Method and apparatus for determining state of grid-connected power generation, and computer device

Abstract

A method and apparatus for determining the state of grid-connected power generation, and a computer device. The method is applied to a grid-connected power generation system. The grid-connected power generation system comprises a current-sampling apparatus (120) and a grid-connected electric power converter (110) which are connected to one another; the current-sampling apparatus (120) is connected to an output end of a power grid side, and measures a current on the basis of the principle of electromagnetic induction. The method comprises: after the current-sampling apparatus (120) is powered on, acquiring a current value collected by the current-sampling apparatus (120) (S100); adjusting an output current outputted by the grid-connected electric power converter (110) (S200); controlling the current-sampling apparatus (120) to collect a current again so as to obtain a current value (S300); and comparing the current value collected before the output current was adjusted and the current value collected after the output current was adjusted so as to determine the state of grid-connected power generation (S400). Use of the present method can improve the safety of the process of determining the state of grid-connected power generation.

Description

Methods, devices, and computer equipment for determining grid-connected power generation status

[0001] Related applications

[0002] This application claims priority to Chinese patent application filed on November 1, 2024, application number 2024115468107, entitled "Method, Apparatus and Computer Equipment for Determining Grid-Connected Power Generation Status", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of new energy technology, and in particular to a method, apparatus, computer equipment, computer-readable storage medium, and computer program product for determining grid-connected power generation status. Background Technology

[0004] With the rapid development of new energy technologies, distributed power generation systems such as balcony photovoltaics and residential photovoltaics have been widely used. However, in order to improve the utilization rate of new energy power generation, it is necessary to ensure self-consumption as much as possible and avoid feeding power back to the public grid. Therefore, how to prevent grid-connected power generation systems from feeding back into the grid has become one of the key issues of concern.

[0005] In traditional solutions, smart current transformers installed at the inlet of the household typically sample the mains current and voltage. By determining the phase relationship between the mains voltage and current, it is possible to determine whether the grid-connected power generation system is feeding power back into the public grid (reverse flow).

[0006] However, the above solution requires disconnecting the circuit breaker in the sampling device and connecting the sampling line to the household terminal during the installation process. This process involves operating high-voltage electricity, resulting in low safety of the above method. Summary of the Invention

[0007] According to various embodiments of this application, a method, apparatus, computer device, computer-readable storage medium, and computer program product for determining grid-connected power generation status are provided.

[0008] In a first aspect, this application provides a method for determining the state of grid-connected power generation, applied to a grid-connected power generation system. The grid-connected power generation system includes a current sampling device and a grid-connected power converter connected to each other. The current sampling device is connected to the output terminal of the grid side and measures the current based on the principle of electromagnetic induction, including:

[0009] After the current sampling device is powered on, the current value collected by the current sampling device is acquired.

[0010] Adjust the output current of the grid-connected power converter;

[0011] The current sampling device is controlled to collect the current again to obtain the current value;

[0012] The grid-connected power generation status is determined by comparing the current value collected before the output current adjustment with the current value collected after the output current adjustment.

[0013] In some embodiments, adjusting the output current of the grid-connected power converter includes:

[0014] Reduce the output current of the grid-connected power converter;

[0015] The step of comparing the current value collected before the output current adjustment with the current value collected after the output current adjustment to determine the grid-connected power generation status includes:

[0016] If the current value collected before the output current decreases is greater than the current value collected after the output current decreases, the grid-connected power generation state is determined to be a power feeding state, and the process returns to the step of reducing the output current of the grid-connected power converter until the current value collected before the output current decreases is less than or equal to the current value collected after the output current decreases.

[0017] In some embodiments, comparing the current value collected before the output current adjustment with the current value collected after the output current adjustment to determine the grid-connected power generation status includes:

[0018] If the current value collected before the output current decreases is less than the current value collected after the output current decreases, the grid-connected power generation state is determined to be the power consumption state.

[0019] In some embodiments, after determining that the grid-connected power generation state is an electricity consumption state, the method further includes:

[0020] Increase the output current of the grid-connected power converter;

[0021] Returning to the step of controlling the current sampling device to collect the current again, until the current value collected before the output current increases is less than or equal to the current value collected after the output current increases.

[0022] In some embodiments, increasing the output current of the grid-connected power converter includes:

[0023] The output current adjustment value is determined based on the difference between the current value collected before the output current decreases or increases and the current value collected after the output current decreases or increases.

[0024] The output current of the grid-connected power converter is increased according to the output current adjustment value.

[0025] In some embodiments, the method further includes:

[0026] Compare the current value difference with a preset current value difference threshold;

[0027] If the difference in current values ​​exceeds the preset threshold for the difference in current values, a preset alarm mechanism is triggered.

[0028] In some embodiments, the current sampling device is inserted into the live or neutral wire at the entrance of the household.

[0029] In some embodiments, the current sampling device includes a main control module, a sampling coil, and a power supply coil, wherein the sampling coil measures the current based on the principle of electromagnetic induction.

[0030] In some embodiments, the power supply circuit of the current sampling device includes a capacitor or a rechargeable battery.

[0031] In some embodiments, the current sampling device is a smart transformer.

[0032] In some embodiments, the grid-connected power converter is a grid-connected inverter.

[0033] Secondly, this application also provides a grid-connected power generation status determination device, deployed in a grid-connected power generation system. The grid-connected power generation system includes an interconnected current sampling device and a grid-connected power converter. The current sampling device is connected to the output terminal of the grid side and measures the current based on the principle of electromagnetic induction, including:

[0034] The first sampling module is used to acquire the current value collected by the current sampling device after the current sampling device is powered on.

[0035] A current adjustment module is used to adjust the output current of the grid-connected power converter;

[0036] The second sampling module is used to control the current sampling device to collect the current again and obtain the current value;

[0037] The status judgment module is used to compare the current value collected before the output current adjustment with the current value collected after the output current adjustment to determine the grid-connected power generation status.

[0038] Thirdly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in any of the above embodiments of the grid-connected power generation status determination method.

[0039] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps in any of the above embodiments of the grid-connected power generation state determination method.

[0040] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, implements the steps in the above embodiments of the grid-connected power generation state determination method. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the disclosed drawings without creative effort.

[0042] Figure 1 shows the application environment of the grid-connected power generation status determination method in some embodiments;

[0043] Figure 2 is a flowchart illustrating the grid-connected power generation status determination method in some embodiments;

[0044] Figure 3 is a flowchart illustrating the steps for adjusting the power supply state in some embodiments;

[0045] Figure 4 is a flowchart illustrating the steps for adjusting the power consumption status in some other embodiments;

[0046] Figure 5 is a flowchart illustrating the grid-connected power generation status determination method in a detailed embodiment;

[0047] Figure 6 is a structural block diagram of the grid-connected power generation status determination device in some embodiments;

[0048] Figure 7 is an internal structure diagram of a computer device in some embodiments. Detailed Implementation

[0049] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0050] The grid-connected power generation status determination method provided in this application embodiment can be applied to the application environment shown in Figure 1. The local load 130 has two power sources: the public power grid 140 supplies mains current to the local load 130, and the grid-connected power generation system converts the electrical energy generated by the new energy facilities into electrical energy that can be directly used by the local load 130 through a grid-connected power converter 110, thereby supplying power to the local load 130. The grid-connected power converter 110 can be a grid-connected inverter. The current sampling device 120 can include a main control module and a sampling coil. The sampling coil collects the mains current on the public power grid 140 side's incoming line based on the principle of electromagnetic induction, and performs high and low voltage isolation, etc. The main control module is used to perform operations such as controlling the sampling coil to sample and sending control commands to the grid-connected power converter 110 to adjust its output current. The current sampling device 120 can be an open-type intelligent current transformer, which can be directly inserted into the L / N (Live / Neutral) line at the incoming end, facilitating user operation and assembly. It should be noted that, unless otherwise specified, the grid-connected power converters (or grid-connected inverters) mentioned in the embodiments of this application are all connected to the clean energy power generation system, and the output current of the grid-connected power converter (or grid-connected converter) also refers to the current generated by the clean energy power generation system and output through the grid-connected power converter (or grid-connected converter).

[0051] Specifically, after the current sampling device 120 is powered on, the sampling coil collects the current value and sends it to the main control module of the current sampling device 120. The main control module sends a control command to the grid-connected power converter 110 via wireless communication, so that the grid-connected power converter 110 adjusts the output current and controls the CT coil to collect the current value again. The main control module compares the current value collected before the output current adjustment with the current value collected after the output current adjustment to determine the grid-connected power generation status.

[0052] It should be noted that the main control module in the above scheme can be integrated inside the current sampling device 120 or exist independently of the current sampling device 120. It interacts with the acquisition coil and grid-connected power converter 110 inside the current sampling device 120 via wireless or wired communication. Wired communication can be based on RS485, RS232, LAN (Local Area Network), or CAN (Controller Area Network) communication protocols; no limitation is made here. In addition to the sampling coil, the current sampling device 120 also includes a power supply coil. The sampling coil and the power supply coil can be two independent coils or the same coil. When the sampling coil and the power supply coil are two independent coils, the current induced by the power supply coil will not affect the current induced by the sampling coil, thus improving the accuracy of the current value acquired by the sampling coil. When the sampling coil and the power supply coil are the same coil, after the coil senses the current, it will send the sensed current to the power supply circuit and the sampling circuit respectively. The power supply circuit supplies power to the sampling circuit and the main control module. At this time, it is necessary to calculate and exclude the power supply current that supplies power to the intelligent current transformer 105 to obtain the current value collected by the sampling circuit.

[0053] Furthermore, because the mains current output from the public grid 140 varies significantly depending on the output current of the grid-connected inverter and the power consumption of the local load 130, a capacitor or rechargeable battery is added to the power supply circuit of the current sampling device 120 for energy storage to ensure stable internal power supply. The sampling circuit amplifies, filters, and protects the signal before sending it to the main control module, such as the ADC (Analog-to-Digital Converter) of the MCU (Microcontroller Unit) for processing. The MCU is responsible for sampling calculations, control algorithm execution, and external communication. External communication mainly involves data and control command interaction with the grid-connected inverter, but it can also communicate with other home monitoring systems. Communication methods include wireless modules and wired communication interfaces.

[0054] In an exemplary embodiment, as shown in FIG2, a method for determining the grid-connected power generation status is provided. This method is applied to a grid-connected power generation system, which includes a current sampling device and a grid-connected power converter connected to each other. The current sampling device is connected to the output terminal of the grid side and measures the current based on the principle of electromagnetic induction. Taking the main control module inside the current sampling device 120 in FIG1 as an example, the method includes the following steps:

[0055] S100 acquires the current value collected by the current sampling device after the current sampling device is powered on.

[0056] The current sampling device is a device used to measure current. In this application, it is installed at the output terminal on the power grid side. It measures the current based on the principle of electromagnetic induction. The principle of electromagnetic induction states that when a conductor moves in a magnetic field or the magnetic field changes around the conductor, an induced electromotive force is generated in the conductor, thereby producing a current. The current sampling device includes, but is not limited to, intelligent current transformers or Hall effect sensors. The following explanation uses an intelligent current transformer as an example.

[0057] For example, the smart transformer measures the grid output current by interacting with the magnetic field formed by the current at the grid output terminal through its built-in sampling coil. When the smart transformer is powered on, the main control module inside the smart transformer first establishes communication with the grid-connected power converter (such as a grid-connected inverter), which can be wireless or wired communication. At the same time, it starts working and measures the current at the grid-side output terminal, and sends the collected current value to the main control module integrated inside the smart transformer.

[0058] S200, adjusts the output current of the grid-connected power converter.

[0059] A grid-connected power converter is a device that converts direct current (DC) to alternating current (AC) to supply power to local loads. In this application, a grid-connected inverter is used as an example for explanation. Output current refers to the current output by the grid-connected inverter that can be used by the local load; that is, the electrical energy generated by clean energy (such as solar power) and output through the grid-connected inverter. In practical applications, the output current may flow into the local load or local energy storage device, thus supplying power to the local load or local energy storage device. The output current may also flow into the public power grid; in this case, the current flowing into the public power grid can also be called the grid-connected current. Furthermore, the public power grid can also output current to the local load or local energy storage device through a grid-connected inverter connected to the public power grid, thereby supplying power to the local load or local energy storage device.

[0060] Specifically, grid-connected inverters are used in solar photovoltaic power generation systems or wind power generation systems. These distributed power generation devices typically generate direct current (DC), and the grid-connected inverter converts this DC into alternating current (AC) and delivers the current to the local load.

[0061] For example, the main control module of the smart transformer sends control commands to the grid-connected inverter via wireless or wired communication to adjust the output parameters of the grid-connected inverter. For example, it adjusts the duty cycle of the output current of the grid-connected inverter through PWM (Pulse Width Modulation) so that the magnitude of the output current of the grid-connected inverter changes.

[0062] S300 controls the current sampling device to collect the current again and obtain the current value.

[0063] Following the steps above, after the output current of the grid-connected inverter changes, the main control unit of the smart transformer controls the sampling coil to collect the current again based on the principle of electromagnetic induction, and obtain the current value.

[0064] S400 compares the current value collected before the output current adjustment with the current value collected after the output current adjustment to determine the grid-connected power generation status.

[0065] The grid-connected generation status can be used to characterize the supply status of electrical energy generated by photovoltaic (PV) equipment or other new energy equipment, including power consumption status and power feeding status. For example, considering the working nature of grid-connected inverters, when the electrical energy generated by PV or other new energy sources is preferentially supplied to local loads after passing through the grid-connected inverter, under conditions of particularly good sunlight, other favorable conditions for new energy generation, or relatively small local loads, the electrical energy output by the grid-connected inverter may exceed the demand of the local load and be fed into the public grid. This is called reverse current (part of the output current of the grid-connected inverter is input into the public grid, and the current flowing into the public grid is the grid-connected current), also known as the power feeding status. For safety reasons, this situation should be avoided as much as possible. However, when environmental conditions are unfavorable for PV or other new energy generation, or when the local load is relatively large, the output current output by the grid-connected inverter is entirely supplied to the local load, and there is no reverse current flowing into the public grid. In this case, the grid-connected generation status is the power consumption status.

[0066] Since the process of adjusting the output current and the smart transformer collecting the current value again is very short, it can be assumed that the local load size remains unchanged within such a short time. After the output current is adjusted, the current value of the grid side collected by the smart transformer will also change. Based on this change, the grid-connected power generation status can be determined without collecting the voltage on the circuit line, eliminating the need for high-voltage operation of the voltage sampling line and improving the safety of the operation process.

[0067] For example, if the output current of the grid-connected inverter increases, and if there is no reverse current phenomenon in the grid-connected system (grid-connected generation state is power consumption state), and the local load is assumed to remain unchanged, the output current on the grid side collected by the smart transformer should decrease accordingly. Conversely, if reverse current phenomenon occurs in the grid-connected system (grid-connected generation state is power feeding state), the output current on the grid side collected by the smart transformer should increase accordingly. Therefore, by comparing the current value collected before the output current adjustment with the current value collected after the output current adjustment, the grid-connected generation state of the grid-connected system can be determined.

[0068] The above-described method for determining grid-connected power generation status involves acquiring the current value collected by the current sampling device after it is powered on. Then, the grid-connected power converter is controlled to adjust its output current, and the current sampling device is controlled to collect the current value again. Finally, the current value collected before the output current adjustment is compared with the current value collected after the adjustment to determine the grid-connected power generation status. Unlike traditional methods, this method eliminates the need for voltage sampling; it only requires current sampling. Combined with adjustments to the output current of the grid-connected power converter, the grid-connected power generation status can be quickly determined. Furthermore, the current sampling device in this method measures current based on the principle of electromagnetic induction, thus eliminating the need to disconnect the circuit breaker in the sampling device and connect the sampling line to the household terminal to sample the voltage, thereby improving the safety of the process for determining the grid-connected power generation status.

[0069] Furthermore, adjusting the output current of the grid-connected inverter can be done by increasing or decreasing the output current. In an exemplary embodiment, as shown in Figure 3, S200 includes:

[0070] S210 reduces the output current of the grid-connected power converter.

[0071] S400 includes: S410, which compares the current value collected before the output current decreases with the current value collected after the output current decreases.

[0072] S420: If the current value collected before the output current decreases is greater than the current value collected after the output current decreases, the grid-connected power generation state is determined to be a power feeding state, and the process returns to S210 until the current value collected before the output current decreases is less than or equal to the current value collected after the output current decreases.

[0073] In this context, "feeding state" refers to the process by which the grid-connected inverter transmits electrical energy to the public power grid. Continuing with the previous embodiment, taking the reduction of the output current of the grid-connected inverter as an example, if the current value collected by the smart transformer after reducing the output current is less than the current value collected before the reduction, it indicates that the grid-connected power generation system connected to the inverter is in a high-level power generation state, and the generated electrical energy exceeds the electrical energy required by the local load. Therefore, there is excess electrical energy fed back to the public power grid, and the grid-connected power generation state is a feeding state. Similarly, if the current value collected before the output current increases is less than the current value collected after the output current increases, the grid-connected power generation state is determined to be a feeding state.

[0074] It should be noted that the process of determining the grid-connected power generation status is very brief. Therefore, smart transformers need to have the characteristics of fast response and high sensitivity to reduce the impact of noise or data delay during the measurement process.

[0075] Furthermore, upon detecting that the grid-connected power generation system is in a feed-in state, the main control module of the smart transformer will continue to control the grid-connected inverter to reduce the output current, thereby reducing the feed-in current value. After each reduction in output current, the smart transformer will collect a new current value and compare it with the current value before the output current reduction. The process continues until the current value before the reduction is less than or equal to the current value after the reduction. This indicates that the grid-connected power generation system has achieved zero feed-in, and the system has reached or is close to achieving a balance between local load demand and power generation output. At this point, the reduction of the output current will cease.

[0076] In addition, during the process of reducing the output current, it is necessary to precisely control the magnitude and speed of the current reduction. This is because too fast or too large an adjustment may cause power fluctuations, while too slow or too small an adjustment may cause the grid-connected power generation system to be in a power-fed state for a long time, which may pose certain safety hazards. Therefore, a suitable adjustment range can be preset, and the output current can be adjusted according to the preset adjustment range.

[0077] In this embodiment, by first controlling the output current of the grid-connected inverter to decrease, and combining this with the current values ​​collected by the intelligent current transformer before and after the output current decrease, the state of the grid-connected power generation system can be effectively determined without setting a voltage sampling line to sample the voltage, thus improving the reliability and safety of the process of determining the grid-connected power generation state. Furthermore, by using cyclic control to reduce the feed current value in this embodiment, the situation of excessively reducing the output current can be effectively reduced, while simultaneously bringing the grid-connected power generation system to or near a zero-feed state as quickly as possible.

[0078] Following the above embodiments, in an exemplary embodiment, as shown in FIG4, S400 includes:

[0079] S430 determines the adjustment method of the previous output current and compares the current value collected before the output current adjustment with the current value collected after the output current adjustment.

[0080] S440 determines the grid-connected power generation state as the power consumption state if the current value collected before the output current decreases is less than the current value collected after the output current decreases, or if the current value collected before the output current increases is greater than the current value collected after the output current increases.

[0081] Following the above embodiments, the power consumption status refers to the state in which the public power grid and the grid-connected power generation system jointly supply power to the local load. When the output current of the grid-connected inverter is insufficient to meet the needs of the local load, the public power grid will supplement the power supply to the local load accordingly.

[0082] If the current value collected before the output current decreases is less than the current value collected after the output current decreases, it indicates that the grid-connected power generation system may be at a low power generation level or the local load may be at a high load level. In this case, the public grid will supply power to the local load. Therefore, as the output current decreases, the public grid needs to supply more power to the local load, resulting in a larger current value collected after the output current decreases.

[0083] It should be noted that in actual use, current changes may be nonlinear. Factors such as load fluctuations, changes in power generation, and fluctuations in public grid voltage may cause nonlinear changes in current in a short period of time. Therefore, the intelligent current transformer in this embodiment has high sensitivity and accuracy, and can cope with these nonlinear factors and accurately identify current changes.

[0084] In this embodiment, by controlling the output current of the grid-connected inverter and combining it with the current value collected by the intelligent current transformer, the grid-connected power generation status can be quickly determined without the need to collect voltage data, thus improving the efficiency and safety of the process. Furthermore, timely determination that the grid-connected power generation status corresponds to an electricity consumption status allows for timely adjustment of the grid-connected power generation system's output power, improving energy utilization.

[0085] Following the above embodiments, when the grid-connected power generation state is the power consumption state, it is necessary to adjust the output of the grid-connected inverter so that the grid-connected power generation system can enter the maximum power generation state as soon as possible. In an exemplary embodiment, as shown in Figure 4, the method further includes:

[0086] When the grid-connected power generation status is determined to be the power consumption status, the control current sampling device collects the current again to obtain the current value.

[0087] S500, increase the output current of the grid-connected power converter, return to S300, until the current value collected before the output current is increased is less than or equal to the current value collected after the output current is increased.

[0088] Following the above embodiments, when it is determined that the grid-connected power generation system is in a power consumption state, it means that the output current of the current grid-connected inverter is insufficient to meet the load demand of the local load. The local load also obtains additional power from the public grid. Therefore, in this embodiment, the grid-connected inverter is controlled to increase the output current, and the operating state of the grid-connected power generation system is adjusted by controlling the intelligent current transformer to collect the current value in a cyclic manner, so that the grid-connected power generation system can enter the maximum power output state as soon as possible.

[0089] Specifically, when the smart transformer reduces its output current for the first time after power-on, if the current value collected before the reduction is less than the current value collected after the reduction, this indicates that the output current has decreased while the current output from the public grid has increased. At this time, the grid-connected generation state is the power consumption state. Further, the main control module of the smart transformer sends a control command to the grid-connected inverter, instructing the inverter to increase its output current to increase the power supply from the grid-connected generation system to the local loads and decrease the power supply from the public grid to the local loads. Furthermore, the intelligent current transformer controls the sampling coil to collect the current value again, and compares the newly collected current value with the current value collected before the output current was increased. If the current value collected before the output current was increased is greater than the current value collected before the output current was increased, it indicates that the output current has increased and the current value output by the public grid has decreased. At this time, the grid-connected power generation system is still in a power consumption state, and it is necessary to continuously increase the output current of the grid-connected inverter until the output current of the grid-connected inverter can no longer be increased, and the grid-connected power generation system enters the maximum power generation state; or if it is determined that the current value collected before the output current was increased is less than the current value collected after the output current was increased, it indicates that the output current has increased too much, and the grid-connected power generation system enters the power feeding state again, and then enters the control loop for adjusting the power feeding state described in the other embodiments above, so that the grid-connected power generation system enters the zero power feeding state and reduces the reverse current phenomenon.

[0090] It should be noted that this embodiment uses two control cycles—one for adjusting the power supply state and the other for adjusting the power consumption state—to dynamically and continuously regulate the operating state of the grid-connected power generation system. This ensures that the system neither supplies power nor fails to reach its maximum power output. Furthermore, if the current value collected before adjusting the output current equals the current value collected after adjusting the output current in either of these two control cycles, it indicates that the adjustment range of the output current may be consistent with the change in the local load. This state is often unstable, and the grid-connected power generation system may re-enter a power supply state or a power consumption state over time. Therefore, these two control cycles operate in real-time and continuously. Even if the above phenomenon occurs, the adjustment of the output current and the cycle of the intelligent current transformer collecting current values ​​continue to ensure that the grid-connected power generation system provides stable power to the local load over a long period.

[0091] In this embodiment, when the grid-connected power generation system is in a power consumption state, increasing the output current can effectively reduce the energy waste caused by the current system imbalance and improve the energy utilization rate of the grid-connected power generation system.

[0092] Following the above embodiments, the magnitude and frequency of adjustment are crucial in adjusting the output current of the grid-connected inverter. In one exemplary embodiment, increasing the output current of the grid-connected power converter includes: determining an output current adjustment value based on the difference between the current value collected before the output current decreases or increases and the current value collected after the output current decreases or increases; and increasing the output current of the grid-connected power converter based on the output current adjustment value.

[0093] Following the above embodiments, regardless of whether the output current is increased or decreased, the subsequent adjustment range of the output current can be determined based on the difference in current values ​​collected by the smart transformer before and after increasing or decreasing the output current. This is because the current value difference can reflect, to a certain extent, the gap between the current operating state of the grid-connected power generation system and the zero-feed state or the maximum power generation state. In specific implementation, the actual output current adjustment range can be positively correlated with the current value difference, or calculated based on the current value difference using PID (Proportional, Integral, Differential) algorithms or other adaptive algorithms. Furthermore, a trained neural network model, such as a trained Long Short-Term Memory model trained using historically collected current data, can be deployed in the main control module of the smart transformer. This model can generate adjustment strategies based on the current value currently collected by the smart transformer and local load changes, including information such as the adjustment range and frequency of the output current, so that the grid-connected power generation system can quickly enter the zero-feed state or the maximum power generation state. Furthermore, the current difference can be directly used as the output current adjustment value, or when the grid-connected power generation system needs to reduce the output current, the output current adjustment value can be made slightly larger than the current difference. Although this may lead to over-adjustment, it can effectively enable the grid-connected power generation system to enter the zero-feed state as soon as possible, improving power safety. When the output current needs to be increased, the output current adjustment value can be made slightly smaller than the current difference to reduce the reverse current phenomenon caused by over-adjustment and improve power safety.

[0094] In this embodiment, the adjustment range of the subsequent output current is determined based on the difference in current values, enabling the grid-connected power generation system to better cope with changes in local load and the public power grid. Furthermore, by precisely controlling the adjustment range of the output current, the situation of over-supply or under-supply can be reduced, maximizing the optimization of the operating status of the grid-connected power generation system and improving the overall energy utilization efficiency of the grid-connected power generation system.

[0095] Following the above embodiments, the current value difference can reflect the operating status of the entire power system to a certain extent. In some embodiments, the present application further includes: comparing the current value difference with a preset current value difference threshold, and triggering a preset alarm mechanism if the current value difference is greater than the preset current value difference threshold.

[0096] Specifically, in the process of determining the grid-connected power generation status in the above embodiments, although it is assumed that the local load will not change in a short period of time, if the local load changes significantly in a short period of time, even if the output current is reduced slightly, the difference between the current values ​​collected by the smart transformer before and after the reduction of the output current may be large. This indicates that the current between the public power grid, the grid-connected power generation system and the local load may have fluctuated significantly.

[0097] Therefore, when the current values ​​collected by the smart transformer before and after the output current adjustment show significant abnormal fluctuations, such as a current value difference exceeding a preset current value difference threshold, the main control module of the smart transformer may have difficulty identifying whether the current fluctuation is due to a change in the power supply relationship between the public power grid, the grid-connected power generation system, and the local load, or a significant change in the local load. In this case, the main control module of the smart transformer can periodically collect the current value from the grid side without reducing the output current, for example, every 100ms. If the current value from the grid side still shows significant abnormal fluctuations without reducing the output current, it indicates that the local load may have undergone significant changes in a short period of time, posing a certain safety hazard. Therefore, the main control module of the smart transformer triggers a preset alarm mechanism, such as an audible and visual alarm (flashing lights and / or a buzzer alarm). It can also send alarm information to the user's or responsible personnel's mobile phone terminal via wireless communication to remind them of potential safety risks.

[0098] In practical applications, significant abnormal fluctuations in the current value on the grid side may also be caused by abnormal operation of the public power grid or grid-connected power generation system. In this case, the main control module in the smart transformer can also instruct relevant sensing devices to collect data via wireless communication, and analyze the hardware facilities in the power system, such as grid-connected inverters and sampling coils, based on the data collected by the sensing devices to determine whether there are any faults. If a fault is found, the main control module can also push alarm information to users or other responsible personnel, such as by sending alarm information to the mobile terminals of users or other responsible personnel, specifically by flashing lights, buzzer alarms, etc., to remind them of potential safety risks.

[0099] In this embodiment, the main control module of the intelligent transformer can not only adjust the output current to regulate the grid-connected power generation state, but also analyze the potential safety risks of the entire power system based on the current value difference and the preset current value difference threshold, and trigger the preset early warning mechanism, thereby timely discovering and responding to potential safety risks and improving the safety of the entire power consumption process.

[0100] To provide a clearer explanation of the grid-connected power generation status determination method provided in this application, the following description is provided in conjunction with a detailed embodiment and Figure 5:

[0101] S401: After the current sampling device is powered on, the current value collected by the current sampling device is obtained.

[0102] S402 reduces the output current of the grid-connected power converter.

[0103] S403 controls the current sampling device to collect the current again and obtain the current value.

[0104] S404 determines the adjustment method of the previous output current and compares the current value collected before the output current adjustment with the current value collected after the output current adjustment.

[0105] S405: If the current value collected before the output current decreases is greater than the current value collected after the output current decreases, the grid-connected power generation state is determined to be a power feeding state, and the process returns to S402 until the current value collected before the output current decreases is less than or equal to the current value collected after the output current decreases.

[0106] S406 If the current value collected before the output current decreases is less than the current value collected after the output current decreases, or if the current value collected before the output current increases is greater than the current value collected after the output current increases, the grid-connected power generation state is determined to be the power consumption state.

[0107] S407, increase the output current of the grid-connected power converter, return to S403, until the current value collected before the output current is increased is less than or equal to the current value collected after the output current is increased.

[0108] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages of other steps.

[0109] Based on the same inventive concept, this application also provides a grid-connected power generation status determination device for implementing the grid-connected power generation status determination method described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in one or more embodiments of the grid-connected power generation status determination device provided below can be found in the limitations of the grid-connected power generation status determination method described above, and will not be repeated here.

[0110] In an exemplary embodiment, as shown in FIG6, a grid-connected power generation status determination device 500 is provided, including: a first sampling module 510, a current adjustment module 520, a second sampling module 530, and a status judgment module 540, wherein:

[0111] The first sampling module 510 is used to acquire the current value collected by the current sampling device after the current sampling device is powered on.

[0112] The current adjustment module 520 is used to adjust the output current of the grid-connected power converter.

[0113] The second sampling module 530 is used to control the current sampling device to collect the current again and obtain the current value.

[0114] The status judgment module 540 is used to compare the current value collected before the output current adjustment with the current value collected after the output current adjustment to determine the grid-connected power generation status.

[0115] In an exemplary embodiment, the current adjustment module 520 is further configured to reduce the output current of the grid-connected power converter, and the state determination module 540 is further configured to determine that the grid-connected power generation state is a power supply state if the current value collected before the output current reduction is greater than the current value collected after the output current reduction. The grid-connected power generation state determination device 500 is further configured to, when the grid-connected power generation state is determined to be a power supply state, control the current adjustment module 520 to perform the operation of reducing the output current of the grid-connected power converter again, until the current value collected before the output current reduction is less than or equal to the current value collected after the output current reduction.

[0116] In an exemplary embodiment, the state determination module 540 is further configured to determine the grid-connected power generation state as an electricity consumption state if the current value collected before the output current decreases is less than the current value collected after the output current decreases.

[0117] In an exemplary embodiment, the grid-connected power generation status determination device 500 is further configured to, when determining that the grid-connected power generation status is an electricity consumption status, control the current adjustment module 520 to increase the output current of the grid-connected power converter, and execute the operation of controlling the current sampling device to collect the current again, until the current value collected before the output current increases is less than or equal to the current value collected after the output current increases.

[0118] In an exemplary embodiment, the current adjustment module 520 is further configured to determine an output current adjustment value based on the current value collected before the output current decreases or increases and the current value collected after the output current decreases or increases, and to increase the output current of the grid-connected power converter based on the output current adjustment value.

[0119] In an exemplary embodiment, the status judgment module 540 is further configured to compare the current value difference with a preset current value difference threshold, and trigger a preset alarm mechanism if the current value difference is greater than the preset current value difference threshold.

[0120] Each module in the aforementioned grid-connected power generation status determination device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device, or stored in the memory of a computer device as software, so that the processor can call and execute the corresponding operations of each module.

[0121] In an exemplary embodiment, a computer device is provided, which may be a server, and its internal structure diagram is shown in Figure 7. The computer device includes a processor, memory, input / output interfaces (I / O), and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is connected to the system bus via the I / O interfaces. The processor of the computer device provides computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, computer programs, and a database. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The database of the computer device stores data from a current acquisition device. The I / O interfaces of the computer device are used for exchanging information between the processor and external devices. The communication interface of the computer device is used for communication with external terminals via a network connection. When the computer program is executed by the processor, it implements a method for determining the state of grid-connected power generation.

[0122] Those skilled in the art will understand that the structure shown in Figure 7 is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0123] In one exemplary embodiment, a computer device is provided, including a memory and a processor. The memory stores a computer program, and the processor executes the computer program to implement the steps in the embodiments of the grid-connected power generation state determination methods described above.

[0124] In some embodiments, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps in any of the above embodiments of the grid-connected power generation status determination method.

[0125] In some embodiments, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in any of the above embodiments of the grid-connected power generation status determination method.

[0126] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0127] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0128] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0129] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for determining grid-connected power generation status, characterized in that, An application to a grid-connected power generation system, wherein the grid-connected power generation system includes an interconnected current sampling device and a grid-connected power converter, the current sampling device being connected to the output terminal of the grid side, and the current being measured based on the principle of electromagnetic induction, the method comprising: After the current sampling device is powered on, the current value collected by the current sampling device is acquired; Adjust the output current of the grid-connected power converter; The current sampling device is controlled to collect the current again to obtain the current value; The grid-connected power generation status is determined by comparing the current value collected before the output current adjustment with the current value collected after the output current adjustment.

2. The method according to claim 1, characterized in that, Adjusting the output current of the grid-connected power converter includes: Reduce the output current of the grid-connected power converter; The step of comparing the current value collected before the output current adjustment with the current value collected after the output current adjustment to determine the grid-connected power generation status includes: If the current value collected before the output current decreases is greater than the current value collected after the output current decreases, the grid-connected power generation state is determined to be a power feeding state, and the process returns to the step of reducing the output current of the grid-connected power converter until the current value collected before the output current decreases is less than or equal to the current value collected after the output current decreases.

3. The method according to claim 2, characterized in that, The step of comparing the current value collected before the output current adjustment with the current value collected after the output current adjustment to determine the grid-connected power generation status includes: If the current value collected before the output current decreases is less than the current value collected after the output current decreases, the grid-connected power generation state is determined to be a power consumption state.

4. The method according to claim 3, characterized in that, After determining that the grid-connected power generation state is an electricity consumption state, the method further includes: Increase the output current of the grid-connected power converter; Return to the step of controlling the current sampling device to collect the current again, until the current value collected before the output current increases is less than or equal to the current value collected after the output current increases.

5. The method according to claim 4, characterized in that, Increasing the output current of the grid-connected power converter includes: The output current adjustment value is determined based on the difference between the current value collected before the output current decreases or increases and the current value collected after the output current decreases or increases. The output current of the grid-connected power converter is increased according to the output current adjustment value.

6. The method according to claim 5, characterized in that, The method further includes: Compare the current value difference with a preset current value difference threshold; If the difference in current values ​​exceeds the preset threshold for the difference in current values, a preset alarm mechanism is triggered.

7. The method according to any one of claims 1 to 6, characterized in that, The current sampling device is inserted into the live or neutral wire at the entrance of the household.

8. The method according to any one of claims 1 to 6, characterized in that, The current sampling device includes a main control module, a sampling coil, and a power supply coil. The sampling coil measures the current based on the principle of electromagnetic induction.

9. The method according to any one of claims 1 to 6, characterized in that, The power supply circuit of the current sampling device includes a capacitor or a rechargeable battery.

10. The method according to any one of claims 1 to 6, characterized in that, The current sampling device is an intelligent current transformer.

11. The method according to any one of claims 1 to 6, characterized in that, The grid-connected power converter is a grid-connected inverter.

12. A device for determining the grid-connected power generation status, characterized in that, Deployed in a grid-connected power generation system, the grid-connected power generation system includes an interconnected current sampling device and a grid-connected power converter. The current sampling device is connected to the output terminal of the grid side and measures the current based on the principle of electromagnetic induction. The device includes: The first sampling module is used to acquire the current value collected by the current sampling device after the current sampling device is powered on. A current adjustment module is used to adjust the output current of the grid-connected power converter; The second sampling module is used to control the current sampling device to collect the current again and obtain the current value; The status judgment module is used to compare the current value collected before the output current adjustment with the current value collected after the output current adjustment to determine the grid-connected power generation status.

13. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 11.

14. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 11.

15. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 11.

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