Micro-grid system and synchronization control method

Abstract

The application discloses a micro-grid system and a synchronous control method, and belongs to the technical field of energy. The micro-grid system comprises a first master control device and a plurality of controlled devices, and the time between the clock of the first master control device and the clock of the plurality of controlled devices is consistent. The first master control device is used for generating first control information, and the first control information comprises a control time, the identification of the plurality of controlled devices, the target task of each controlled device in the plurality of controlled devices and the start mode of the controlled device for starting to execute the target task. The first master control device is also used for sending the first control information to the plurality of controlled devices; and the plurality of controlled devices are used for receiving the first control information. The plurality of controlled devices are also used for performing a start operation on the target task corresponding to the controlled device according to the start mode when the control time arrives, so that the synchronous control of the plurality of controlled devices is realized, and the time difference of starting work of the plurality of controlled devices is effectively reduced.

Description

Technical Field

[0001] This application relates to the field of energy technology, and in particular to a microgrid system and a synchronization control method. Background Technology

[0002] Microgrid systems can include thousands of end-side devices (or controlled devices), such as inverters, energy storage converters, and energy storage batteries. To achieve synchronized operation of these devices, they need to execute the same control command synchronously. This is typically done by the master control device broadcasting control information to multiple controlled devices. However, due to network topology and transmission quality issues in microgrid systems, the time it takes for each controlled device to receive the control information from the master control device varies. This results in a time lag in the master control device's startup process, leading to prolonged startup time or startup failure. Summary of the Invention

[0003] This application provides a microgrid system and a synchronous control method to achieve synchronous control of multiple controlled devices, effectively reducing the time difference between the start-up of multiple controlled devices. The technical solution is as follows.

[0004] Firstly, a microgrid system is provided, comprising a first master controller and multiple controlled devices. The clocks of the first master controller and the multiple controlled devices are synchronized. The first master controller generates first control information, which includes a control time, identifiers of the multiple controlled devices, a target task for each controlled device, and a startup mode for the controlled device to execute the target task. The first master controller also sends the first control information to the multiple controlled devices. The multiple controlled devices receive the first control information and, upon the arrival of the control time, execute a startup operation on the target task corresponding to each controlled device according to the startup mode. By synchronizing the time between the first master controller and the multiple controlled devices, the information sent by the first master controller to the multiple controlled devices carries the control time, the target task for each controlled device, and the startup mode for the controlled device to execute the target task. Thus, upon the arrival of the control time, the startup operation on the target task corresponding to each controlled device is executed according to the startup mode, achieving synchronous control of the multiple controlled devices and effectively reducing the time difference in startup between the multiple controlled devices.

[0005] In one possible implementation, the first master control device is also used to monitor the electrical signal on the power cable. When the electrical signal exceeds a threshold, it updates the first control information to obtain updated first control information, which includes an updated control time, an updated target task, and an updated startup mode. The first master control device is also used to send the updated first control information to multiple controlled devices. The multiple controlled devices are also used to receive the updated first control information and, when the updated control time arrives, execute a startup operation on the updated target task corresponding to the controlled device according to the updated startup mode. During the synchronous control of multiple controlled devices, the first master control device can also monitor the electrical signal on the power cable in real time. When the electrical signal exceeds a threshold, it updates the first control information to obtain updated first control information, thereby re-controlling the multiple controlled devices to achieve synchronous control. This allows for real-time adjustments based on real-time changes, offering greater flexibility and practicality.

[0006] In one possible implementation, the first control information is used to control the fault waveform recording; the first master control device is also used to monitor the electrical signal on the power cable, and generate the first control information when the electrical signal exceeds a threshold; or, the first master control device is also used to receive a request for fault waveform recording reported by at least one of the multiple controlled devices, and generate the first control information according to the request. For the fault waveform recording scenario, the first master control device can trigger the generation of the first control information, i.e., fault waveform recording control information, by monitoring abnormal fluctuations in the electrical signal on the power cable; or, the first master control device can trigger the generation of the first control information, i.e., fault waveform recording control information, by receiving a request reported by at least one of the lower-level controlled devices.

[0007] In one possible implementation, the microgrid system further includes a second master control device, which is a superior control device to the first master control device. The first control information is used to control fault recording. The first master control device also receives second control information sent by the second master control device, which triggers the first master control device to generate the first control information. The second control information is generated by the second master control device monitoring electrical signals on the power cables and when the electrical signal exceeds a threshold; alternatively, the second control information is generated by the second master control device receiving a request for fault recording from the first master control device and generating it accordingly. For the fault recording scenario, the first master control device can also have a superior control device, i.e., the second master control device. In this case, the second master control device can trigger the first master control device to generate the first control information by sending the second control information to the first master control device. The second control information is triggered by the second master control device monitoring abnormal fluctuations in electrical signals on the power cables; alternatively, the second control information is triggered by the second master control device receiving a request from a subordinate first master control device.

[0008] In one possible implementation, the microgrid system further includes a third master control device, which is an upstream control device of the first master control device. The first control information is used to control black start. The first master control device also receives third control information sent by the third master control device, which triggers the first master control device to generate the first control information. For the black start scenario, the first master control device can trigger the generation of the first control information, i.e., the black start control information, by receiving control information sent by the upstream control device.

[0009] In one possible implementation, the microgrid system is a photovoltaic system, and the microgrid system also includes a box-type transformer, with multiple controlled devices connected to the same conductor of the box-type transformer; the first master control device is further configured to collect at least one of the following for each of the multiple controlled devices: DC input information, weather and sunshine forecast information, rated power, apparent power, or internal power topology model, based on third control information; the first master control device is further configured to determine the output capacity of each of the multiple controlled devices based on at least one of the following: DC input information, weather and sunshine forecast information, rated power, apparent power, or internal power topology model; the first master control device is further configured to determine the control time, the identification of the multiple controlled devices, the target task of each of the multiple controlled devices, and the start-up mode for the controlled devices to start executing the target task, based on the number of devices in the microgrid system, the output capacity of each controlled device, and the load of the box-type transformer, in order to generate first control information.

[0010] For photovoltaic (PV) system scenarios, the first master control device can collect at least one of the following from multiple controlled devices: DC input information, weather and solar radiation forecast information, rated power, apparent power, or internal power topology model. Based on this information, the output capacity of each controlled device is determined. Then, based on the number of devices in the microgrid system, the output capacity of each controlled device, and the load of the box-type transformer, first control information is determined. In this way, the generation of first control information incorporates information from each controlled device in the PV system, allowing for adjustments based on actual conditions, thus increasing flexibility and practicality. Furthermore, by incorporating information from each controlled device in the PV system, a target controlled device can be selected for black start, effectively ensuring that multiple target controlled devices can perform black start simultaneously.

[0011] In one possible implementation, the microgrid system is an energy storage system, and the microgrid system also includes a box-type transformer, with multiple controlled devices connected to the same conductor of the box-type transformer; the first master control device is further configured to collect at least one of the following for each of the multiple controlled devices: voltage, frequency, rated power, droop factor, or state of charge, based on third control information; the first master control device is further configured to determine the output capacity of each of the multiple controlled devices based on at least one of the following: voltage, frequency, rated power, droop factor, or state of charge; the first master control device is further configured to determine the control time, the identification of the multiple controlled devices, the target task of each of the multiple controlled devices, and the start-up mode for the controlled devices to start executing the target task, based on the number of devices in the microgrid system, the output capacity of each controlled device, and the load of the box-type transformer, in order to generate first control information.

[0012] For energy storage system scenarios, the first master control device can collect at least one of the following parameters for each controlled device: voltage, frequency, rated power, droop factor, or state of charge. Based on this information, the output capacity of each controlled device is determined. Then, based on the number of devices in the microgrid system, the output capacity of each controlled device, and the load of the box-type transformer, the first control information is determined. In this way, the generation of the first control information incorporates information from each controlled device in the energy storage system, allowing for adjustments based on actual conditions, thus increasing flexibility and practicality. Furthermore, by incorporating information from each controlled device in the charging system, a target controlled device can be selected for black start, effectively ensuring that multiple target controlled devices can perform black start simultaneously.

[0013] In one possible implementation, in the case of alternating current, the first control information further includes a threshold voltage or threshold current that triggers the controlled device to perform a start-up operation. The first control information also includes the threshold voltage or threshold current that triggers the controlled device to perform the start-up operation. In this way, the synchronous control of multiple controlled devices is not only based on control time but also includes phase synchronization, making the synchronous control of multiple controlled devices more precise and consistent.

[0014] In one possible implementation, a first master control device and multiple controlled devices are networked via power line communication (PLC). The first master control device also sends a first message to the multiple controlled devices, carrying the time difference between the Coordinated Universal Time (UTC) standard time and the network time base (NTB) values ​​of the multiple controlled devices at a first moment. Each of the multiple controlled devices also receives the first message and adjusts its UTC standard time according to the time difference and the NTB value at a second moment. When the first master control device and the multiple controlled devices are networked via PLC, the first master control device sends a message carrying the time difference between the UTC standard time and the NTB values ​​of the multiple controlled devices at a first moment. Upon receiving this message, the multiple controlled devices can adjust their UTC standard time based on the time difference, thus achieving time synchronization.

[0015] Secondly, a synchronization control method is provided, which is applied to a microgrid system. The microgrid system includes a first master control device and multiple controlled devices, and the clocks of the first master control device and the multiple controlled devices are kept in sync. The method includes: the first master control device generating first control information, which includes a control time, identifiers of the multiple controlled devices, a target task of each of the multiple controlled devices, and a startup mode for the controlled devices to start executing the target task; the first master control device sending the first control information to the multiple controlled devices; the multiple controlled devices receiving the first control information; and the multiple controlled devices executing a startup operation on the target task corresponding to the controlled device according to the startup mode when the control time arrives.

[0016] In one possible implementation, the method further includes: a first master control device monitoring electrical signals on a power cable; when the electrical signal exceeds a threshold, updating first control information to obtain updated first control information, the updated first control information including updated control time, updated target task, and updated startup mode; the first master control device sending the updated first control information to multiple controlled devices; the multiple controlled devices receiving the updated first control information, and when the updated control time arrives, performing a startup operation on the updated target task corresponding to the controlled device according to the updated startup mode.

[0017] In one possible implementation, the first control information is used to control the fault recording; the first master control device generates the first control information, including: the first master control device monitors the electrical signal on the power cable, and generates the first control information when the electrical signal is greater than a threshold; or, the first master control device receives a request for fault recording reported by at least one of a plurality of controlled devices, and generates the first control information according to the request.

[0018] In one possible implementation, the microgrid system further includes a second master control device, which is an upstream control device of the first master control device. The first control information is used to control the fault recording. The first master control device receives second control information sent by the second master control device, which is used to trigger the first control device to generate the first control information. The second control information is generated by the second master control device when it monitors the electrical signal on the power cable and the electrical signal is greater than a threshold. Alternatively, the second control information is generated by the second master control device when it receives a request for fault recording reported by the first master control device and generates it according to the request.

[0019] In one possible implementation, the microgrid system further includes a third master control device, which is an upstream control device of the first master control device; the first control information is used to control black start; the first master control device generates the first control information, including: receiving the third control information sent by the third master control device through the first master control device, the third control information being used to trigger the first control device to generate the first control information.

[0020] In one possible implementation, the microgrid system is a photovoltaic system, and the microgrid system also includes a box-type transformer, with multiple controlled devices connected to the same conductor of the box-type transformer. After the first master control device receives the third control information sent by the third master control device, the method further includes: the first master control device collecting at least one of the following for each of the multiple controlled devices: DC input information, weather and sunshine forecast information, rated power, apparent power, or internal power topology model, based on the third control information; the first master control device determining the output capacity of each of the multiple controlled devices based on the DC input information, weather and sunshine forecast information, rated power, apparent power, or internal power topology model; and the first master control device determining the control time, the identifier of the multiple controlled devices, the target task of each of the multiple controlled devices, and the start-up mode for the controlled devices to start executing the target task, based on the number of devices in the microgrid system, the output capacity of each controlled device, and the load of the box-type transformer, to generate the first control information.

[0021] In one possible implementation, the microgrid system is an energy storage system, and the microgrid system also includes a box-type transformer, with multiple controlled devices connected to the same conductor of the box-type transformer. After the first master control device receives the third control information sent by the third master control device, the method further includes: the first master control device collecting at least one of the following for each of the multiple controlled devices: voltage, frequency, rated power, droop factor, or state of charge; the first master control device determining the output capacity of each of the multiple controlled devices based on at least one of the following: voltage, frequency, rated power, droop factor, or state of charge; and the first master control device determining the control time, the identifier of the multiple controlled devices, the target task of each of the multiple controlled devices, and the start-up mode for the controlled devices to start executing the target task, based on the number of devices in the microgrid system, the output capacity of each controlled device, and the load of the box-type transformer, to generate the first control information.

[0022] In one possible implementation, in the case of alternating current, the first control information also includes a threshold voltage or threshold current that triggers the controlled device to perform a start-up operation.

[0023] In one possible implementation, a first master control device and multiple controlled devices are networked via a power line carrier communication PLC; time synchronization between the first master control device and the multiple controlled devices includes: the first master control device sending a first message to the multiple controlled devices, the first message carrying the time difference between Coordinated Universal Time (UTC) and the network time base (NTB) values ​​of the multiple controlled devices at a first moment; each of the multiple controlled devices receiving the first message and adjusting its UTC standard time according to the time difference and the NTB value on the controlled device at a second moment.

[0024] It should be understood that the beneficial effects of the technical solution of the second aspect of this application and the corresponding possible implementation can be found in the above description of the technical effects of the first aspect and its corresponding possible implementation, and will not be repeated here. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of a photovoltaic system provided in related technologies;

[0026] Figure 2 This application provides a schematic diagram of the structure of a microgrid system according to an embodiment of the present application.

[0027] Figure 3 This is a schematic diagram of another microgrid system provided in an embodiment of this application;

[0028] Figure 4 A flowchart illustrating a synchronization control method provided in an embodiment of this application;

[0029] Figure 5 A schematic diagram of a time synchronization process in a synchronization control method provided in this application embodiment;

[0030] Figure 6 A schematic diagram illustrating another time synchronization process in a synchronization control method provided in this application embodiment;

[0031] Figure 7 This is a schematic diagram of the structure of control information provided in an embodiment of this application;

[0032] Figure 8 A flowchart illustrating a synchronization control method provided in an embodiment of this application;

[0033] Figure 9 A flowchart illustrating another synchronization control method provided in an embodiment of this application;

[0034] Figure 10 A flowchart illustrating another synchronization control method provided in an embodiment of this application;

[0035] Figure 11 This is a flowchart illustrating another synchronization control method provided in an embodiment of this application. Detailed Implementation

[0036] The terminology used in the implementation section of this application is for the purpose of explaining specific embodiments of this application only, and is not intended to limit this application.

[0037] A microgrid system can include thousands of end-side devices (or controlled devices), such as inverters, energy storage converters, and energy storage batteries. To enable these devices to operate synchronously, they need to execute the same control command simultaneously. For example, a microgrid system can be a photovoltaic system. Figure 1 This is a structural schematic diagram of a photovoltaic system provided in related technologies, such as... Figure 1 As shown, a photovoltaic system may include multiple photovoltaic modules, multiple inverters, a subarray controller, a main control unit, and a box-type transformer (referred to as a box-type transformer). The main control unit is electrically connected to the subarray controller, which is electrically connected to multiple photovoltaic modules and multiple inverters. All inverters are electrically connected to the box-type transformer. The photovoltaic modules directly absorb sunlight and convert it into electric current. The subarray controller aggregates and processes the current output from the multiple photovoltaic modules. The inverters convert the DC current aggregated by the subarray controller into AC current to match the standard frequency and voltage of the power grid. The box-type transformer steps up or steps down the AC current output from the inverters to adapt to transmission lines of different voltage levels.

[0038] To achieve synchronous operation of multiple inverters, these devices need to execute the same control command simultaneously. The typical approach is as follows: the master controller broadcasts the control command to the sub-array controllers. Upon receiving the command, the sub-array controllers broadcast it to all inverters. All inverters, upon receiving the command, immediately execute the corresponding operation. However, during broadcast communication, due to network topology and transmission quality issues in the photovoltaic system, the time it takes for each inverter to receive the control command from the master controller can vary, sometimes by as much as 10-20ms. This can cause the inverter that starts first to generate reverse current, flowing back to the inverter that starts later, thus prolonging the startup time or causing startup failure.

[0039] To address the aforementioned technical problems, this application provides a microgrid system comprising a first master controller and multiple controlled devices. The clock of the first master controller is synchronized with the clocks of the multiple controlled devices, meaning the first master controller and the multiple controlled devices are time-synchronized. The first master controller generates first control information, which includes a control time, identifiers of the multiple controlled devices, a target task for each controlled device, and a startup mode for the controlled device to execute the target task. The first master controller also sends the first control information to the multiple controlled devices; the multiple controlled devices receive the first control information. The multiple controlled devices further execute a startup operation on the target task corresponding to each controlled device according to the startup mode when the control time arrives. Through time synchronization between the first master controller and the multiple controlled devices, the information sent by the first master controller to the multiple controlled devices carries the control time, the target task for each controlled device, and the startup mode for the controlled device to execute the target task. In this way, when the control time arrives, the target task corresponding to the controlled device is started according to the start mode, so as to realize the synchronous control of multiple controlled devices and effectively reduce the time difference between the start-up of multiple controlled devices.

[0040] The aforementioned first master control device can be a first-level control device, a second-level control device, or even a third-level control device. Therefore, in this embodiment, the first master control device is not specifically limited; it can be a direct control device of the controlled device, such as a second-level control device; or it can be an indirect control device of the controlled device, that is, a superior control device to the direct control device of the controlled device, such as a first-level control device. Of course, the first master control device can also be a collective term for all levels of control devices; that is, the first master control device can include all levels of control devices of the controlled device. For example, Figure 2 This is a schematic diagram of the structure of a microgrid system provided in an embodiment of this application, such as... Figure 2As shown, the microgrid system may include multiple controlled devices (e.g., controlled device 1-controlled device n), a second-level control device, and a first-level control device. All controlled devices are electrically connected to the second-level control device, which is also electrically connected to the first-level control device. The first-level control device sends first control information to the second-level control device. The second-level control device receives the first control information from the first-level control device and then sends the first control information to the multiple controlled devices. Each controlled device receives the first control information and, according to the start-up mode, performs a start-up operation on the target task corresponding to the controlled device when the control time arrives. For example, Figure 3 This is a schematic diagram of another microgrid system provided in an embodiment of this application, as shown below. Figure 3 As shown, this microgrid system is comparable to Figure 2 The microgrid system shown differs in that it lacks one level of control equipment, namely Figure 3 The microgrid system shown may include multiple controlled devices (e.g., controlled device 1-controlled device n) and a first-level control device. All controlled devices are electrically connected to the first-level control device. The first-level control device is used to send control information to the multiple controlled devices. Each controlled device receives the first control information and, according to the start-up mode, performs a start-up operation on the target task corresponding to its controlled device when the control time arrives.

[0041] The aforementioned first control information can be used to control fault recording; alternatively, it can be used to control black start; or it can be used to control station-level network construction. For example, the first control information can be a black start command, which is a specific command to initiate the black start process. The black start process refers to the process of restoring the entire power system using some equipment within the power system (usually generator sets with self-starting capabilities) after a complete power outage due to a fault. For example, the first control information can be a fault recording command, which is a signal that triggers the fault recorder to start working. A fault recorder is a device that records changes in various electrical quantities during a power system fault. For example, the first control information can be a station-level network construction command, which is a set of commands guiding the construction process and management activities of station-level network construction. The station-level network construction process refers to the process of constructing and managing a power network at the substation or power plant level. Of course, the embodiments of this application are not limited to the commands listed above and may include other commands, which will not be listed here.

[0042] The aforementioned microgrid system can be at least one of a photovoltaic system, energy storage system, wind power generation system, thermal conversion system, or liquid potential energy conversion system. Depending on the components of the microgrid system, the components of the multiple controlled devices will also differ. Therefore, the synchronous control method provided in this application embodiment is applicable to different scenarios. Based on this, the synchronous control method provided in this application embodiment will be described in detail below for different application scenarios.

[0043] Application scenario one: solar power generation.

[0044] A microgrid system can be a photovoltaic (PV) system, which may include multiple inverters (e.g., inverter 1 to inverter n) and a subarray controller. The subarray controller is connected to the multiple inverters. The subarray controller is used to aggregate and process the current output from the multiple PV modules. The inverters are used to convert the DC current aggregated by the subarray controller into AC current to match the standard frequency and voltage of the power grid. The PV system generates electricity during the day and consumes electricity at night. The multiple inverters in the PV system are the main power consumers. To reduce the power consumption of the multiple inverters, they are typically powered off at night when there is no sunlight to save energy. The next day, when there is sunlight, the multiple inverters synchronously start up. To enable the multiple inverters to synchronously start up, in this embodiment, the subarray controller can send first control information to the multiple inverters. This first control information is a black start command, which may include a control time, the identifiers of the multiple inverters, the target task of each inverter, and the start-up mode for the inverter to execute the target task. Multiple inverters receive the black-start command and, upon the arrival of the control time, execute the black-start operation for their respective target tasks according to the start-up mode. This ensures that multiple inverters perform black-start operations simultaneously after receiving the command, reducing the time lag between their black-start execution and thus guaranteeing the stability of the photovoltaic system.

[0045] Application scenario two: energy storage scenario.

[0046] A microgrid system can be an energy storage system, which may include multiple energy storage devices and a subarray controller. The multiple energy storage devices may include multiple energy storage converters (e.g., energy storage converter 1 to energy storage converter n) and multiple batteries. Each energy storage converter is connected to one of the batteries. Each energy storage converter is also connected to the subarray controller. The subarray controller monitors the real-time status of the multiple batteries, including parameters such as voltage, current, temperature, and charge level. Furthermore, the subarray controller generates first control information based on the real-time status of the multiple batteries, which may include the charging time for each battery. The subarray controller sends the first control information to the multiple energy storage converters, and the multiple energy storage converters simultaneously charge the multiple batteries when the charging time arrives. In this way, after receiving the first control information, the multiple energy storage converters simultaneously charge the multiple batteries when the charging time arrives. This coordinated charging by multiple energy storage converters not only improves charging efficiency but also extends battery life and enhances the overall reliability of the system.

[0047] Of course, fault recording devices can be configured on multiple energy storage converters and subarray controllers. Each fault recording device can independently collect data from local sensors, which can include detailed information about the normal operating status of the energy storage converter and the moment of failure. The subarray controller uses this data to determine whether multiple energy storage converters have failed. When any fault recording device detects that its corresponding energy storage converter meets preset fault conditions, the subarray controller generates first control information, which is a fault recording command. This command can include the recording time. The subarray controller sends this command to multiple fault recording devices corresponding to the multiple energy storage converters. Upon receiving the command, each fault recording device immediately starts recording when the recording time arrives, ensuring synchronized recording across the entire system. Therefore, the collaborative operation of multiple fault recording devices can significantly improve the safety and stability of the energy storage system, providing strong support for rapid and effective response to emergencies.

[0048] Application scenario three: wind power generation.

[0049] A microgrid system can be a wind power system, which may include multiple wind turbine generators and a subarray controller. The multiple wind turbine generators can be multiple wind turbine units (e.g., wind turbine unit 1 to wind turbine unit n). The subarray controller is connected to the multiple wind turbine generators. Based on the operating data and environmental conditions of each wind turbine unit, the subarray controller determines the synchronization speed of each turbine's generator. The subarray controller generates first control information, which is a start command, and the start command may include the synchronization speed. The subarray controller sends the start command to the multiple wind turbines. After receiving the start command, the multiple wind turbines calculate the time required to reach the synchronization speed based on their respective information to obtain the start time. The multiple wind turbines execute the start operation according to their respective start times to ensure that they reach the synchronization speed at the same time. In this way, after receiving the start command, the multiple wind turbines execute the start operation according to their respective start times to reach the synchronization speed at the same time. Through reasonable planning and coordination, the simultaneous achievement of synchronization speed by multiple wind turbine units ensures the stability and reliability of the power system.

[0050] Application scenario four: thermal conversion scenario.

[0051] A microgrid system can be a thermal conversion system, which may include multiple thermal conversion devices (e.g., thermal conversion device 1 to thermal conversion device n) and a subarray controller. All thermal conversion devices are connected to the subarray controller. The subarray controller generates first control information based on the operating parameters of the multiple thermal conversion devices, such as temperature, pressure, and flow rate. This first control information can be a parameter control command, used to control and execute parameter adjustment operations when the operating parameters of the thermal conversion devices do not meet standard operating parameters. The parameter control command may include a command end time. The subarray controller sends the parameter control command to the multiple thermal conversion devices. After receiving the parameter control command, the multiple thermal conversion devices control themselves to reach the standard operating parameters at the command end time. By synchronously controlling the operating parameters of multiple thermal conversion devices, the entire system can operate in an optimal state, reducing energy waste and improving energy utilization efficiency.

[0052] Application Scenario 5: Liquid Potential Energy Conversion Scenario.

[0053] A microgrid system can be a liquid potential energy conversion system, which may include multiple liquid pump devices (e.g., liquid pump device 1 to liquid pump device n) and a subarray controller. The multiple liquid pump devices are connected to the subarray controller. The subarray controller generates first control information based on the operating status of each liquid pump device in the liquid potential energy conversion system, such as water level, flow rate, and grid demand parameters. This first control information can be a station-level grid connection command. For example, when the grid frequency fluctuates, the subarray controller calculates instructions to adjust the operating parameters of each liquid pump device to maintain grid stability. The station-level grid connection command can carry the command initiation time. The subarray controller sends the station-level grid connection command to the multiple liquid pump devices. After receiving the station-level grid connection command, each liquid pump device adjusts its operating parameters when the command initiation time is reached. By enabling multiple devices to work collaboratively, the station-level grid connection command is better executed, achieving efficient and stable operation of the liquid potential energy conversion system.

[0054] The application scenarios described above are merely illustrative examples. The control commands in each application scenario are not limited to those listed, and may include other commands, such as combinations of commands in the above scenarios that do not conflict. This application does not impose specific limitations on these combinations. Of course, the application scenarios of the synchronization control method provided in this application are not limited to those listed above, and may include other application scenarios, such as nuclear power generation systems. These will not be listed individually in this application.

[0055] The following describes in detail a synchronization control method provided by an embodiment of this application with reference to examples. Figure 4 This is a flowchart illustrating a synchronization control method provided in an embodiment of this application. Figure 4 As shown, this method can be applied to Figure 2 or Figure 3 The microgrid system shown includes a first master control device and multiple controlled devices. The method may include: S401-S404 (some of which are optional).

[0056] S401, the first master control device and multiple controlled devices synchronize their time.

[0057] This should be understood as ensuring that the clock of the primary control device and the clocks of the multiple controlled devices are kept in sync.

[0058] To ensure clock synchronization between the primary control device and multiple controlled devices, time synchronization is performed based on a time synchronization strategy. For example, the time synchronization strategy may include any of the following: an Ethernet clock synchronization protocol; a real-time Ethernet communication protocol; a time synchronization protocol algorithm; or power line carrier communication technology. The Ethernet clock synchronization protocol may include clock synchronization protocols such as Ethernet 1588. The real-time Ethernet communication protocol may include the EtherCat distributed clock synchronization protocol. Time synchronization protocol algorithms are typically applied to third-party devices that do not support high-precision clock synchronization. This means that if multiple controlled devices include third-party devices that do not support high-precision clock synchronization, then a time synchronization protocol algorithm can be used to achieve time synchronization among these devices.

[0059] For example, a time synchronization strategy may include the Ethernet 1588 clock synchronization protocol. For instance... Figure 5 As shown, the clock of the first master device sends a synchronization message with timestamp t1 to the clock of the controlled device at time t1. The clock of the controlled device receives the synchronization message from the clock of the first master device at time t2. The clock of the controlled device sends a delay request message (delay_req) to the clock of the first master device at time t3. The clock of the first master device receives the delay_req message from the clock of the controlled device at time t4 and generates a delay response message (delay_resp) and sends it to the clock of the first master device. The round-trip time between the first master device and the controlled device is (t4-t1)-(t3-t2). The time deviation of the controlled device relative to the control device is [(t2-t1)-(t4-t3)] / 2. Therefore, the controlled device adjusts its local time according to this time deviation to achieve time synchronization.

[0060] For example, a time synchronization strategy may include power line carrier communication technology. For instance... Figure 6 As shown, a first master control device is connected to multiple controlled devices via power cables. The microcontroller unit (MCU) of the first master control device obtains Coordinated Universal Time (UTC) based on a time synchronization strategy. The first master control device obtains the Network Time Base (NTB) values ​​of the multiple controlled devices at a first moment. The first master control device calculates the difference between the UTC standard time and the network time base NTB value. The first master control device encapsulates the difference in a message and sends the message to the multiple controlled devices. The multiple controlled devices receive the message and read the difference from the message. Each controlled device's MCU determines its UTC standard time based on the NTB value and the difference at a second moment.

[0061] The above only uses the Ethernet 1588 clock synchronization protocol and power line carrier communication technology as examples. Of course, time synchronization strategies can also include other synchronization strategies, which will not be listed here.

[0062] In this way, by synchronizing the time of the first master control device with multiple controlled devices, it is ensured that the first master control device and multiple controlled devices are on the same time base, which effectively ensures that multiple controlled devices can simultaneously execute the work corresponding to the control commands.

[0063] S402, The first master control device generates first control information, which includes control time, identifiers of multiple controlled devices, target task of each controlled device, and start mode of the controlled device to start executing the target task.

[0064] The control time can be either a start time or an end time. The start time refers to the moment when multiple controlled devices begin operation. The end time refers to the moment when multiple controlled devices start operation based on the first control information and that operation ends. The target task refers to each controlled device completing its respective work objective. The start mode refers to starting immediately at the control time, starting at a specified time after the control time, or starting at the end of the control time.

[0065] As described above, the first control information can be used to control fault recording; or, the first control information can also be used to control black start; or, the first control information can also be used to control station-level network construction.

[0066] The timing of the first control information generation varies depending on the content indicated by the first control information.

[0067] Example 1: The first control information is used to control the fault recording waveform. The generation of the first control information may include the following timing.

[0068] Triggering Scenario 1: The first master control device monitors the electrical signal on the power cable. When the electrical signal exceeds a threshold, it generates the first control information. For fault recording scenarios, the first master control device can trigger the generation of the first control information, i.e., fault recording control information, by monitoring abnormal fluctuations in the electrical signal on the power cable.

[0069] Triggering opportunity two: The first master control device receives a request for fault recording from at least one of the multiple controlled devices, and generates first control information based on the request. For fault recording scenarios, the first master control device can trigger the generation of first control information, i.e., fault recording control information, by receiving a request from at least one of the lower-level controlled devices.

[0070] Triggering Circumstance Three: The microgrid system also includes a second master control device, which is the superior control device of the first master control device. The first master control device receives second control information sent by the second master control device. This second control information is used to trigger the first master control device to generate first control information. Specifically, the second control information is generated by the second master control device monitoring the electrical signal on the power cable and when the electrical signal exceeds a threshold. For fault recording scenarios, the first master control device can also have a superior control device, namely the second master control device. In this case, the second master control device can trigger the first master control device to generate first control information by sending second control information to it. The second control information is generated by the second master control device by monitoring abnormal fluctuations in the electrical signal on the power cable.

[0071] In the fourth triggering scenario, the microgrid system also includes a second master control device, which is the superior control device of the first master control device. The first master control device receives second control information sent by the second master control device. This second control information is used to trigger the first master control device to generate first control information. Specifically, the second control information is generated by the second master control device based on a request for fault recording reported by the first master control device. For fault recording scenarios, the first master control device can also have a superior control device, namely the second master control device. In this case, the second master control device can trigger the first master control device to generate first control information by sending the second control information to it. The second control information is generated by the second master control device receiving a request reported by the subordinate first master control device.

[0072] Example 2: The first control information is used to control black start. The generation of the first control information can include the following triggering events. For example, the microgrid system also includes a third master control device, which is the superior control device of the first master control device; the first master control device receives third control information sent by the third master control device, and this third control information is used to trigger the first master control device to generate the first control information. For the black start scenario, the first master control device can trigger the generation of the first control information, i.e., the black start control information, by receiving control information sent by the superior control device.

[0073] Of course, in this embodiment, the information that triggers the generation of the first control information is not limited to the above information, but may also include other information, such as metering values ​​or energy supply and demand information from metering instruments such as electricity meters, analog or digital signals from voltage or current acquisition devices, and weather status data from meteorological monitoring equipment.

[0074] Besides the different triggering times for generating the first control information, the content of the generated first control information also differs. The following explanation addresses different systems.

[0075] For example, the microgrid system is a photovoltaic system, and the microgrid system also includes a box-type transformer, with multiple controlled devices connected to the same conductor of the box-type transformer. The first master control device collects at least one of the following for each of the multiple controlled devices, based on the third control information: DC input information, weather and sunshine forecast information, rated power, apparent power, or internal power topology model. The first master control device determines the output capacity of each of the multiple controlled devices based on the DC input information, weather and sunshine forecast information, rated power, apparent power, or internal power topology model. The first master control device determines the control time, the identifiers of the multiple controlled devices, the target task of each of the multiple controlled devices, and the startup mode for the controlled devices to execute the target task, based on the number of devices in the microgrid system, the output capacity of each controlled device, and the load of the box-type transformer, to generate the first control information.

[0076] For photovoltaic system scenarios, the first master control device can collect at least one of the following from multiple controlled devices: DC input information, weather and solar radiation forecast information, rated power, apparent power, or internal power topology model. Based on this information, it determines the output capacity of each controlled device. Then, based on the number of devices in the microgrid system, the output capacity of each controlled device, and the load of the box-type transformer, it determines the first control information. For example, the target output power of each controlled device participating in black start can be calculated using the following formula. Among them, VA i-out It is the target output power of the controlled device i, VA i VA is the output capability of the i-th controlled device participating in the black start process. load Here, α represents the load size, n represents the total number of controlled devices participating in the black start, and α is the adjustment coefficient. Thus, the generation of the first control information is determined by combining the information of each controlled device in the photovoltaic system, allowing the first control information to be adjusted according to the actual situation, resulting in greater flexibility and practicality. Furthermore, by combining the information of each controlled device in the photovoltaic system, a target controlled device can be selected to perform a black start, effectively ensuring that multiple target controlled devices perform black starts simultaneously.

[0077] For example, the microgrid system is an energy storage system, and it also includes a box-type transformer, with multiple controlled devices connected to the same conductor. A first master control device collects at least one of the following parameters for each of the multiple controlled devices: voltage, frequency, rated power, droop factor, or state of charge. Based on the third control information, the first master control device determines the output capacity of each of the multiple controlled devices. Based on the number of devices in the microgrid system, the output capacity of each controlled device, and the load of the box-type transformer, the first master control device determines the control time, the identifiers of the multiple controlled devices, the target task of each of the multiple controlled devices, and the startup mode for the controlled devices to execute the target task, in order to generate first control information.

[0078] For energy storage system scenarios, the first master control device can collect at least one of the following parameters for each controlled device: voltage, frequency, rated power, droop factor, or state of charge. Based on this information, the output capacity of each controlled device is determined. Then, based on the number of devices in the microgrid system, the output capacity of each controlled device, and the load of the box-type transformer, the first control information is determined. In this way, the generation of the first control information incorporates information from each controlled device in the energy storage system, allowing for adjustments based on actual conditions, thus increasing flexibility and practicality. Furthermore, by incorporating information from each controlled device in the charging system, a target controlled device can be selected for black start, effectively ensuring that multiple target controlled devices can perform black start simultaneously.

[0079] In some embodiments, when AC power is used, the first control information further includes a threshold voltage or threshold current that triggers the controlled device to perform a start-up operation. The threshold voltage can include any voltage, such as a peak voltage or 0. The threshold current can include any current, such as a peak current or 0. Typically, multiple controlled devices reach the threshold voltage or threshold current at the same time. The first control information also includes the threshold voltage or threshold current that triggers the controlled device to perform a start-up operation. Thus, the synchronous control of multiple controlled devices is not only based on control time but also includes phase synchronization, making the synchronous control of multiple controlled devices more precise and consistent.

[0080] For example, such as Figure 7As shown above, generating the first control information requires generating different control commands for different controlled objects. For example, when generating a fault recording command, it is necessary to generate the start time T of synchronous recording, the identity document (ID) of the controlled device, and the fault recording duration information can be carried through the target value field. For example, when generating a black start command, it is necessary to generate the start time T of synchronous start, the ID of the controlled device, and the target power output value of the controlled device. The above control command frame format may include a frame header, control time, device identifier, target task, start mode, threshold voltage or threshold current, and frame tail. Among them, the frame header is used to indicate the control frame behavior ID and frame length information. The control time is used to agree on the start time. The device identifier is the ID of the controlled device. The target task is the control target value of the controlled device such as reactive power, active power, charging and discharging, speed, temperature, and opening degree. The start mode may include start at the agreed time T, start to the target value at the agreed time T, or start at the agreed time T. The frame tail is used to indicate the end of the frame and cyclic redundancy check (CRC) information.

[0081] S403, The first master control device sends first control information to multiple controlled devices, and correspondingly, the multiple controlled devices are used to receive the first control information.

[0082] S404. When the control time arrives, multiple controlled devices shall perform a start operation on the target task corresponding to the controlled device according to the start mode.

[0083] In this context, the multiple first controlled devices can be all of the multiple controlled devices. Alternatively, the multiple first controlled devices can be some of the multiple controlled devices.

[0084] As mentioned above, the implementation of S402 varies depending on the content of the first control information.

[0085] Example 1: The control time is the startup time, such as time t11. Startup modes include starting immediately at the startup time. For example... Figure 8 As shown, the multiple controlled devices may include controlled device 1, controlled device 2, and controlled device 3. The first master control device sends first control information at time t12, which is before time t11. Controlled devices 1, 2, and 3 all receive the first control information. Each controlled device determines that upon arrival at time t11, it will immediately execute a start operation on the target task corresponding to its controlled device.

[0086] Example 2, where the control time is the end time, such as time t21. The startup mode includes stopping startup at the end time. For example... Figure 9As shown, multiple controlled devices may include controlled device 1, controlled device 2, and controlled device 3. The first master control device sends first control information at time t22, which is before time t21. Controlled devices 1, 2, and 3 receive the first control information at different times and initiate the startup operation for the target task corresponding to each controlled device at different times, ensuring that the target task is completed simultaneously at time t21. The startup time of each controlled device for executing the target task can be determined based on the status information of each controlled device.

[0087] Example 3: The first control information also includes a threshold voltage that triggers the controlled device to perform a start-up operation; the threshold voltage is the voltage zero-crossing point. For example... Figure 10 As shown, multiple controlled devices may include controlled device 1, controlled device 2, and controlled device 3. The first master control device sends first control information at time t31, which is before the voltage zero-crossing point. After receiving the information, controlled devices 1, 2, and 3 determine that they will simultaneously execute a start operation on the target task corresponding to each controlled device at the next voltage zero-crossing point.

[0088] It is evident that multiple controlled devices can start or stop simultaneously to perform the startup operation of the target task, thereby achieving synchronous control of multiple controlled devices and realizing the purpose of synchronous startup of multiple controlled devices. This effectively ensures that multiple controlled devices start up at the same time and reduces the time difference between the startup of multiple controlled devices.

[0089] In some embodiments, before executing S402, the synchronization control method provided in this application embodiment may further include: S405, the first master control device determines a target controlled device from the multiple controlled devices based on the information of each controlled device among the multiple controlled devices. The target controlled device may be all devices among the multiple first controlled devices, or some devices among the multiple first controlled devices. Correspondingly, S403 may be implemented as: the first master control device sends first control information to the target controlled device.

[0090] Continuing with the aforementioned solar power generation scenario, the microgrid system is a photovoltaic system, and the controlled equipment includes an inverter. The first piece of information may include at least one of the following: inverter DC input information, weather and sunshine forecast information, inverter rated power, inverter apparent power, or inverter internal power topology model. The inverter DC input information refers to information related to the DC power supply input to the inverter. The weather and sunshine forecast information refers to predictions of future weather conditions such as sunshine intensity and duration based on meteorological data and models. The inverter rated power refers to the maximum AC power that the inverter can continuously and stably output under normal operating conditions. The inverter apparent power (S) is equal to the square root of the sum of the squares of the inverter's active power (P) and reactive power (Q), i.e., S = P² + Q². The inverter apparent power (S) reflects the total power capacity absorbed by the inverter from the grid or DC power supply. The inverter internal power topology model is a mathematical description model of the inverter's internal circuit structure and power transmission path. The internal power topology model of the inverter illustrates how it converts direct current (DC) to alternating current (AC). Based on the information provided by each inverter in the multiple inverters, the first master control device identifies multiple target inverters. Then, the first master control device sends first control information and start-up conditions to these target inverters.

[0091] Continuing with the aforementioned energy storage scenario, the microgrid system is the energy storage system, and the controlled equipment includes energy storage devices. The first piece of information may include at least one of the following: voltage, frequency, reference power, droop coefficient, or state of charge. Voltage refers to the potential difference across the energy storage device. Frequency refers to the frequency of the alternating current synchronized with the grid when the energy storage device operates in an AC system. Reference power is a set power value for the energy storage device during operation, used to control its charging and discharging behavior. The reference power can be set based on grid demand, load demand, or the energy storage system's own management strategy. The droop coefficient (kp) describes the power of the energy storage device, expressed as ΔP = kpΔf, where ΔP is the power change and Δf is the frequency change. The state of charge represents the percentage of the energy storage device's current remaining capacity relative to its rated capacity, typically ranging from 0 to 1 (or 0%-100%). For example, for a battery with a rated capacity of 100Ah, if the current state of charge (SOC) is 0.5% (or 50%), it means the battery currently has 50Ah of remaining capacity. Then, the first master control device determines the target controlled device from among the multiple energy storage devices based on the aforementioned information from each of the multiple energy storage devices. Afterwards, the first master control device sends first control information and start-up execution conditions to the target controlled device.

[0092] Continuing with the aforementioned wind power generation scenario, the microgrid system is a wind power generation system, and the controlled equipment includes wind power generation equipment. The first piece of information includes at least one of the following: rated power, apparent power, power topology model, weather forecast information, wind speed range, wind direction change, or wake effect. Rated power refers to the maximum power that the wind power generation equipment can continuously output under standard operating conditions (typically around 15 m / s wind speed). Apparent power refers to the total power of the wind power generation equipment at a given moment, including active and reactive power. The power topology model is a mathematical model describing the internal electrical connections and power flow of the wind power generation equipment. Weather forecast information refers to the meteorological conditions of the wind farm over a future period obtained through meteorological models and sensors. Wind speed range refers to the range of wind speeds within which the wind power generation equipment can operate. Wind direction change refers to the characteristics of wind direction change over time. Wake effect refers to the impact of upstream wind turbine disturbances on downstream turbines during the operation of the wind power generation equipment. Based on the aforementioned information from each of the multiple wind power generation devices, the first master control device identifies the target controlled device from among the multiple wind power generation devices. Then, the first master control device sends the first control information and start-up execution conditions to the target controlled device.

[0093] Continuing with the aforementioned heat conversion scenario, the microgrid system is a heat conversion system, and the controlled equipment includes heat conversion devices. The first piece of information includes at least one of the following: a planned heating temperature curve, inlet / outlet temperature difference, heat conversion method, heat transfer method, or response speed. The planned heating temperature curve is a pre-planned curve showing the heating temperature changes of the heat conversion devices over different time periods, based on user heat demand and the heat source's supply capacity. The inlet / outlet temperature difference refers to the temperature difference between the fluid at the inlet and outlet of the heat conversion device. The heat conversion method can include direct contact heat conversion, indirect heat conversion, or regenerative heat conversion. The heat transfer method can include heat conduction, heat convection, or heat radiation. The response speed refers to the heat conversion device's ability to respond to changes in heating load, i.e., its ability to quickly adjust parameters such as heating temperature and flow rate when user heat demand changes. Therefore, the first master control device determines the target controlled device from among the multiple heat conversion devices based on the above information. Then, the first master control device sends first control information and start-up conditions to the target controlled device.

[0094] Continuing with the aforementioned liquid potential energy conversion scenario, the microgrid system is a liquid potential energy conversion system. The controlled devices include liquid pumps. The first piece of information includes at least one of the following: flow rate, pressure, liquid viscosity, head, efficiency range, or liquid level. Flow rate refers to the volume of liquid delivered by the pump per unit time. Pressure refers to the maximum head the pump can provide or the pressure at the outlet. Liquid viscosity refers to the liquid's ability to resist shear forces, usually expressed as the viscosity index or kinematic viscosity. Head refers to the height the pump can lift the liquid, which can also be understood as the total resistance overcome. Efficiency range refers to the ratio of input power to output power when the pump is operating under optimal conditions. Liquid level refers to the height of the liquid surface at the pump inlet or in the tank. Therefore, the first master control device determines the target controlled device from among the multiple liquid pumps based on the above information. Then, the first master control device sends the first control information and start-up execution conditions to the target controlled device.

[0095] In summary, the first master control device can determine the target controlled device that needs to be synchronously controlled based on the first information of each of the multiple controlled devices. The first master control device sends first control information to the determined target controlled device, so that the target controlled device simultaneously starts the start operation of the target task corresponding to the controlled device. In this way, some controlled devices can be selectively started, which can be selected according to the actual situation, making it highly practical.

[0096] In some embodiments, the synchronization control method provided in this application may further include: S406, a first master control device monitors the electrical signal on the power cable, and when the electrical signal is greater than a threshold, updates the first control information to obtain updated first control information, the updated first control information including an updated control time, an updated target task, and an updated startup mode. S407, the first master control device sends the updated first control information to multiple controlled devices. S408, the multiple controlled devices receive the updated first control information, and when the updated control time arrives, execute a startup operation on the updated target task corresponding to the controlled device according to the updated startup mode.

[0097] In practical applications, taking fault recording scenarios as an example, Figure 11 This is a flowchart illustrating another synchronization control method provided in an embodiment of this application. Figure 11As shown, the method may include: S1101, time synchronization between a first master control device and multiple controlled devices. The implementation of S1101 is described in S401 and will not be repeated here. S1102, the first master control device monitors the electrical signal on the power cable. S1103, if the electrical signal exceeds a threshold, the first master control device determines whether to generate first control information based on collected information (such as energy supply and demand information, weather status, etc.). If it is determined that first control information should be generated, S1104 is executed; if it is determined that first control information should not be generated, an end action is executed. S1104, the first master control device sends the first control information to multiple controlled devices. S1105, when the control time arrives, the multiple controlled devices perform a start operation on the target task corresponding to the controlled device according to the start mode. Afterwards, S1102, where the first master control device monitors the electrical signal on the power cable, continues to be executed. Continuing with S1103, if the electrical signal exceeds the threshold, update the first control information to obtain updated first control information, which includes updated control time, updated target task, and updated startup mode. Continuing with S1104, the first master control device sends the updated first control information to multiple controlled devices. Continuing with S1105, the multiple controlled devices receive the updated first control information and, upon the arrival of the updated control time, execute the startup operation for the updated target task corresponding to each controlled device according to the updated startup mode.

[0098] During the synchronous control of multiple controlled devices, the first master control device can also monitor the electrical signal on the power cable in real time. When the electrical signal is greater than the threshold, it updates the first control information to obtain the updated first control information, thereby re-controlling multiple controlled devices to achieve synchronous control. It can make real-time adjustments according to real-time changes, making it more flexible and practical.

[0099] The above description is merely a specific embodiment of this application, but the scope of protection of this application 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 application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0100] In the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. "And / or" in this document is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone.

[0101] 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. Therefore, 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 application, unless otherwise stated, "a plurality of" means two or more.

[0102] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0103] It is understood that the aforementioned communication devices, etc., include hardware structures and / or software modules corresponding to the execution of each function in order to achieve the above-mentioned functions. Those skilled in the art should readily recognize that, based on the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein, the embodiments of this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in a hardware-driven or software-driven manner 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 the embodiments of this application.

[0104] This application embodiment can divide the above-mentioned communication equipment into functional modules according to the above method examples. For example, each function can be divided into its own functional module, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. It should be noted that the module division in this application embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0105] Through the above description of the embodiments, those skilled in the art will clearly understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. The specific working process of the system, device, and unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

Claims

1. A microgrid system, characterized in that, The microgrid system includes a first master control device and multiple controlled devices, and the clocks of the first master control device and the multiple controlled devices are kept in the same time. The first master control device is used to generate first control information, which includes control time, identifiers of the plurality of controlled devices, target task of each of the plurality of controlled devices, and startup mode of the controlled device to start executing the target task; The first master control device is also used to send the first control information to the plurality of controlled devices; The plurality of controlled devices are used to receive the first control information; The plurality of controlled devices are also configured to perform a startup operation on the target task corresponding to the controlled device according to the startup mode when the control time arrives.

2. The microgrid system according to claim 1, characterized in that, The first main control device is also used to monitor the electrical signal on the power cable. When the electrical signal is greater than the threshold, the first control information is updated to obtain the updated first control information. The updated first control information includes the updated control time, the updated target task, and the updated start mode. The first master control device is also used to send the updated first control information to the plurality of controlled devices; The plurality of controlled devices are also configured to receive the updated first control information, and when the updated control time arrives, to perform a startup operation on the updated target task corresponding to the controlled device according to the updated startup mode.

3. The microgrid system according to claim 1, characterized in that, The first control information is used to control the fault recording waveform; The first main control device is also used to monitor electrical signals on power cables, and generate the first control information when the electrical signal exceeds a threshold; or, The first master control device is also configured to receive a request for fault recording reported by at least one of the plurality of controlled devices, and generate the first control information according to the request.

4. The microgrid system according to claim 1, characterized in that, The microgrid system also includes a second master control device, which is an upstream control device of the first master control device, and the first control information is used to control the fault recording. The first master control device is also used to receive second control information sent by the second master control device, the second control information being used to trigger the first control device to generate the first control information; The second control information is generated by the second master control device monitoring the electrical signal on the power cable and when the electrical signal is greater than a threshold; or, the second control information is generated by the second master control device receiving a request for fault recording from the first master control device and generating the request accordingly.

5. The microgrid system according to claim 1 or 2, characterized in that, The microgrid system also includes a third master control device, which is the superior control device of the first master control device; the first control information is used to control black start; The first master control device is also used to receive third control information sent by the third master control device, the third control information being used to trigger the first control device to generate the first control information.

6. The microgrid system according to claim 5, characterized in that, The microgrid system is a photovoltaic system, and the microgrid system also includes a box-type transformer, with the multiple controlled devices connected to the same conductor of the box-type transformer; The first master control device is also used to collect, based on the third control information, at least one of the following for each of the plurality of controlled devices: DC input information, weather and light prediction information, rated power, apparent power, or internal power topology model; The first master control device is also used to determine the output capability of each of the plurality of controlled devices based on at least one of the DC input information, weather and light prediction information, rated power, apparent power or internal power topology model; The first master control device is further configured to determine the control time, the identifier of the plurality of controlled devices, the target task of each of the plurality of controlled devices, and the start mode of the controlled device to start executing the target task based on the number of devices in the microgrid system, the output capacity of each controlled device, and the load of the box transformer, so as to generate the first control information.

7. The microgrid system according to claim 5, characterized in that, The microgrid system is an energy storage system, and the microgrid system also includes a box-type transformer, with the multiple controlled devices connected to the same conductor of the box-type transformer; The first master control device is also used to collect at least one of the following for each of the plurality of controlled devices: voltage, frequency, rated power, droop factor, or state of charge, based on the third control information. The first master control device is also used to determine the output capability of each of the plurality of controlled devices based on at least one of the voltage, frequency, rated power, droop factor or state of charge of each controlled device; The first master control device is further configured to determine the control time, the identifier of the plurality of controlled devices, the target task of each of the plurality of controlled devices, and the start mode of the controlled device to start executing the target task based on the number of devices in the microgrid system, the output capacity of each controlled device, and the load of the box transformer, so as to generate the first control information.

8. The microgrid system according to any one of claims 1-7, characterized in that, In the case of alternating current, the first control information also includes a threshold voltage or threshold current that triggers the controlled device to perform a start-up operation.

9. The microgrid system according to any one of claims 1-8, characterized in that, The first master control device and the plurality of controlled devices are connected via a power line carrier communication PLC network. The first master control device is also used to send a first message to the plurality of controlled devices, the first message carrying the time difference between Coordinated Universal Time (UTC) and the network time base (NTB) value of the plurality of controlled devices at a first moment; Each of the plurality of controlled devices is further configured to receive the first message and adjust the UTC standard time of the controlled device according to the time difference and the NTB value on the controlled device at the second time.

10. A synchronization control method, characterized in that, The method is applied to a microgrid system, the microgrid system including a first master control device and multiple controlled devices, wherein the clock of the first master control device and the clocks of the multiple controlled devices are kept in sync; the method includes: The first master control device generates first control information, which includes control time, the identifier of the plurality of controlled devices, the target task of each of the plurality of controlled devices, and the start mode of the controlled device to start executing the target task; The first master control device sends the first control information to the plurality of controlled devices; The plurality of controlled devices receive the first control information; When the control time arrives, the multiple controlled devices perform a startup operation on the target task corresponding to the controlled device according to the startup mode.

11. The method according to claim 10, characterized in that, The method further includes: The first master control device monitors the electrical signal on the power cable. When the electrical signal is greater than a threshold, it updates the first control information to obtain updated first control information. The updated first control information includes updated control time, updated target task, and updated startup mode. The first master control device sends the updated first control information to the plurality of controlled devices; The plurality of controlled devices receive the updated first control information, and when the updated control time arrives, they perform a startup operation on the updated target task corresponding to the controlled device according to the updated startup mode.

12. The method according to claim 10, characterized in that, The first control information is used to control the fault recording; the first master control device generates the first control information, including: The first master control device monitors the electrical signal on the power cable, and generates the first control information when the electrical signal exceeds a threshold; or, The first master control device receives a request for fault recording from at least one of the plurality of controlled devices, and generates the first control information based on the request.

13. The method according to claim 10, characterized in that, The microgrid system also includes a second master control device, which is an upstream control device of the first master control device, and the first control information is used to control the fault recording. The first master control device receives the second control information sent by the second master control device, and the second control information is used to trigger the first control device to generate the first control information; The second control information is generated by the second master control device monitoring the electrical signal on the power cable and when the electrical signal is greater than a threshold; or, the second control information is generated by the second master control device receiving a request for fault recording from the first master control device and generating the request accordingly.

14. The method according to claim 10 or 11, characterized in that, The microgrid system also includes a third master control device, which is the superior control device of the first master control device; the first control information is used to control black start; The first master control device generates first control information, including: The first master control device receives third control information sent by the third master control device, and the third control information is used to trigger the first control device to generate the first control information.

15. The method according to claim 14, characterized in that, The microgrid system is a photovoltaic system, and the microgrid system also includes a box-type transformer, with the multiple controlled devices connected to the same conductor of the box-type transformer; after the first master control device receives the third control information sent by the third master control device, the method further includes: The first master control device collects at least one of the following from each of the plurality of controlled devices: DC input information, weather and light prediction information, rated power, apparent power, or internal power topology model, based on the third control information. The first master control device determines the output capability of each of the plurality of controlled devices based on at least one of the DC input information, weather and light prediction information, rated power, apparent power or internal power topology model; The first master control device determines the control time, the identifier of the plurality of controlled devices, the target task of each of the plurality of controlled devices, and the start mode of the controlled device to start executing the target task based on the number of devices in the microgrid system, the output capacity of each controlled device, and the load of the box transformer, so as to generate the first control information.

16. The method according to claim 14, characterized in that, The microgrid system is an energy storage system, and the microgrid system also includes a box-type transformer, with the multiple controlled devices connected to the same conductor of the box-type transformer; After the first master control device receives the third control information sent by the third master control device, the method further includes: The first master control device collects at least one of the following for each of the plurality of controlled devices: voltage, frequency, rated power, droop factor, or state of charge, based on the third control information. The first master control device determines the output capability of each of the plurality of controlled devices based on at least one of the following: voltage, frequency, rated power, droop factor, or state of charge of each controlled device. The first master control device determines the control time, the identifier of the plurality of controlled devices, the target task of each of the plurality of controlled devices, and the start mode of the controlled device to start executing the target task based on the number of devices in the microgrid system, the output capacity of each controlled device, and the load of the box transformer, so as to generate the first control information.

17. The method according to any one of claims 10-16, characterized in that, In the case of alternating current, the first control information also includes a threshold voltage or threshold current that triggers the controlled device to perform a start-up operation.

18. The method according to any one of claims 10-17, characterized in that, The first master control device and the plurality of controlled devices are network-connected via a power line carrier communication PLC; it also includes: The first master control device sends a first message to the plurality of controlled devices, the first message carrying the time difference between Coordinated Universal Time (UTC) and the network time base (NTB) value of the plurality of controlled devices at a first moment; Each of the plurality of controlled devices receives the first message and adjusts its UTC standard time according to the time difference and the NTB value on the controlled device at the second time.

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