Grid-connected detection control device, method and circuit breaker

Abstract

The application provides a grid-connected detection control device, method and circuit breaker, comprising a first voltage dividing module, a second voltage dividing module and an MCU module; one end of the first voltage dividing module is connected with an incoming line end of the grid-connected detection control device, and the other end of the first voltage dividing module is connected with the MCU module; one end of the second voltage dividing module is connected with an outgoing line end of the grid-connected detection control device, and the other end of the second voltage dividing module is connected with the MCU module; the first voltage dividing module is used for voltage dividing sampling of the voltage of the incoming line end, obtaining a first voltage signal, and sending the first voltage signal to the MCU module. The development difficulty and the calculation burden are reduced. The grid-connected response time is shortened, the voltage difference and the phase difference in the grid-connected instant are smaller, the impact on the power grid is reduced, and the grid-connected quality and the power grid stability are improved.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and more specifically, to a grid-connected detection and control device, method, and circuit breaker. Background Technology

[0002] In new energy power generation systems such as photovoltaic and wind power, inverters and the power grid usually need to be connected and isolated through circuit breakers.

[0003] In existing technologies, circuit breakers are generally used only as switching devices and do not have the functions of electrical signal acquisition and grid connection detection. They cannot provide grid-side information support for inverters. Therefore, inverters need to acquire grid-side electrical signals on their own to achieve grid connection detection and perform grid connection control accordingly.

[0004] However, using existing technology, inverters need to be configured with dedicated voltage acquisition circuits, phase detection circuits, and other modules to acquire grid electrical signals. These modules not only occupy PCB space but also require additional component costs. At the same time, the inverter controller needs to process the acquired grid data, increasing the difficulty of software development and the computational burden. Summary of the Invention

[0005] The purpose of this application is to address the shortcomings of the prior art by providing a grid-connected detection and control device, method, and circuit breaker. By integrating a voltage module inside the circuit breaker, synchronous acquisition of data from the incoming and outgoing terminals is achieved. The acquired voltage difference and phase difference information is provided to the inverter or the circuit breaker can autonomously determine the grid connection timing, thereby solving the problem that the inverter needs to collect grid-side parameters on its own, resulting in a heavy hardware burden.

[0006] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows: In a first aspect, embodiments of this application provide a grid-connected detection and control device, including: a first voltage divider module, a second voltage divider module, and an MCU module; One end of the first voltage divider module is connected to the input terminal of the grid-connected detection and control device, and the other end of the first voltage divider module is connected to the MCU module. One end of the second voltage divider module is connected to the output terminal of the grid-connected detection and control device, and the other end of the second voltage divider module is connected to the MCU module; The first voltage divider module is used to perform voltage divider sampling on the voltage at the input terminal to obtain a first voltage signal, and send the first voltage signal to the MCU module; The second voltage divider module is used to perform voltage divider sampling on the voltage at the output terminal to obtain a second voltage signal, and then send the second voltage signal to the MCU module; The MCU module determines the voltage difference and phase difference between the input terminal and the output terminal based on the first voltage signal and the second voltage signal, and determines whether to output a grid connection command based on the voltage difference and phase difference.

[0007] Optionally, it may also include: a first metering module and a second metering module; One end of the first metering module is connected to the input end of the grid-connected detection and control device, and the other end of the first metering module is connected to the MCU module. One end of the second metering module is connected to the output end of the grid-connected detection and control device, and the other end of the second metering module is connected to the MCU module; The first metering module is used to collect the first electrical signal at the incoming end and send the first electrical signal to the MCU module; the second metering module is used to collect the second electrical signal at the outgoing end and send the second electrical signal to the MCU module. The MCU module is also used to measure the electrical signal between the input terminal and the output terminal based on the first electrical signal and the second electrical signal.

[0008] Optionally, the first metering module includes: a first voltage acquisition unit, a first phase acquisition unit, and a first metering unit; One end of the first voltage acquisition unit, one end of the first phase acquisition unit, and one end of the first metering unit are all connected to the input terminal; the other end of the first voltage acquisition unit, the other end of the first phase acquisition unit, and the other end of the first metering unit are all connected to the MCU module. The first voltage acquisition unit is used to acquire the first voltage at the input terminal and send the first voltage to the MCU module; The first phase acquisition unit is used to acquire the first phase of the incoming line and send the first phase to the MCU module; The first metering unit is used to collect the first electrical signal at the incoming line and send the first electrical signal to the MCU module.

[0009] Optionally, the second metering module includes: a second voltage acquisition unit, a second phase acquisition unit, and a second metering unit; The second voltage acquisition unit, the second phase acquisition unit, and the second metering unit are all connected to the MCU module; The second voltage acquisition unit is used to acquire the second voltage at the output terminal and send the second voltage to the MCU module; The second phase acquisition unit is used to acquire the second phase of the outgoing terminal and send the second phase to the MCU module; The second metering unit is used to collect the second electrical signal at the output terminal and send the second electrical signal to the MCU module.

[0010] Optionally, the MCU module is specifically used to: determine the zero-crossing times of the first voltage signal and the second voltage signal through the input capture function, and obtain the first rising zero-crossing point corresponding to the first voltage signal and the second rising zero-crossing point corresponding to the second voltage signal; The phase difference between the input terminal and the output terminal is determined based on the first rising zero-crossing point and the second rising zero-crossing point. The voltage difference between the input terminal and the output terminal is determined based on the first effective voltage value corresponding to the first voltage signal and the second effective voltage value corresponding to the second voltage signal.

[0011] Optionally, the MCU module is specifically used for: The voltage difference and phase difference are sent to the inverter so that the inverter can output a grid connection instruction to the MCU module based on the phase difference and voltage difference. After receiving the grid connection instruction sent by the inverter, the MCU module outputs a grid connection command based on the grid connection instruction.

[0012] Optionally, the MCU module is specifically used to: determine whether the phase difference is less than a phase threshold and whether the voltage difference is less than a voltage threshold; If the phase difference is less than the phase threshold and the voltage difference is less than the voltage threshold, then a grid connection command is output.

[0013] Optionally, it may also include: a power supply module and a low-voltage energy storage module; One end of the power module is connected to the input terminal, and the other end of the power module is connected to one end of the low-voltage energy storage module and the MCU module respectively. The other end of the low-voltage energy storage module is connected to the magnetic flux trip unit. The power module is used to supply power to the MCU module; the low-voltage energy storage module is used to charge when the voltage is normal; when the voltage is abnormal, the low-voltage energy storage module discharges and drives the magnetic flux trip unit to perform a tripping operation.

[0014] Secondly, embodiments of this application also provide a grid connection detection method, applied to the MCU module in the grid connection detection control device described in the first aspect, the method comprising: Obtain the first voltage signal sent by the first voltage divider module; Obtain the second voltage signal sent by the second voltage divider module; Based on the first voltage signal and the second voltage signal, the voltage difference and phase difference between the input terminal and the output terminal are determined, and whether to output a grid connection command is determined based on the voltage difference and phase difference.

[0015] Optionally, the MCU module measures the electrical signal between the input terminal and the output terminal based on the first electrical signal and the second electrical signal.

[0016] Optionally, the MCU module determines the zero-crossing times of the first voltage signal and the second voltage signal through the input capture function, thereby obtaining the first rising zero-crossing point corresponding to the first voltage signal and the second rising zero-crossing point corresponding to the second voltage signal. The phase difference between the input terminal and the output terminal is determined based on the first rising zero-crossing point and the second rising zero-crossing point. The voltage difference between the input terminal and the output terminal is determined based on the first effective voltage value corresponding to the first voltage signal and the second effective voltage value corresponding to the second voltage signal.

[0017] Optionally, the MCU module sends the voltage difference and phase difference to the inverter, so that the inverter outputs a grid connection instruction to the MCU module based on the phase difference and the voltage difference. After receiving the grid connection instruction sent by the inverter, the MCU module outputs a grid connection command based on the grid connection instruction.

[0018] Optionally, the MCU module determines whether the phase difference is less than a phase threshold and whether the voltage difference is less than a voltage threshold; If the phase difference is less than the phase threshold and the voltage difference is less than the voltage threshold, then a grid connection command is output.

[0019] Thirdly, embodiments of this application also provide a circuit breaker, including the grid connection detection and control device described in the first aspect.

[0020] The beneficial effects of this application are: This application provides a grid-connected detection and control device, method, and circuit breaker. A first voltage divider module samples the voltage at the input terminal to obtain a first voltage signal, which is then sent to an MCU module. A second voltage divider module samples the voltage at the output terminal to obtain a second voltage signal, which is also sent to the MCU module. The MCU module then determines the voltage difference and phase difference between the input and output terminals based on the first and second voltage signals, and determines whether to output a grid-connected command based on these differences. This allows for grid-connected data acquisition and control within the circuit breaker, solving the problem of inverters needing to collect grid-side parameters and incurring heavy hardware burdens in existing technologies. By having the MCU module within the circuit breaker autonomously determine grid-connected conditions and directly control the circuit breaker's operation, the grid-connected response time can be shortened, resulting in smaller voltage and phase differences at the moment of grid connection, reducing the impact on the grid, and improving grid-connected quality and grid stability. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of a grid-connected detection and control device provided in an embodiment of this application; Figure 2 This is a schematic diagram of the structure of the second grid-connected detection and control device provided in the embodiments of this application; Figure 3 This is a flowchart illustrating a grid connection detection and control method provided in an embodiment of this application. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the accompanying drawings in this application are for illustrative and descriptive purposes only and are not intended to limit the scope of protection of this application. Furthermore, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate operations implemented according to some embodiments of this application. It should be understood that the operations in the flowcharts may not be implemented in sequence, and steps without logical contextual relationships may be reversed or implemented simultaneously. In addition, those skilled in the art, guided by the content of this application, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts.

[0024] Furthermore, the described embodiments are merely some, not all, of the embodiments of this application. The components of the embodiments of this application described and illustrated herein can typically be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0025] It should be noted that the term "comprising" will be used in the embodiments of this application to indicate the presence of the features declared thereafter, but does not exclude the addition of other features.

[0026] Figure 1 This is a schematic diagram of the structure of a grid-connected detection and control device provided in an embodiment of this application, as shown below. Figure 1 As shown, the grid-connected detection and control device may include: a first voltage divider module 10, a second voltage divider module 11, and an MCU module 13.

[0027] One end of the first voltage divider module 10 is connected to the input end of the grid-connected detection and control device, and the other end of the first voltage divider module 10 is connected to the MCU module 13.

[0028] One end of the second voltage divider module 11 is connected to the output end of the grid-connected detection and control device, and the other end of the second voltage divider module is connected to the MCU module 13.

[0029] The first voltage divider module 10 is used to sample the voltage at the input terminal by voltage division to obtain a first voltage signal, and then sends the first voltage signal to the MCU module 13. Specifically, the first voltage divider module 10 can convert the high-voltage signal at the input terminal into a low-voltage signal suitable for acquisition by the MCU module 13. The first voltage divider module 10 can employ a resistor voltage divider circuit, with a division ratio of, for example, 1000:1, meaning it converts the 220V AC voltage at the input terminal into a low-voltage signal of 0.22V. Simultaneously, when acquiring the voltage signal at the input terminal, the first voltage divider module 10 can also detect the zero-crossing point of the voltage signal, thereby outputting the first voltage signal.

[0030] The second voltage divider module 11 is used to sample the voltage at the output terminal by voltage division to obtain a second voltage signal, and then sends the second voltage signal to the MCU module 13. Specifically, the second voltage divider module 11 can convert the high-voltage signal at the output terminal into a low-voltage signal suitable for acquisition by the MCU module 13. The second voltage divider module 11 can employ a resistor voltage divider circuit, with a division ratio of, for example, 1000:1, meaning it converts the 220V AC voltage at the output terminal into a low-voltage signal of 0.22V. Simultaneously, when acquiring the voltage signal at the output terminal, the second voltage divider module 11 can also detect the zero-crossing point of the voltage signal, thereby outputting the second voltage signal.

[0031] The MCU module 13 determines the voltage difference and phase difference between the input and output terminals based on the first voltage signal and the second voltage signal, and determines whether to output a grid connection command based on the voltage difference and phase difference.

[0032] Optionally, the MCU module 13 receives two conditioned voltage signals from the input and output terminals, namely, a first voltage signal and a second voltage signal. The first voltage signal represents the timing and amplitude characteristics of the voltage at the input terminal, i.e., the grid side, while the second voltage signal represents the timing and amplitude characteristics of the voltage at the inverter output terminal. The first and second voltage signals have a defined physical correspondence on the electrical path and are both synchronously sampled from the same reference ground, satisfying the consistency requirement for phase comparison.

[0033] Optionally, the MCU module 13 can determine whether the grid connection adaptation conditions are met based on the voltage difference and phase difference. If they are met, the MCU module 13 can generate and output a grid connection command. This grid connection command can drive the actuator to perform the grid connection operation and can send a grid connection notification to the inverter through the communication module, which can communicate with the MCU module 13.

[0034] In this embodiment, the voltage at the input terminal is sampled by a first voltage divider module to obtain a first voltage signal, which is then sent to the MCU module. Similarly, the voltage at the output terminal is sampled by a second voltage divider module to obtain a second voltage signal, which is also sent to the MCU module. The MCU module then determines the voltage difference and phase difference between the input and output terminals based on the first and second voltage signals, and determines whether to output a grid connection command based on these differences. This allows for grid connection data acquisition and control within the circuit breaker, solving the problem of inverters needing to collect grid-side parameters independently and incurring heavy hardware burdens in existing technologies. By having the MCU module in the circuit breaker autonomously determine grid connection conditions and directly control the circuit breaker's operation, the grid connection response time can be shortened, resulting in smaller voltage and phase differences at the moment of grid connection, reducing the impact on the grid, and improving grid connection quality and grid stability.

[0035] Figure 2 This is a schematic diagram of the structure of the second grid-connected detection and control device provided in the embodiments of this application, as shown below. Figure 2 As shown, the grid connection detection and control device may also include a first metering module 14 and a second metering module 15.

[0036] One end of the first metering module 14 is connected to the input terminal of the grid-connected detection and control device, and the other end of the first metering module 14 is connected to the MCU module 13. Specifically, the first metering module 14 includes a bidirectional electrical interface. The input terminal of the first metering module 14 is electrically connected to the input terminal of the grid-connected detection and control device for directly coupling the AC signal from the input terminal. The output terminal of the first metering module 14 establishes a signal path with the MCU module 13 for unidirectionally transmitting the acquired first electrical signal to the MCU module 13.

[0037] One end of the second metering module 15 is connected to the output terminal of the grid-connected detection and control device, and the other end of the second metering module 15 is connected to the MCU module. Specifically, the second metering module 15 includes a bidirectional electrical interface. The input terminal of the second metering module 15 is electrically connected to the output terminal of the grid-connected detection and control device for directly coupling the AC signal from the output terminal. The output terminal of the second metering module 15 establishes a parallel and time-synchronized signal path with the MCU module 13, which is used to unidirectionally transmit the acquired second electrical signal to the MCU module 13.

[0038] The first metering module 14 is used to acquire a first electrical signal at the input terminal and send the first electrical signal to the MCU module. This first electrical signal may include the voltage and current at the input terminal. Specifically, a voltage transformer and a current transformer can be configured in the first metering module 14 to acquire the voltage and current at the input terminal. A resistor divider circuit can also be used in the first metering module 14 to implement the voltage acquisition function.

[0039] The second metering module 15 is used to acquire a second electrical signal at the output terminal and send the second electrical signal to the MCU module 13. This second electrical signal may include the voltage and current at the output terminal. Specifically, a voltage transformer and a current transformer can be configured in the second metering module 15 to acquire the voltage and current at the output terminal. A resistor divider circuit can also be used in the second metering module 15 to implement the voltage acquisition function.

[0040] MCU module 13 is also used to measure the electrical signal between the input terminal and the output terminal based on the first electrical signal and the second electrical signal. For example, it can calculate the voltage difference, current difference, power flow direction, phase angle difference, impedance characteristics, etc. between the input terminal and the output terminal.

[0041] The first and second electrical signals maintain synchronization in terms of sampling time, sampling rate, phase reference, and amplitude calibration. This synchronization is driven by the same clock source or guaranteed by a hardware triggering mechanism, thereby ensuring physical comparability and engineering reliability when the subsequent MCU module 13 performs cross-port comparison operations on the first and second electrical signals.

[0042] In this embodiment, by setting a metering module in the grid-connected detection device, the metering functions of current, voltage, and power are realized. This is independently distinguished from the voltage divider module mentioned above, with a clear division of labor between the two modules and a simple design. Furthermore, the MCU module provides the metered data to the inverter, reducing the burden on the inverter to collect grid-side parameters on its own, and lowering the inverter's hardware cost and design complexity.

[0043] Optionally, the first metering module 14 may include a first voltage acquisition unit, a first phase acquisition unit, and a first metering unit.

[0044] Optionally, one end of the first voltage acquisition unit, one end of the first phase acquisition unit, and one end of the first metering unit are all connected to the input terminal, and the other ends of the first voltage acquisition unit, the first phase acquisition unit, and the first metering unit are all connected to the MCU module 13. Specifically, the first voltage acquisition unit acquires the first voltage at the input terminal and sends it to the MCU module. The first phase acquisition unit acquires the first phase at the input terminal and sends it to the MCU module 13. The first metering unit acquires the first electrical signal at the input terminal and sends it to the MCU module 13. Specifically, the first metering unit can acquire the voltage at the input terminal using a voltage transformer or a resistor divider. Then, the metering chip performs analog-to-digital conversion on the sampled voltage signal, calculates the effective voltage value using digital filtering and an FFT algorithm, and outputs the effective voltage value to the MCU module.

[0045] Optionally, the second metering module 15 may include a second voltage acquisition unit, a second phase acquisition unit, and a second metering unit.

[0046] Optionally, one end of the second voltage acquisition unit, one end of the second phase acquisition unit, and one end of the second metering unit are all connected to the output terminal, and the other ends of the second voltage acquisition unit, the second phase acquisition unit, and the second metering unit are all connected to the MCU module 13. Specifically, the second voltage acquisition unit is used to acquire the second voltage at the output terminal and send it to the MCU module 13. The second phase acquisition unit is used to acquire the second phase at the output terminal and send it to the MCU module 13. The second metering unit is used to acquire the second electrical signal at the output terminal and send it to the MCU module 13.

[0047] In this embodiment, the metering module is functionally expanded to include voltage and phase acquisition and metering functions, thereby eliminating the need for separate voltage divider and grid connection detection modules, reducing hardware costs, and simplifying the system architecture.

[0048] Optionally, the MCU module 13 is specifically configured to: determine the zero-crossing times of the first voltage signal and the second voltage signal through the input capture function, thereby obtaining the first rising zero-crossing point corresponding to the first voltage signal and the second rising zero-crossing point corresponding to the second voltage signal. Then, based on the first and second rising zero-crossing points, determine the phase difference between the input and output terminals. Specifically, calculate the time difference between the first and second rising zero-crossing points to obtain the phase difference.

[0049] Specifically, MCU module 13 is used to determine the voltage difference between the input terminal and the output terminal based on the first effective voltage value corresponding to the first voltage signal and the second effective voltage value corresponding to the second voltage signal. Specifically, it calculates the difference between the first effective voltage value corresponding to the first voltage signal and the second effective voltage value corresponding to the second voltage signal to obtain the voltage difference.

[0050] Accurately obtaining the phase difference between the voltage signals at the input and output ends is a key prerequisite for judging line loss, identifying electricity theft, achieving synchronous sampling, and evaluating power supply quality.

[0051] Optionally, the MCU module 13 is specifically used for: The voltage difference and phase difference are sent to the inverter so that the inverter can output a grid connection instruction to the MCU module 13 based on the phase difference and voltage difference. After receiving the grid connection instruction sent by the inverter, the MCU module 13 outputs a grid connection instruction according to the grid connection instruction, that is, controls the actuator to perform the grid connection operation.

[0052] Optionally, the MCU module 13 is specifically used to: determine whether the phase difference is less than a phase threshold and whether the voltage difference is less than a voltage threshold; if the phase difference is less than the phase threshold and the voltage difference is less than the voltage threshold, then output a grid connection command. The phase threshold and voltage threshold can be set according to actual needs. If the phase difference is greater than or equal to the phase threshold, or the voltage difference is greater than or equal to the voltage threshold, then no grid connection command is output.

[0053] Optionally, the grid-connected detection and control device may also include a power supply module 16 and a low-voltage energy storage module 17.

[0054] One end of the power module 16 is connected to the input terminal, and the other end of the power module 16 is connected to one end of the low-voltage energy storage module 17 and the MCU module 13 respectively. The other end of the low-voltage energy storage module 17 is connected to the magnetic flux trip unit 18.

[0055] The power module 16 is used to supply power to the MCU module 13; the low-voltage energy storage module 17 is used to charge when the voltage is normal; when the voltage is abnormal, the low-voltage energy storage module 17 discharges and drives the magnetic flux trip unit to perform a tripping operation.

[0056] The power module 16 is an adaptive wide-range power-taking module deeply coupled to the working logic of the grid-connected detection device. One end of the power module 16 is directly connected to the input terminal of the grid-connected detection device, i.e., the high-voltage AC input terminal on the grid side. The other end outputs a regulated or isolated DC voltage to supply the MCU module 13. The power module 16 can integrate a wide-input-range active rectifier unit, an ultra-low leakage inductance high-frequency isolation transformer, and dual-path redundant voltage regulation. The input of the power module 16 is directly taken from the input terminal.

[0057] The power module 16 may include safety components, an AC / DC conversion unit, and a DC / DC conversion unit. The safety components, which may be located at the input of the power module 16, include a varistor, a fuse, and a common-mode inductor, providing surge protection, overcurrent protection, and EMI filtering for the input power supply. The AC / DC conversion unit may employ a flyback switching power supply topology and may use a PWM control chip. The DC / DC conversion unit may include two buck converters: the first converts DC 12V to DC 5V with an output current of 2A, powering the metering and communication modules; the second converts DC 12V to DC 3.3V with an output current of 1A, powering the MCU module 13. The DC / DC conversion unit uses synchronous rectification technology, achieving a conversion efficiency greater than 90%.

[0058] Optionally, the actuator 19 is used to perform the closing and opening actions of the circuit breaker, and includes a motor drive circuit, a motor, a low-voltage energy storage capacitor, and a flux trip unit. The actuator can be connected to an MCU module, which controls the conduction state of the actuator by outputting grid connection and disconnection commands to realize the forward rotation, reverse rotation, and stop of the motor. When the MCU module outputs a grid connection command, the motor rotates forward, driving the circuit breaker contacts to close; when the MCU module outputs a disconnection command, the motor reverses, driving the circuit breaker contacts to open.

[0059] Figure 3 This is a flowchart illustrating a grid-connected detection and control method provided in an embodiment of this application, as shown below. Figure 3 As shown, this method is applied to the MCU module in the grid-connected detection and control device in the aforementioned specific embodiment. The method includes: S101. Obtain the first voltage signal sent by the first voltage divider module and the second voltage signal sent by the second voltage divider module.

[0060] The first voltage signal represents the timing and amplitude characteristics of the voltage at the input terminal, i.e., the grid side, while the second voltage signal represents the timing and amplitude characteristics of the voltage at the inverter output terminal. The first and second voltage signals have a definite physical correspondence on the electrical path and are both synchronously sampled from the same reference ground system, satisfying the consistency requirement for phase comparison.

[0061] Optionally, the first voltage signal can also be obtained from the first metering module, and the second voltage signal can also be obtained from the second metering module.

[0062] S102. Based on the first voltage signal and the second voltage signal, determine the voltage difference and phase difference between the input terminal and the output terminal, and determine whether to output a grid connection command based on the voltage difference and phase difference.

[0063] Optionally, the MCU module can use a preset method to determine the voltage difference and phase difference between the input and output terminals based on the first voltage signal and the second voltage signal, and determine whether to output a grid connection command based on the voltage difference and phase difference.

[0064] Optionally, determining the voltage difference and phase difference between the input and output terminals based on the first voltage signal and the second voltage signal in S102 above may include: Specifically, the MCU module can determine the zero-crossing times of the first voltage signal and the second voltage signal through the input capture function, thereby obtaining the first rising zero-crossing point corresponding to the first voltage signal and the second rising zero-crossing point corresponding to the second voltage signal; then, based on the first rising zero-crossing point and the second rising zero-crossing point, the phase difference between the input terminal and the output terminal is determined; then, based on the first effective voltage value corresponding to the first voltage signal and the second effective voltage value corresponding to the second voltage signal, the voltage difference between the input terminal and the output terminal is determined.

[0065] Optionally, the MCU module can send the voltage difference and phase difference to the inverter, so that the inverter can output a grid connection instruction to the MCU module based on the phase difference and voltage difference. After receiving the grid connection instruction sent by the inverter, the MCU module outputs a grid connection instruction according to the grid connection instruction.

[0066] Optionally, the MCU module can determine whether the phase difference is less than a phase threshold and whether the voltage difference is less than a voltage threshold.

[0067] If the phase difference is less than the phase threshold and the voltage difference is less than the voltage threshold, then a grid connection command is output.

[0068] If the phase difference is greater than or equal to the phase threshold, or the voltage difference is greater than or equal to the voltage threshold, then no grid connection command will be output.

[0069] This application also provides a circuit breaker, including the grid connection detection and control device described in the foregoing specific embodiments.

[0070] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems and devices described above can be referred to the corresponding processes in the method embodiments, and will not be repeated here. In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed mutual coupling or direct coupling or communication connection can be through some communication interfaces; the indirect coupling or communication connection of devices or modules can be electrical, mechanical, or other forms.

[0071] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. If the functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes: USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, optical disks, and other media capable of storing program code.

[0072] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any changes 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.

Claims

1. A grid-connected detection and control device, characterized in that, include: The first voltage divider module, the second voltage divider module, and the MCU module; One end of the first voltage divider module is connected to the input terminal of the grid-connected detection and control device, and the other end of the first voltage divider module is connected to the MCU module. One end of the second voltage divider module is connected to the output terminal of the grid-connected detection and control device, and the other end of the second voltage divider module is connected to the MCU module; The first voltage divider module is used to perform voltage divider sampling on the voltage at the input terminal to obtain a first voltage signal, and send the first voltage signal to the MCU module; The second voltage divider module is used to perform voltage divider sampling on the voltage at the output terminal to obtain a second voltage signal, and then send the second voltage signal to the MCU module; The MCU module determines the voltage difference and phase difference between the input terminal and the output terminal based on the first voltage signal and the second voltage signal, and determines whether to output a grid connection command based on the voltage difference and phase difference.

2. The grid connection detection and control device according to claim 1, characterized in that, Also includes: The first metering module and the second metering module; One end of the first metering module is connected to the input end of the grid-connected detection and control device, and the other end of the first metering module is connected to the MCU module. One end of the second metering module is connected to the output end of the grid-connected detection and control device, and the other end of the second metering module is connected to the MCU module; The first metering module is used to collect the first electrical signal at the incoming end and send the first electrical signal to the MCU module; the second metering module is used to collect the second electrical signal at the outgoing end and send the second electrical signal to the MCU module. The MCU module is also used to measure the electrical signal between the input terminal and the output terminal based on the first electrical signal and the second electrical signal.

3. The grid connection detection and control device according to claim 2, characterized in that, The first metering module includes: a first voltage acquisition unit, a first phase acquisition unit, and a first metering unit; One end of the first voltage acquisition unit, one end of the first phase acquisition unit, and one end of the first metering unit are all connected to the input terminal; the other end of the first voltage acquisition unit, the other end of the first phase acquisition unit, and the other end of the first metering unit are all connected to the MCU module. The first voltage acquisition unit is used to acquire the first voltage at the input terminal and send the first voltage to the MCU module; The first phase acquisition unit is used to acquire the first phase of the incoming line and send the first phase to the MCU module; The first metering unit is used to collect the first electrical signal at the incoming line and send the first electrical signal to the MCU module.

4. The grid connection detection and control device according to claim 2, characterized in that, The second metering module includes: a second voltage acquisition unit, a second phase acquisition unit, and a second metering unit; The second voltage acquisition unit, the second phase acquisition unit, and the second metering unit are all connected to the MCU module; The second voltage acquisition unit is used to acquire the second voltage at the output terminal and send the second voltage to the MCU module; The second phase acquisition unit is used to acquire the second phase of the outgoing terminal and send the second phase to the MCU module; The second metering unit is used to collect the second electrical signal at the output terminal and send the second electrical signal to the MCU module.

5. The grid connection detection and control device according to claim 1, characterized in that, The MCU module is specifically used to: determine the zero-crossing times of the first voltage signal and the second voltage signal through the input capture function, and obtain the first rising zero-crossing point corresponding to the first voltage signal and the second rising zero-crossing point corresponding to the second voltage signal; The phase difference between the input terminal and the output terminal is determined based on the first rising zero-crossing point and the second rising zero-crossing point. The voltage difference between the input terminal and the output terminal is determined based on the first effective voltage value corresponding to the first voltage signal and the second effective voltage value corresponding to the second voltage signal.

6. The grid connection detection and control device according to claim 1, characterized in that, The MCU module is specifically used for: The voltage difference and phase difference are sent to the inverter so that the inverter can output a grid connection instruction to the MCU module based on the phase difference and voltage difference. After receiving the grid connection instruction sent by the inverter, the MCU module outputs a grid connection command based on the grid connection instruction.

7. The grid connection detection and control device according to claim 1, characterized in that, The MCU module is specifically used to: determine whether the phase difference is less than a phase threshold and whether the voltage difference is less than a voltage threshold; If the phase difference is less than the phase threshold and the voltage difference is less than the voltage threshold, then a grid connection command is output.

8. The grid connection detection and control device according to claim 1, characterized in that, Also includes: Power supply module, low-voltage energy storage module; One end of the power module is connected to the input terminal, and the other end of the power module is connected to one end of the low-voltage energy storage module and the MCU module respectively. The other end of the low-voltage energy storage module is connected to the magnetic flux trip unit. The power module is used to supply power to the MCU module; the low-voltage energy storage module is used to charge when the voltage is normal; when the voltage is abnormal, the low-voltage energy storage module discharges and drives the magnetic flux trip unit to perform a tripping operation.

9. A grid connection detection method, characterized in that, The method, applied to the MCU module in the grid-connected detection and control device according to any one of claims 1-8, comprises: Obtain the first voltage signal sent by the first voltage divider module; Obtain the second voltage signal sent by the second voltage divider module; Based on the first voltage signal and the second voltage signal, the voltage difference and phase difference between the input terminal and the output terminal are determined, and whether to output a grid connection command is determined based on the voltage difference and phase difference.

10. A circuit breaker, characterized in that, Includes the grid connection detection and control device as described in any one of claims 1-8.

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