid in the system of the present application, and multiple converters need to output AC power to form a grid. At this time, the main converter generates the frequency and phase that need to be synchronized by itself. For the slave converter, whether it is a grid-following type or a grid-forming type, the synchronization signal is sampled from the signal side connection line to obtain the frequency and phase that need to be synchronized.

[0078] Among them, PV and Bat can provide input power to the power board through BMS (Battery Management System), and the charging and discharging status of PV and Bat can be managed by BMS to more accurately control the input power.

[0079] In a possible implementation, the control board may perform information interaction between multiple converters and generate modulation signals to control power devices of the power board based on FPGA (Field Programmable Gate Array).

[0080] It should be understood that in the related art, the processing method for multi-machine grid connection often adopts a communication solution, but the communication has a certain delay, so the phase synchronization of multi-machine parallel connection cannot be truly achieved through this solution. At this time, if a unified synchronization signal (the signal includes the frequency and phase to be synchronized) is generated for phase synchronization, the above-mentioned delay problem will be greatly improved. However, this requires consuming twice the ADC (Analog to digital converter) resources and twice the PWM (Pulse Width Modulation) wave output resources, and the use of FPGA has a good natural advantage in PWM wave output and parallel processing. Therefore, this application selects FPGA as the main controller of the converter.

[0081] For example, Figure 3 FIG. 1 is a schematic diagram showing another specific example of a power system. Figure 3 The control board is shown to include power supply, ADC, FPGA, TF (Transformer, network transformer), PHY (Physical Layer, external signal interface chip), MCU (Microcontroller Unit, micro control unit), FLASH (flash memory chip), SDRAM (Synchronous Dynamic Random Access Memory, synchronous dynamic random access memory), DDR (Double Data Rate, double rate synchronous dynamic random access memory).

[0082] Among them, the power supply is used to power the chips on the entire control board. The main function of ADC is to collect analog signals and convert them into digital signals for use in the control algorithm inside the FPGA, such as converting them into digital signals of the frequency and phase of synchronous AC power. FPGA is used for loop control of the entire system and generation of PWM waves to control the power devices of the power board. SDRAM / DDR is used for data caching, etc. PHY is an external signal interface chip. Depending on the scenario requirements, it can be a Gigabit or 100M chip for information transmission. TF is a network transformer, which is mainly used for communication isolation between devices. MCU is the business processing part of the control board, including program upgrades, system parameter configuration, instruction parsing, etc. FLASH is mainly used to store programs and system configuration parameters for MCU and FPGA.

[0083] exist Figure 3The power board and synchronization signal board are also shown, which mainly include: power switch tube MOS (MOSFET, field effect transistor), IGBT (Insulated Gate Bipolar Transistor), GaN\SiC (gallium nitride\silicon carbide), power inductor and capacitor, drive circuit, low-power triode, MOS tube, capacitor inductor, relay, etc.

[0084] Among them, current and voltage sampling mainly attenuates and isolates high-voltage AC signals, and converts high-voltage signals into low-voltage signals that can be recognized by ADC. For example, the converter-related parameters (such as output frequency, output phase, output voltage, output current, and operating temperature, etc.) collected by the drive circuit are converted into low-voltage signals that can be recognized by ADC through current and voltage sampling, and then transmitted to FPGA, and then transmitted to the main control device by FPGA, so that the main control device can obtain relevant parameter information of the converter. MOS, IGBT, GaN, SiC, and other high-power devices are mainly power switching tubes, which convert signal-level PWM into power level. For example, the PWM signal sent by the control board is converted into power level for identification. Power inductors and capacitors filter the power-level PWM signal generated by the switch tube and finally convert it into AC. Low-power transistors and MOS, C / L (inductor capacitor) are used to generate synchronization signals (such as three-phase AC signals) that are synchronized with the phase of synchronous AC power.

[0085] In the embodiment of the present application, the configuration of each converter is the same. When one of the converters is configured as a master, the relay on the signal side will be connected to the low-power transistor, MOS, and C / L (inductor and capacitor) of the converter to inject the synchronization signal into the connection line on the signal side. When one of the converters is configured as a slave, the relay on the signal side will be connected to the current and voltage sampling to facilitate sampling, perform phase-locked operations, and synchronize the phase with the phase of the synchronous AC power of the master converter.

[0086] In the embodiment of the present application, multiple converters are cascaded through network signals (Gigabit / 100M network) for signal transmission, such as Figure 3 As shown in , the main control device is connected to the TF of the converter control board through a network cable, and then the TF of the control board is connected to the TF of the next-level converter control board through the network cable until all serial connections are completed to transmit serial signals.

[0087] In an embodiment of the present application, a master control device in an electric power system can send response information acquisition instructions to multiple serially connected converters through the converter connected thereto to configure the master converter and the slave converter, thereby improving the configuration accuracy of the master and slave converters. The master converter is then controlled to output synchronous alternating current according to the electrical data input by the electric energy input device, and a synchronization signal is output according to the synchronous alternating current. The slave converter can output synchronous alternating current after sampling the synchronization signal to achieve phase synchronization, so as to control multiple converters to perform grid-connected operation. When the electric power system performs grid-connected operation control, the delay of the communication transmission synchronization signal is reduced, and the accuracy and stability of the converter grid-connected operation can be improved.

[0088] See also Figure 4 , shows a schematic flow chart of a method for controlling grid-connected operation of a converter provided in an embodiment of the present application; wherein the method in this embodiment is applied to Figure 1 The master device shown in . Figure 4 As shown, the grid-connected operation control method may include the following steps:

[0089] Step 401: Send a response information acquisition instruction to a plurality of serially connected converters through a first converter.

[0090] The first converter refers to a converter connected to the main control device. It should be understood that the main control device and the first converter can be connected via a network cable to receive a response information acquisition instruction sent by the main control device or send feedback information to the main control device.

[0091] The response information acquisition instruction is used to acquire the response information of each converter. It should be noted that the response information may include a converter identification, such as a converter number, a converter interface number, etc. According to the corresponding converter identification, the master control device may configure multiple converters.

[0092] In an embodiment of the present application, the main control device can package the response information acquisition instruction and send it to the first inverter. Since multiple inverters are connected in series, the response information acquisition instruction sent to the first inverter can be transmitted step by step from the first inverter to the next level inverter until each inverter receives the response information acquisition instruction.

[0093] In a possible implementation, the grid-connected operation control method further includes:

[0094] Numbering the multiple converters, and sending preset numbering instructions to the multiple converters so that each converter determines a corresponding preset number;

[0095] Based on a target number, sending a first target data acquisition instruction to a plurality of converters via a first converter;

[0096] The first target data fed back by the target converter via a plurality of cascaded upper converters is received.

[0097] The target converter refers to a converter numbered as a target number, and the first target data acquisition instruction includes the target number.

[0098] In an embodiment of the present application, the master control device can send a preset number instruction to multiple converters so that each converter can determine its corresponding preset number. Specifically, the master control device can determine the preset number range to be assigned to ensure that each converter can obtain a unique preset number, and then send a preset number instruction to the first converter to specify the first preset number. After receiving the instruction, the first converter can determine its own preset number based on its own converter identification. The preset number instruction includes the converter identification and the corresponding preset number. Then the first converter continues to send the preset number instruction to the subordinate converter, and the subordinate converter can determine its own preset number based on its own converter identification, and transmit the preset number instruction downward in sequence until all converters have received and processed the preset number instruction and determined the corresponding preset number.

[0099] It should be noted that in a serial connection, the preset numbered instructions are transmitted to each converter one by one, so there will be a delay in the time it takes for each converter to receive the instructions. In actual operation, it may be necessary to wait for a while to ensure that each converter has received and processed the instructions.

[0100] In addition, for serial connections, the transmission rate and communication protocol limitations must also be considered. Ensure that the serial connection between the master control device and each converter can support reliable data transmission and correct processing.

[0101] In an embodiment of the present application, if you want to obtain relevant parameters of a target converter during operation, you can send a first target data acquisition instruction to multiple converters based on the target number corresponding to the target converter. The first target data acquisition instruction includes the target number and the name of the operating parameter to be obtained. Due to the serial connection between the converters, each converter can receive the first target data acquisition instruction. The converter that receives the first target data acquisition instruction can determine whether to feedback its own operating parameter information by comparing its own number and the target number. Therefore, after sending the first target acquisition instruction, the master control device can receive the first target data fed back by the target converter via multiple cascaded upper converters.

[0102] For example, if you want to obtain relevant parameters of inverter No. 5 during operation, you can send a first target data acquisition instruction including target number 5 to multiple inverters. Each inverter compares its own number with 5, and finally receives the first target data fed back by inverter No. 5 via inverters No. 4, No. 3, No. 2, and No. 1. The first target data is the relevant parameters of inverter No. 5 during operation.

[0103] In a possible implementation, after the plurality of converters are numbered and preset numbering instructions are sent to the plurality of converters so that each converter determines a corresponding preset number, the method further includes:

[0104] Based on at least two target numbers, sending a second target data acquisition instruction to the plurality of converters via the first converter;

[0105] A plurality of target data fed back by at least two target converters respectively via a plurality of cascaded upper converters are received, and the second target acquisition instruction includes at least two target numbers.

[0106] In an embodiment of the present application, if you want to obtain relevant parameters of multiple target converters during operation, you can send a second target data acquisition instruction to multiple converters based on multiple target numbers corresponding to the multiple target converters. The second target data acquisition instruction includes multiple target numbers and the names of the operating parameters that need to be obtained. Due to the serial connection between the converters, each converter can receive the second target data acquisition instruction. The converter that receives the second target data acquisition instruction can determine whether to feedback its own operating parameter information by comparing its own number and the target number. Therefore, after sending the second target acquisition instruction, the master control device can receive multiple target data fed back by multiple target converters via multiple cascaded upper converters.

[0107] Exemplarily, if one wants to obtain relevant parameters of inverters No. 5 and No. 6 during operation, a second target data acquisition instruction including target number 5 and target number 6 can be sent to multiple inverters. Each inverter compares its own number with 5 and 6, and finally receives two sets of target data fed back by inverters No. 5 and No. 6 via inverters No. 4, No. 3, No. 2, and No. 1, which are respectively the relevant parameters of inverter No. 5 during operation and the relevant parameters of inverter No. 6 during operation.

[0108] In a possible implementation, for the above two methods of acquiring target data, receiving target data fed back by a target converter via a plurality of cascaded upper converters may specifically include:

[0109] Control multiple converters to parse the target data acquisition instruction, and compare the obtained target number with the preset number corresponding to the same;

[0110] If the target number is the same as the preset number corresponding to itself, the target converter is controlled to feed back the target data to the main control device based on the target data acquisition instruction.

[0111] The target data includes at least the output frequency, output phase, output voltage, output current and operating temperature of the target converter. The target converter obtains the target data by sampling the synchronous alternating current and the operating temperature and feeds it back to the main control device.

[0112] It should be understood that the synchronous AC power can be obtained by outputting a main converter among multiple converters, and the specific configuration of the main converter can be obtained by the following steps.

[0113] Step 402: Receive response information fed back by each converter, and configure the converter that first feeds back the response information as the master converter, and configure the remaining converters as slave converters.

[0114] In an embodiment of the present application, a specific configuration scheme may be: the main control device sends a response information acquisition instruction to each converter and waits for the converter's response, and then receives the response information of each converter in turn in the serial connection. For example, the response information of each converter may be read through a serial communication protocol, and the response information includes a converter identification and a converter interface number. The converter corresponding to the first response information received is determined as the main converter, and the remaining converters are determined as slave converters.

[0115] In a possible implementation, the response information further includes the serial number of the converter, and the converter corresponding to the first converter serial number received may be determined as the master converter, and the remaining converters may be determined as slave converters.

[0116] Exemplarily, the main control device configures the main converter. First, the signal board with the output signal direction from the control board to the signal side can be connected to the signal side to configure the converter as the main converter, for example Figure 5 As shown in the operation diagram of the main converter, the output signal direction is from the control board to the signal side. The signal board (i.e., the signal board on the left) is connected to the signal side. Connecting the signal board to the signal side indicates that the converter is configured as the main converter.

[0117] For example, Figure 6 The structural schematic diagram of the main converter is shown, in which FPGA is the main controller of the control board. The main control device can control the low-power transistor / MOS and inductor and capacitor in the synchronous signal board through FPGA to connect with the switch on the signal side to configure the converter as the main converter.

[0118] Exemplarily, the master control device configures the slave converter. First, the signal board with the output signal direction from the signal side to the control board can be connected to the signal side to configure the converter as a slave converter, for example Figure 7 As shown in the operation diagram of the slave converter, the signal board (i.e., the signal board on the right) whose output signal direction is from the signal side to the control board is connected to the signal side. Connecting the signal board to the signal side indicates that the converter is configured as a slave converter.

[0119] For example, in Figure 6 In the structural diagram of the main converter shown, the structures of the various parts of the slave converter are the same as those of the main converter. When configured as a slave converter, the main control device can control the current and voltage sampling in the synchronous signal board through FPGA and connect the switch on the signal side, thereby configuring the converter as a slave converter.

[0120] In a possible implementation, each converter is configured with a programmable processor, and each programmable processor is serially connected via a network cable; sending a response information acquisition instruction to a plurality of converters connected in series via a first converter includes:

[0121] Sending a response information acquisition instruction to a plurality of converters connected in series through a first programmable processor;

[0122] Correspondingly, receiving the response information fed back by each converter, and configuring the converter that first feeds back the response information as the master converter, and configuring the remaining converters as slave converters, includes:

[0123] Receive response information fed back by the programmable processor of each converter, configure the converter that first feeds back the response information as the master converter, and configure the remaining converters as slave converters.

[0124] The first programmable processor refers to a programmable processor configured in the first converter, that is, Figure 6 The FPGA of the first converter is shown.

[0125] In the embodiment of the present application, FPGA is a programmable hardware that can be flexibly configured and reprogrammed according to the needs of specific applications. This makes FPGA have advantages in applications that need to be frequently modified, updated or adapted to different algorithms or protocols. Compared with DSP processors, FPGA has shorter design and debugging time. It also has the ability of parallel computing and can perform multiple operations or tasks at the same time. For example, it can output multiple PWM modulated wave signals at the same time, and it has a large number of logic units (Look-Up Tables) and storage units (memory) inside, which can process multiple data streams in parallel, execute multiple instructions or run multiple tasks, thereby achieving high-performance parallel computing.

[0126] Therefore, in the implementation of the present application, a response information acquisition instruction can be sent by a first programmable processor to multiple serially connected converters, response information fed back by the programmable processors of each converter can be received, and the first converter that feeds back the response information can be configured as a master converter, and the remaining converters can be configured as slave converters.

[0127] In a possible implementation, each programmable processor is connected through a network cable via a network chip and a network transformer. The programmable processor is an FPGA, the network chip is a Gigabit network chip or a 100M network chip, and the network transformer is used for communication isolation between each converter.

[0128] Step 403, control the master converter to output synchronous AC power, and transmit a synchronization signal to the slave converter through the signal side connection line, control the slave converter to output synchronous AC power according to the synchronization signal, so as to control multiple converters to perform grid-connected operation.

[0129] The synchronous AC power output by the main converter may be synchronous AC power generated in synchronization with the grid by measuring the grid frequency and grid phase at the grid connection point, or may be synchronous AC power generated autonomously without relying on the grid.

[0130] In an embodiment of the present application, a synchronization signal may be generated based on the frequency and phase of the synchronous alternating current. The synchronization signal may be a three-phase sinusoidal signal. The frequency and phase of the three-phase sinusoidal signal are the same as the frequency and phase of the synchronous alternating current. The frequency and phase information may be transmitted to the slave inverter through the signal side connecting line, so that the slave inverter outputs synchronous alternating current according to the synchronization signal and controls multiple inverters for grid-connected operation.

[0131] In a possible implementation, multiple converters are connected to a signal-side connection line; controlling a master converter to output synchronous AC power, transmitting a synchronization signal to a slave converter through the signal-side connection line, and controlling the slave converter to output synchronous AC power according to the synchronization signal, so as to control multiple converters to perform grid-connected operation, including:

[0132] Control the main converter to output synchronous AC power, the output frequency and output phase of the synchronous AC power are the frequency and phase of grid-connected operation respectively;

[0133] Control the main converter to output a synchronous signal with the same frequency and phase as the synchronous AC power to the signal side connecting line;

[0134] Control the slave converter to obtain a synchronous signal by sampling the signal side connection line, so that the slave converter outputs synchronous AC power according to the synchronous signal;

[0135] Based on the synchronous AC power output by multiple converters, multiple converters are controlled to perform grid-connected operation.

[0136] In an embodiment of the present application, in the grid-following control mode of the converter, the frequency and phase of the grid-connected operation refer to the frequency and phase of the power grid; in the grid-building control mode of the converter, the frequency and behavior of the grid-connected operation refer to the frequency and phase autonomously generated by the main converter.

[0137] Exemplarily, the main inverter can output a three-phase sinusoidal signal to the signal side connection line according to the frequency and phase of the synchronous AC power to transmit the frequency and phase information of the synchronous AC power. The slave inverter can obtain the frequency and phase information of the synchronous AC power according to the sampled synchronization signal. The frequency and phase information of the synchronous AC power can be obtained to generate synchronous AC power. Multiple inverters all output the same synchronous AC power, so that they can be connected to the grid for operation.

[0138] In an embodiment of the present application, the power system includes a master control device and multiple converters, and the multiple converters are serially connected through a network cable. The master control device can send response information to the multiple converters connected in series through the converter connected thereto to obtain instructions, and determine the master converter and the slave converter according to the time sequence of the response information feedback, and then use the synchronization signal on the signal side to achieve phase synchronization between the master converter and the slave converter, and output the same synchronous AC power to control multiple converters to operate in grid connection. The above scheme improves the configuration accuracy of the master and slave converters through serial communication between multiple converters, and performs phase synchronization through the synchronization signal on the signal side, which reduces the delay of the communication transmission synchronization signal, and can improve the accuracy and stability of the converter grid connection operation.

[0139] See also Figure 8 , shows a schematic diagram of the structure of a grid-connected operation control device of a converter provided in an embodiment of the present application. For ease of description, only the parts related to the embodiment of the present application are shown.

[0140] The grid-connected operation control device 8 may specifically include the following modules:

[0141] The instruction sending module 801 is used to send a response information acquisition instruction to multiple serially connected converters through a first converter, wherein the first converter refers to a converter connected to a main control device;

[0142] A master-slave configuration module 802 is used to receive response information fed back by each converter, and configure the converter that first feeds back the response information as the master converter, and configure the remaining converters as slave converters;

[0143] The grid-connected control module 803 is used to control the master converter to output synchronous AC power, and transmit synchronization signals to the slave converters through the signal side connection lines, and control the slave converters to output synchronous AC power according to the synchronization signals, so as to control multiple converters to perform grid-connected operation.

[0144] In the embodiment of the present application, the grid-connected operation control device 8 may further include the following modules:

[0145] A numbering module, used for numbering the multiple converters, and sending preset numbering instructions to the multiple converters so that each converter determines a corresponding preset number;

[0146] A first acquisition instruction sending module, used for sending a first target data acquisition instruction to a plurality of converters via a first converter based on a target number;

[0147] The first data receiving module is used to receive first target data fed back by a target converter via a plurality of cascaded upper converters, the target converter refers to a converter numbered as a target number, and the first target data acquisition instruction includes the target number.

[0148] In the embodiment of the present application, the grid-connected operation control device 8 may further include the following modules:

[0149] A second acquisition instruction sending module, used for sending a second target data acquisition instruction to a plurality of converters via the first converter based on at least two target numbers;

[0150] The second data receiving module is used to receive a plurality of target data fed back by at least two target converters respectively via a plurality of cascaded upper converters, and the second target acquisition instruction includes at least two target numbers.

[0151] In the embodiment of the present application, the first data receiving module and the second data receiving module can be specifically used for:

[0152] Control multiple converters to parse the target data acquisition instruction, and compare the obtained target number with the preset number corresponding to the same;

[0153] If the target number is the same as the preset number corresponding to itself, the target converter is controlled to feed back the target data to the main control device based on the target data acquisition instruction.

[0154] In an embodiment of the present application, each converter in the power system includes a power board, which is used to adjust the input electrical data of the converter and output synchronous alternating current. The input electrical data includes at least input voltage and input current. The target data includes at least the output frequency, output phase, output voltage, output current and operating temperature of the target converter. The target converter obtains the target data by sampling the synchronous alternating current and operating temperature and feeds it back to the main control device.

[0155] In the embodiment of the present application, each converter is configured with a programmable processor, and each programmable processor is serially connected via a network cable; the instruction sending module 801 may specifically include the following submodules:

[0156] A processor execution module, configured to send a response information acquisition instruction to a plurality of converters connected in series through a first programmable processor, wherein the first programmable processor refers to a programmable processor configured in the first converter;

[0157] Correspondingly, the master-slave configuration module 802 may specifically include the following submodules:

[0158] The response receiving submodule is used to receive the response information fed back by the programmable processor of each converter, and configure the converter that first feeds back the response information as the master converter, and configure the remaining converters as slave converters.

[0159] In an embodiment of the present application, each programmable processor is connected through a network cable via a network chip and a network transformer. The programmable processor is an FPGA, the network chip is a Gigabit network chip or a 100M network chip, and the network transformer is used for communication isolation between each converter.

[0160] In the embodiment of the present application, multiple converters are connected to the connection line on the signal side; the grid-connected control module 803 may specifically include the following submodules:

[0161] The first control submodule is used to control the main converter to output synchronous AC power, wherein the output frequency and output phase of the synchronous AC power are the frequency and phase of the grid-connected operation respectively;

[0162] The second control submodule is used to control the main converter to output a synchronous signal with the same frequency and phase as the synchronous AC power to the signal side connecting line;

[0163] The third control submodule is used to control the slave converter to sample the signal side connection line to obtain a synchronization signal, so that the slave converter outputs a synchronous AC power according to the synchronization signal;

[0164] The fourth control submodule is used to control the multiple converters to perform grid-connected operation based on the synchronous alternating current output by the multiple converters.

[0165] In the embodiment of the present application, each converter includes a first signal board and a second signal board, which are respectively used to output a synchronization signal and a sampling synchronization signal; the grid-connected operation control device 8 may further include the following modules:

[0166] A synchronization signal output submodule, used for controlling the first signal board of the main converter to be connected to the signal side connection line when the converter is configured as a main converter, so as to output a synchronization signal to the signal side connection line;

[0167] The synchronous signal sampling submodule is used to control the second signal board of the slave converter to be connected to the signal side connection line when the converter is configured as a slave converter, so as to obtain a synchronous signal by sampling from the signal side connection line.

[0168] The grid-connected operation control device 8 provided in the embodiment of the present application can be applied in the aforementioned grid-connected operation control method embodiment. For details, please refer to the description of the aforementioned method embodiment, which will not be repeated here.

[0169] Fig. 9 is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application, such as Fig. 9 As shown, the electronic device 900 of this embodiment includes: at least one processor 910 ( Fig. 9 Only one is shown), a memory 920, and a computer program 921 stored in the memory 920 and executable on the at least one processor 910, wherein the processor 910 implements the steps in the above-mentioned embodiment of the grid-connected operation control method of the converter when executing the computer program 921.

[0170] The electronic device 900 may be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The electronic device may include, but is not limited to, a processor 910 and a memory 920. Those skilled in the art will appreciate that Fig. 9 This is merely an example of the electronic device 900 and does not constitute a limitation on the electronic device 900 . The electronic device 900 may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, it may also include input and output devices, network access devices, etc.

[0171] The processor 910 may be a central processing unit (CPU). In the embodiment of the present application, the processor 910 may refer to a control board in the above-mentioned converter configuration. The processor 910 may also be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0172] In some embodiments, the memory 920 may be an internal storage unit of the electronic device 900, such as a hard disk or memory of the electronic device 900. In other embodiments, the memory 920 may also be an external storage device of the electronic device 900, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the electronic device 900. Further, the memory 920 may also include both an internal storage unit of the electronic device 900 and an external storage device. The memory 920 is used to store an operating system, an application program, a boot loader (Boot Loader), data and other programs, such as the program code of the computer program, etc. The memory 920 may also be used to temporarily store data that has been output or is to be output.

[0173] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0174] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0175] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0176] In the embodiments provided in the present application, it should be understood that the disclosed devices / electronic devices and methods can be implemented in other ways. For example, the device / electronic device embodiments described above are merely schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0177] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0178] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0179] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0180] The present application implements all or part of the processes in the above-mentioned embodiment method, and may also be completed through a computer program product. When the computer program product runs on an electronic device, the electronic device can implement the steps in the above-mentioned method embodiments when executing.

[0181] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application is described in detail with reference to the above-mentioned embodiments, a person skilled in the art should understand that the technical solutions described in the above-mentioned embodiments can still be modified, or some of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application.

Claims

1. A method for controlling grid-connected operation of a converter, characterized in that: A main control device applied to an electric power system, wherein the electric power system comprises the main control device and a plurality of converters, wherein the plurality of converters are serially connected via a network cable; The grid-connected operation control method comprises: Sending a response information acquisition instruction to the plurality of converters connected in series through a first converter, wherein the first converter is a converter connected to the main control device; Receiving response information fed back by each of the converters, and configuring the converter that first feeds back the response information as a master converter, and configuring the remaining converters as slave converters; The master converter is controlled to output synchronous AC power, and a synchronization signal is transmitted to the slave converter via a signal side connection line, and the slave converter is controlled to output the synchronous AC power according to the synchronization signal, so as to control the multiple converters to perform grid-connected operation.

2. The grid-connected operation control method according to claim 1, characterized in that: The grid-connected operation control method further includes: Numbering the multiple converters, and sending preset numbering instructions to the multiple converters so that each converter determines a corresponding preset number; Based on a target number, sending a first target data acquisition instruction to the plurality of converters via the first converter; The first target data fed back by the target converter via a plurality of cascaded upper converters is received, wherein the target converter is a converter numbered as the target number, and the first target data acquisition instruction includes the target number.

3. The grid-connected operation control method according to claim 2, characterized in that: After numbering the plurality of converters and sending preset numbering instructions to the plurality of converters so that each converter determines a corresponding preset number, the method further includes: Based on at least two target numbers, sending a second target data acquisition instruction to the plurality of converters via the first converter; A plurality of target data fed back by at least two target converters respectively via a plurality of cascaded upper converters is received, and the second target acquisition instruction includes the at least two target numbers.

4. The grid-connected operation control method according to any one of claims 2 to 3, characterized in that: Receiving target data fed back by a target converter via a plurality of cascaded upper converters, including: Controlling the plurality of converters to parse the target data acquisition instruction, and comparing the obtained target numbers with the preset numbers corresponding to the respective converters; If the target number is the same as the preset number corresponding to itself, the target converter is controlled to feed back the target data to the main control device based on the target data acquisition instruction.

5. The grid-connected operation control method according to claim 4, characterized in that: Each of the converters includes a power board, which is used to adjust the input electrical data of the converter and output the synchronous alternating current. The input electrical data includes at least input voltage and input current. The target data includes at least the output frequency, output phase, output voltage, output current and operating temperature of the target converter. The target converter obtains the target data by sampling the synchronous alternating current and the operating temperature and feeds it back to the main control device.

6. The grid-connected operation control method according to claim 1, characterized in that: Each of the converters is equipped with a programmable processor, and each of the programmable processors is serially connected via a network cable; The step of sending a response information acquisition instruction to the plurality of converters connected in series through the first converter comprises: Sending a response information acquisition instruction to the plurality of converters connected in series through a first programmable processor, wherein the first programmable processor refers to a programmable processor configured in the first converter; The receiving the response information fed back by each of the converters, and configuring the converter that first feeds back the response information as the master converter, and configuring the remaining converters as slave converters, comprises: Receive response information fed back by the programmable processors of the converters, configure the converter that first feeds back the response information as a master converter, and configure the remaining converters as slave converters.

7. The grid-connected operation control method according to claim 6, characterized in that: Each of the programmable processors is connected via a network chip and a network transformer through a network cable. The programmable processor is an FPGA, the network chip is a Gigabit network chip or a 100M network chip, and the network transformer is used for communication isolation between various converters.

8. The grid-connected operation control method according to claim 1, characterized in that: The multiple converters are all connected to the connection line on the signal side; the control of the master converter to output synchronous AC power, and the transmission of a synchronization signal to the slave converter through the signal side connection line, and the control of the slave converter to output the synchronous AC power according to the synchronization signal, so as to control the multiple converters to perform grid-connected operation, including: Controlling the main converter to output the synchronous alternating current, wherein the output frequency and output phase of the synchronous alternating current are respectively the frequency and phase of grid-connected operation; Controlling the main converter to output a synchronous signal having the same frequency and phase as the synchronous alternating current to the signal side connecting line; Controlling the slave converter to obtain the synchronization signal by sampling from the signal side connection line, so that the slave converter outputs the synchronous alternating current according to the synchronization signal; Based on the synchronous alternating current output by the multiple converters, the multiple converters are controlled to perform grid-connected operation.

9. The grid-connected operation control method according to claim 1, characterized in that: Each converter includes a first signal board and a second signal board, which are respectively used to output the synchronization signal and sample the synchronization signal; The grid-connected operation control method further includes: When the converter is configured as the main converter, the first signal board of the main converter is controlled to be connected to the signal side connection line to output the synchronization signal to the signal side connection line; When the converter is configured as the slave converter, the second signal board of the slave converter is controlled to be connected to the signal-side connecting line, so as to obtain the synchronization signal by sampling from the signal-side connecting line.

10. A grid-connected operation control device for a converter, characterized in that: A main control device configured in an electric power system, wherein the electric power system comprises the main control device and a plurality of converters, wherein the plurality of converters are serially connected via a network cable; The grid-connected operation control device comprises: An instruction sending module, used for sending a response information acquisition instruction to the plurality of serially connected converters through a first converter, wherein the first converter refers to a converter connected to the main control device; A master-slave configuration module, used to receive the response information fed back by each of the converters, and configure the converter that first feeds back the response information as the master converter, and configure the remaining converters as slave converters; The grid-connected control module is used to control the master converter to output synchronous AC power, and transmit a synchronization signal to the slave converter through a signal side connection line, and control the slave converter to output the synchronous AC power according to the synchronization signal, so as to control the multiple converters to perform grid-connected operation.

11. A power system, characterized in that: The power system includes a main control device, a plurality of converters, a grid-side connection line, a signal-side connection line, and a plurality of power input devices; The main control device is connected to any one of the multiple converters, and the multiple converters are serially connected via a network cable, and is used to perform the method steps according to any one of claims 1 to 9; The multiple converters are respectively connected to the signal side connection lines and are used to perform phase synchronization according to the synchronous alternating current; The multiple electric energy input devices are connected to the multiple converters one by one, respectively, and are used to provide input electrical data for the converters to output synchronous alternating current.

12. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 9 is implemented.

13. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 9 is implemented.

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