Reverse power automatic control method and device and new energy power generation system

Abstract

The application relates to an anti-reverse power automatic control method and device and a new energy power generation system, wherein the anti-reverse power automatic control method collects real-time power of a property right decomposition point, compares the real-time power with preset power, judges whether reverse power appears or not, controls a collection line switch to be turned off when the reverse power appears, so as to reduce the output of the new energy power generation system and prevent the reverse power from being generated. Compared with the direct turn-off of a grid-connected switch when the reverse power appears in the traditional technology, the application can reduce the waste of energy and improve the consumption level of users.

Description

Technical Field

[0001] This invention relates to the field of new energy power generation control, and in particular to an automatic anti-reverse power control method, device, and new energy power generation system. Background Technology

[0002] With the development of new energy technologies, the State Grid Corporation of China currently adopts an encouraging and cooperative approach to distributed photovoltaic (PV) power generation. PV power generation includes three modes: self-consumption, self-consumption with surplus power fed into the grid, and full grid connection of generated electricity. Currently, the self-consumption mode is developing relatively slowly due to limitations in technology and the ability of owners to absorb the excess power.

[0003] Self-consumption projects typically employ a reverse power control cabinet. By comparing the power at the property boundary point with the control power setpoint, the output power of the inverter is adjusted or the photovoltaic power generation system is disconnected. The reverse power control cabinet communicates with the inverter via RS485, making the entire system highly dependent on this communication. If communication is interrupted, the reverse power control cabinet will directly disconnect the photovoltaic power generation system, resulting in a waste of photovoltaic power generation resources. Summary of the Invention

[0004] Therefore, it is necessary to provide an automatic reverse power control method, device, and new energy power generation system to address the problem of photovoltaic power generation resource waste caused by the direct disconnection of the photovoltaic power generation system by the reverse power control cabinet in the self-consumption mode of traditional technology.

[0005] An automatic power control method for preventing reverse power generation is used to control a renewable energy power generation system to prevent the power generated by the renewable energy power generation system from being fed back to the power grid. The renewable energy power generation system includes power generation units, a grid-connected switch, at least one busbar and a busbar switch corresponding to the busbar. One end of the busbar is connected to each power generation unit, and the other end of each busbar is connected to the busbar of the renewable energy power generation system through the busbar switch. The busbar of the renewable energy power generation system is connected to the load busbar through the grid-connected switch. The method includes:

[0006] Detect the real-time power at the property boundary point;

[0007] Compare the real-time power with the preset power;

[0008] When the real-time power is greater than the preset power, at least one busbar switch is closed to enable the new energy power generation system to supply power to the load.

[0009] When the real-time power is less than the preset power, at least one of the busbar switches is controlled to disconnect, so as to prevent the new energy power generation system from supplying power to the grid.

[0010] When the real-time power equals the preset power, the current state is maintained.

[0011] The automatic control method for preventing reverse power provided in the above embodiments collects the real-time power of the property allocation point, compares the real-time power with the preset power, and determines whether reverse power has occurred. When reverse power occurs, the control of the collection line switch is disconnected to reduce the output of the new energy power generation system and prevent the generation of reverse power. Compared with the traditional technology of directly disconnecting the grid connection switch when reverse power occurs, this application can reduce energy waste and improve the user's absorption level.

[0012] In one embodiment, controlling at least one busbar switch to close when the real-time power is greater than the preset power includes:

[0013] When the real-time power is greater than the preset power, the real-time power is positive power, and the status of the collection line switch in the new energy power generation system is detected.

[0014] When at least one of the busbar switches is in the off state, the busbar corresponding to the busbar switch in the off state is determined, and the rated power of the off busbar is compared with the magnitude of a first difference, wherein the first difference is the difference between the real-time power and the preset power.

[0015] If the first difference is greater than the rated power of the disconnected busbar, then the switch of the busbar corresponding to the disconnected busbar is controlled to close.

[0016] In one embodiment, controlling at least one of the busbar switches to disconnect when the real-time power is less than the preset power includes:

[0017] When the real-time power is less than the preset power, the real-time power is the reverse power, and the state of the bus switch is detected to find the bus switch that is in the closed state.

[0018] Identify the busbar corresponding to the busbar switch that is in the closed state, and locate the target busbar with the minimum rated power;

[0019] Compare the second difference with the target power, wherein the second difference is the difference between the rated power of the target busbar and the real-time power, and the target power is the sum of the rated power of the conducting busbars and the set power;

[0020] When the second difference is less than the target power, the switch of the busbar corresponding to the target busbar is turned off.

[0021] In one embodiment, when the second difference is greater than or equal to the target power, the grid connection switch of the new energy power generation system is disconnected.

[0022] An automatic power control device for preventing reverse power generation is used in a new energy power generation system and is installed at the property boundary point. The automatic power control device for preventing reverse power generation includes:

[0023] An AC board is used to collect the real-time voltage and real-time current at the property boundary point.

[0024] The CPU board, connected to the AC board, is used to calculate the real-time power based on the real-time voltage and the real-time current. The CPU board has a preset power stored in its memory. The CPU board is also used to compare the real-time power with the preset power.

[0025] An output board, connected to the CPU board, includes multiple sets of closing outputs and multiple sets of tripping outputs. The closing outputs are connected to the busbar switch and used to control the busbar switch to close. The tripping outputs are correspondingly connected to the busbar switch and the grid-connected switch and used to control the busbar switch and the grid-connected switch to open. When the real-time power is greater than the preset power, the CPU board controls at least one busbar switch to close by controlling the closing output, so that the new energy power generation system supplies power to the load. When the real-time power is less than the preset power, the CPU board controls at least one busbar switch to open by controlling the tripping output, so as to prevent the new energy power generation system from supplying power to the grid.

[0026] The automatic power control device for preventing reverse power provided in the above embodiment can obtain the real-time power of the property boundary point by setting the AC board 110 to collect the real-time voltage and real-time current of the property boundary point. The CPU board 120 compares the real-time power of the property boundary point with the preset power and the collected status of the busbar switch to comprehensively determine whether to engage or disengage the busbar. When the busbar needs to be engaged, the closing output is controlled to close the busbar switch to engage the busbar. When the busbar needs to be disengaged, the trip output is controlled to open the busbar switch to disconnect the output of the busbar. This adjusts the output power of the new energy power generation system so that the output power of the new energy power generation system is balanced with the consumption level of the local load, preventing reverse power generation.

[0027] In one embodiment, an input board is further included, which is connected to the CPU board. When the real-time power is greater than a preset power, the input board detects the state of the bus switch and sends the state of the bus switch to the CPU board. When at least one bus switch is in the open state, the CPU board compares the rated power of the disconnected bus with the first difference. If the first difference is greater than the rated power of the disconnected bus, the CPU board controls the closing output to control the bus switch to close. The first difference is the difference between the real-time power and the preset power.

[0028] In one embodiment, the input board is further configured to collect the state of the busbar switch when the real-time power is less than the preset power in order to find the busbar switch in the closed state, and send it to the CPU board. The CPU board compares the rated power of each closed busbar and finds the target busbar with the minimum rated power.

[0029] The CPU board determines the magnitude of a second difference between the rated power of the target busbar and the real-time power and the sum of the rated power of each busbar in the closed state. When the second difference is less than the target power, the CPU board controls the busbar switch corresponding to the target busbar to open by controlling the trip output. The target power is the sum of the rated power of the busbars in the conducting state and the set power.

[0030] In one embodiment, when the second difference is greater than or equal to the sum of the rated power, the CPU board controls the grid connection switch of the new energy power generation system to disconnect by controlling the corresponding trip output.

[0031] In one embodiment, the input board is also connected to an external power source to provide operating power to the AC board, the output board, and the CPU board.

[0032] A new energy power generation system includes the aforementioned anti-reverse power automatic control device. Attached Figure Description

[0033] Figure 1 A flowchart of an automatic power control method for preventing reverse power is provided as an embodiment of this application;

[0034] Figure 2 A flowchart of an automatic power control method for preventing reverse power is provided in another embodiment of this application;

[0035] Figure 3 A flowchart of an automatic power control method for preventing reverse power is provided in another embodiment of this application;

[0036] Figure 4 A schematic diagram of an anti-reverse power automatic control device module provided in one embodiment of this application;

[0037] Figure 5 A schematic diagram of a new energy power generation system provided for one embodiment of this application. Detailed Implementation

[0038] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0039] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0041] Please see Figure 1 One embodiment of this application provides an automatic anti-reverse power control method, comprising the following steps:

[0042] S100: Detects the real-time power at the property boundary point.

[0043] This embodiment provides an automatic power control method for preventing reverse power generation in a new energy power generation system, which can be a photovoltaic power generation system, a wind power generation system, etc. In the self-consumption mode of the new energy power generation system, the energy flow direction is as follows: the energy of the new energy power generation system is provided to the local load. When the local load requires more energy than the new energy power generation system can provide, the grid energy is used as a supplement.

[0044] In the self-consumption mode, the electricity generated by the new energy power generation system is only used to supply local loads. Therefore, it is necessary to prevent the new energy power generation system from generating too much energy and the excess energy from flowing into the grid. The energy flowing into the grid is reverse power. When reverse power occurs, the energy of the new energy power generation system needs to be adjusted to achieve zero power output to the grid.

[0045] This embodiment adjusts the output energy of the new energy power generation system by regulating the number of connecting lines, achieving zero power output to the grid. The new energy power generation system includes at least one power generation unit, at least one connecting line, and corresponding connecting line switches and grid-connected switches. Each connecting line has one end connected to a power generation unit, and the other end connected to one end of the connecting line switch. The other end of each connecting line switch is connected to the new energy power generation system bus, which is connected to the local load bus via a grid-connected line. The grid-connected line has a grid-connected switch. First, the grid-connected switch is checked for closure. When closed, the anti-reverse power automatic control device collects the real-time power at the property boundary point and determines whether the real-time power is reverse power. The property boundary point is the first circuit breaker boundary point between the power grid and the user's distribution room. When power flows out of the grid, it is considered positive power; when power flows into the grid, it is considered reverse power. In this embodiment, real-time power flowing out of the grid is defined as positive, and real-time power flowing into the grid is defined as negative. Specifically, it can detect the voltage and current at the property boundary point, and then calculate the real-time power at the property boundary point.

[0046] S200: Compares the real-time power with the preset power.

[0047] The automatic power control device for preventing reverse power has a preset power. When the real-time power is collected, it is compared with the preset power to determine whether reverse power has been generated.

[0048] S300: When the real-time power is greater than the preset power, at least one busbar switch is closed to enable the new energy power generation system to supply power to the load.

[0049] When the real-time power is greater than the preset power, the real-time power is positive power, which means that the grid is supplying power to the local load. This indicates that the local load is consuming more electricity from the grid at this time. Therefore, it is necessary to connect the collection line and use a new energy power generation system to supply power to the local load in order to reduce the grid's electricity consumption.

[0050] Specifically, the new energy power generation system includes multiple power generation units. Each power generation unit feeds power to the new energy power generation system bus through a collection line. The generated power is finally connected to the user's local load through the grid connection line. Both the collection line and the grid connection line are controlled by switches. The power generation of the new energy power generation system can be controlled by opening and closing the switches.

[0051] The anti-reverse power automatic control device is connected to the collector switch to control the closing and closing of the collector switch. When the collector needs to be connected, the anti-reverse power automatic control device controls at least one collector switch to close so that the new energy power generation system can supply power to the load.

[0052] S400: When the real-time power is less than the preset power, at least one busbar switch is controlled to disconnect to prevent the new energy power generation system from supplying power to the grid.

[0053] When the real-time power is less than the preset power, the real-time power is considered reverse power. This means that the renewable energy generation system not only supplies power to the local load but also feeds additional electricity back to the grid. Therefore, it is necessary to reduce the number of busbars to decrease the power generation of the renewable energy generation system. The anti-reverse power automatic control device reduces the output power of the renewable energy system by controlling at least one busbar switch to disconnect, thereby preventing the energy of the renewable energy generation system from being fed back to the grid.

[0054] S500: When the real-time power equals the preset power, the current state is maintained.

[0055] When the real-time power equals the preset power, it indicates that there is currently no reverse power input to the grid, and the local load absorption level is in balance with the power generation of the new energy power generation system. In this case, the current state is maintained, and neither the collection line is connected nor disconnected from the collection line.

[0056] The automatic control method for preventing reverse power provided in the above embodiments collects the real-time power of the property allocation point, compares the real-time power with the preset power, and determines whether reverse power has occurred. When reverse power occurs, the control of the collection line switch is disconnected to reduce the output of the new energy power generation system and prevent the generation of reverse power. Compared with the traditional technology of directly disconnecting the grid connection switch when reverse power occurs, this application can reduce energy waste and improve the user's absorption level.

[0057] Please see Figure 2 In one embodiment, controlling at least one busbar switch to close when the real-time power is greater than a preset power includes:

[0058] S310: When the real-time power is greater than the preset power, the real-time power is positive power, and the switching status of the collection line in the new energy power generation system is detected.

[0059] Specifically, when the real-time power exceeds the preset power, it indicates that the local load is consuming a large amount of electricity from the grid, thus requiring the aggregation line to be activated. Before activating the aggregation line, the anti-reverse power automatic control device first collects the status of the aggregation line switches to determine whether control of the aggregation line switches is necessary. When all aggregation line switches are closed, meaning all aggregation lines are in use and the output of the new energy power generation system reaches its maximum, then there is no need to control the aggregation line switches to close.

[0060] S320: When at least one busbar switch is in the open state, determine the busbar corresponding to the open busbar switch, and compare the rated power of the open busbar with the magnitude of a first difference.

[0061] When at least one busbar switch is in the open state, there are still unconnected busbars. The reverse power prevention automatic control device needs to determine whether to connect a particular busbar. If connecting the busbar will not result in reverse power, then the corresponding busbar can be connected. The reverse power prevention automatic control device obtains a first difference value by subtracting the real-time power from the preset power, and compares the first difference value with the rated power to determine whether the corresponding busbar needs to be connected.

[0062] S330: If the first difference is greater than the rated power of a disconnected busbar, then control the corresponding busbar switch to close.

[0063] When the first difference is greater than the rated power of a busbar that is currently disconnected, connecting that busbar will reduce the power consumption of the grid and will not generate reverse power. When the first difference is less than the rated power of a busbar that is currently disconnected, connecting the busbar will result in some power being fed back to the grid, generating reverse power; in this case, the busbar should not be connected. It should be noted that neither the real-time power nor the first difference is fixed; both the real-time power and the preset power will change each time a busbar is connected.

[0064] Specifically, when the Pth i and P i+1 If the bus switch is in the open state, then first compare the Pth switch. i The magnitude of the difference between the rated power of the charging line and the first value, if the first difference is greater than the Pth value... i The rated power of the busbar, the reverse power automatic control device controls the P-th line. i The switch corresponding to the Pth busbar is closed to input the Pth busbar. i A convergence line. At this time, the anti-reverse power automatic control device detects the real-time power at the property decomposition point again, and calculates the difference between the real-time power and the preset power to obtain the first difference value. Compare the first difference value at this time, and then the Pth... i+1 The rated power of the busbar, if the first difference is less than the Pth... i+1 If the rated power of the busbar is P, then the Pth busbar will not be connected. i+1 A junction line is used to prevent reverse power generation.

[0065] Please see Figure 3 When the real-time power is less than the preset power, controlling at least one busbar switch to disconnect includes the following steps:

[0066] S410: When the real-time power is less than the preset power, the real-time power is the reverse power. The status of the bus switch is detected to find the bus switch that is in the closed state.

[0067] Specifically, when the real-time power is less than the preset power, it indicates that the local load's electricity consumption is low. In addition to supplying the local load, some of the electricity generated by the renewable energy power generation system flows into the grid, resulting in reverse power. At this time, it is necessary to disconnect some of the collection lines to reduce the output of the renewable energy power generation system and eliminate the reverse power.

[0068] Before disconnecting the collector switch, the status of the collector switch needs to be detected to determine the position of the collector switch that is closed. Based on the obtained status of the collector switch, at least one collector switch should be disconnected to ensure that the power generation of the new energy power generation system is in balance with the consumption of the local load.

[0069] S420: Determine the busbar corresponding to the busbar switch that is in the closed state, and find the target busbar with the minimum rated power.

[0070] To improve the user's absorption capacity, the target bus line with the minimum rated power is usually disconnected first. If reverse power still exists after disconnecting the target bus line, the target bus line with the next minimum rated power is then disconnected.

[0071] The reverse power detection device has the rated power of each busbar pre-stored. When a busbar switch in a closed state is detected, the position of the conducting busbar can be determined, the rated power of each conducting busbar can be compared, and the target busbar with the minimum rated power can be found.

[0072] S430: The second difference is obtained by subtracting the rated power of the minimum busbar from the real-time power. The second difference is compared with the target power, wherein the target power is the sum of the rated power of the busbars in the conducting state and the sum of the set power.

[0073] When the real-time power is less than the preset power, the real-time power is considered reverse power. Therefore, the second difference, obtained by subtracting the rated power of the minimum busbar from the real-time power, is the sum of the absolute values ​​of the minimum rated power and the real-time power. This second difference is compared with the target power, which is the sum of the rated power of the busbars in the conducting state and the set power. The set power is a preset power value, which can be positive, negative, or zero. In this embodiment, the set power is zero. When the set power is zero, the target power is the sum of the rated power of the busbars in the conducting state. By comparing the two values, it is determined whether cutting off the busbar can eliminate the reverse power.

[0074] S440: When the second difference is less than the target power, the switch of the corresponding busbar for the target busbar is opened.

[0075] When the sum of the absolute values ​​of the minimum rated power and the real-time power is less than the sum of the rated power of the connected busbars, it indicates that there will be no reverse power when at least one busbar is connected. In this case, reducing the number of connected busbars can prevent reverse power from occurring. Therefore, reverse power can be controlled by gradually disengaging the busbars. After disconnecting the target busbar, the real-time power and the preset power are checked again. If the real-time power is greater than the preset power, the busbar is not disconnected again. If the real-time power is still less than the preset power, the target busbar with the minimum rated power among the remaining connected busbars is disconnected.

[0076] When the sum of the absolute values ​​of the minimum rated power and the real-time power is greater than the sum of the rated power of the connected busbars, it indicates that there will still be reverse power even if only one busbar is connected. At this time, cutting off the busbars can no longer reduce the reverse power. Therefore, the grid connection switch is directly cut off to cut off the output of the new energy power generation system and the power grid is used to supply power to the local load.

[0077] The automatic reverse power control method provided in the above embodiments controls the connection of the collection line when the real-time power is greater than the preset power, thereby increasing the consumption of the new energy power generation system by the local load and thus improving the absorption level. When the real-time power is less than the preset power, the collection line is disconnected to balance the power generation of the new energy power generation system with the consumption level of the local load and eliminate reverse power.

[0078] Please see Figure 4 One embodiment of this application provides an automatic reverse power control device, which can be used in self-consumption projects with a single unit capacity of 6MWp to 20MWp connected to the 10kV or 35kV grid. Of course, it is not limited to projects with a capacity of 6MWp to 20MWp. The automatic reverse power control device includes an AC board 110, a CPU (Central Processing Unit) board 120, and an output board 130.

[0079] The reverse power automatic control device is installed at the grid connection point. The AC board 110 may include a voltage detector and a current detector. The voltage detector is used to collect the real-time voltage at the property boundary point, and the current detector is used to detect the real-time current at the property boundary point. The collected real-time voltage and real-time current are then sent to the CPU board 120.

[0080] CPU board 120 calculates the real-time power at the property boundary point based on real-time voltage and real-time current. CPU board 120 includes a storage unit and a logic operation unit. The storage unit stores a preset power. CPU board 120 can compare the calculated real-time power with the preset power. The logic operation unit is responsible for the logical comparison and issues opening and closing commands.

[0081] The output board 130 is connected to the CPU board 120. The output board 130 includes n combination gate outputs and n+1 trip outputs. The n combination gate outputs are connected to n collection line switches, the n trip outputs are connected to n collection line switches, and one trip output is connected to the grid-connected switch.

[0082] When the real-time power is greater than the preset power, the real-time power is positive power, meaning the grid is supplying power to the local load. This indicates that the local load is consuming a large amount of electricity from the grid. Therefore, it is necessary to connect a collection line and use a new energy power generation system to supply power to the local load, thereby reducing the grid's electricity consumption. At this time, the CPU board 120 controls at least one collection line switch to close via the control closing output, allowing the new energy power generation system to supply power to the load. When the real-time power is less than the preset power, the real-time power is reverse power, meaning the new energy power generation system is not only supplying power to the local load but also feeding additional electricity back to the grid. Therefore, it is necessary to reduce the number of collection lines connected to lower the input power at the grid connection point, thereby controlling the real-time power at the property boundary point. At this time, the CPU board 120 controls at least one collection line switch to open via the control trip output, reducing the output power of the new energy system, balancing the power generation of the new energy power generation system with the consumption of the local load, and preventing the energy of the new energy power generation system from being fed back to the grid.

[0083] The automatic power control device for preventing reverse power provided in the above embodiment can obtain the real-time power of the property boundary point by setting the AC board 110 to collect the real-time voltage and real-time current of the property boundary point. The CPU board 120 compares the real-time power of the property boundary point with the preset power and the collected status of the busbar switch to comprehensively determine whether to engage or disengage the busbar. When the busbar needs to be engaged, the closing output is controlled to close the busbar switch to engage the busbar. When the busbar needs to be disengaged, the trip output is controlled to open the busbar switch to disconnect the output of the busbar. This adjusts the output power of the new energy power generation system so that the output power of the new energy power generation system is balanced with the consumption level of the local load, preventing reverse power generation.

[0084] In one embodiment, the anti-reverse power automatic control device further includes an input board 140, which is connected to the CPU board 120. The input board 140 is used to collect the switching status of the busbar when the real-time power exceeds a preset power, and then sends the switching status of the busbar to the CPU board 120. When the input board 140 detects that at least one busbar switch is in an open state, the CPU board 120 calculates a first difference between the rated power and the real-time power, and compares the rated power of the open busbar with the first difference. If the first difference is greater than the rated power of the open busbar, the CPU board controls the corresponding busbar switch to close via a control closing output.

[0085] For example, a new energy power generation system includes 5 collection lines, each of which is connected to a corresponding collection line switch. An input board 140 is connected to each collection line switch to collect its status. When the input board 140 collects the status of the Pth collection line switch... i The busbar switch connected to the busbar is in the off state, and the input board 140 will connect the Pth busbar. i The status of the switch of the connecting line is sent to the CPU board 120, then the CPU board 120 compares the Pth line switch status. i The magnitude of the difference between the rated power of the charging line and the first value, if the first difference is greater than the Pth value... i The rated power of the busbar is controlled by the CPU board 120 through the control closing output of the P line. i The switch corresponding to the Pth busbar is closed to input the Pth busbar. i A converging line.

[0086] When the real-time power is less than the preset power, the input board 140 collects the status of the busbar switches to locate the busbar switches in the closed state and sends the data to the CPU board 120. The CPU board 120 compares the rated power of each busbar in the closed state and locates the target busbar with the minimum rated power. The CPU board 120 calculates a second difference by subtracting the rated power of the target busbar from the real-time power. Since the real-time power at this time is the reverse power, the second difference is the sum of the minimum rated power and the absolute value of the real-time power. The second difference is compared with the target power, where the target power is the sum of the rated power of the busbars in the conducting state and the set power. The set power is a preset power value, which can be positive, negative, or zero. In this embodiment, the set power is zero. When the set power is zero, the target power is the sum of the rated power of the busbars in the conducting state. By comparing the two values, it is determined whether cutting off the busbar can eliminate the reverse power.

[0087] When the sum of the absolute values ​​of the minimum rated power and the real-time power is less than the sum of the rated power of the connected busbars, it indicates that there will be no reverse power when at least one busbar is connected. In this case, reducing the number of connected busbars can prevent reverse power from occurring. Therefore, reverse power can be controlled by gradually disengaging the busbars. The CPU board 120 controls the busbar switch of the target busbar to disconnect by controlling the trip output, thereby cutting off the target busbar and reducing reverse power. After disconnecting the target busbar, the CPU board 120 again judges the magnitude of the real-time power and the preset power. If the real-time power is greater than the preset power, the busbar will not be disconnected again. If the real-time power is still less than the preset power, the target busbar with the minimum rated power among the remaining connected busbars will continue to be disconnected.

[0088] When the sum of the absolute values ​​of the minimum rated power and the real-time power is greater than the sum of the rated power of the connected busbars, it indicates that there will still be reverse power even if only one busbar is connected. At this time, cutting off the busbars can no longer reduce the reverse power. Therefore, the CPU board directly cuts off the grid connection switch by controlling the trip output, cuts off the output of the new energy power generation system, and uses the power grid to supply power to the local load.

[0089] In one embodiment, the input board 140 is also connected to an external power source to provide power to the AC board 110, the output board 130, and the CPU board 120.

[0090] The automatic reverse power control device provided in the above embodiment, when the real-time power is greater than the preset power, the CPU board 120 controls the connection of the busbar to increase the consumption of the new energy power generation system by the local load, thereby improving the absorption level. When the real-time power is less than the preset power, the CPU board 120 controls the disconnection of the busbar to balance the power generation of the new energy power generation system with the consumption level of the local load, thus eliminating reverse power.

[0091] Please see Figure 5 One embodiment of this application provides a new energy power generation system, including the aforementioned anti-reverse power automatic control device 100. The new energy power generation system also includes multiple new energy power generation units 200, a collection line 300, and a grid-connected output line 400. The new energy power generation unit 200 can be a photovoltaic power generation unit, a wind power generation unit, etc.; this embodiment uses a photovoltaic power generation unit as an example. The photovoltaic power generation unit can be a solar panel, which is connected to the collection line 300. A collection line switch 310 is installed on each collection line 300, and the collection line 300 is connected to the busbar through the collection line switch 310. Multiple collection lines 300 are connected in parallel. The busbar of the new energy power generation system is connected to the grid-connected output line 400, which is connected to the busbar where the user load is located through the grid-connected switch 410 for local load use.

[0092] The reverse power automatic control device 100 includes an AC board 110, a CPU board 120, an output board 130, and an input board 140. The reverse power automatic control device 100 is installed at the grid connection point. The AC board 110 is used to collect real-time voltage and current at the property boundary point. The CPU board 120 is connected to the AC board 110 and is used to receive real-time voltage and current and calculate real-time power. The output board 130 is connected to the CPU board 120 and includes n combined circuit breaker outputs and n+1 trip outputs. The n combined circuit breaker outputs are connected to n busbar switches 310, the n trip outputs are connected to n busbar switches 310, and one trip output is connected to a grid connection switch 410. The input board 140 is also connected to the collection line switch 310 and the grid connection switch 410, and is used to collect the status of the collection line switch 310 and the grid connection switch 410 and send it to the CPU board 120, so that the CPU board 120 can control the corresponding collection line to be put into the new energy power generation system or to be taken out of the new energy power generation system according to the status of the collection line switch 310 and the grid connection switch 410 and the real-time power of the property rights decomposition point.

[0093] The new energy power generation system provided in the above embodiments has an automatic anti-reverse power control device equipped with multiple trip outputs and closing outputs. By detecting real-time power, the trip outputs and closing outputs are controlled to control the closing and opening of the bus switch, thereby connecting or disconnecting the bus, achieving the purpose of adjusting the power at the property boundary point, preventing reverse power, and improving the user's absorption level of the new energy power generation system.

[0094] 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.

[0095] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for automatic control of reverse power, characterized in that, A method for controlling a new energy power generation system to prevent the power generated by the new energy power generation system from being fed back to the power grid, the new energy power generation system including a power generation unit, a grid-connected switch, at least one busbar and a busbar switch corresponding to the busbar, one end of the busbar being connected to each of the power generation units, and the other end of each busbar being connected to the busbar of the new energy power generation system, the busbar of the new energy power generation system being connected to the load busbar through the grid-connected switch, the method comprising: Detect the real-time power at the property boundary point, which is the first circuit breaker boundary point between the power grid and the user's distribution room; Compare the real-time power with the preset power; When the real-time power is greater than the preset power, the real-time power is positive power, and the status of the collection line switch in the new energy power generation system is detected. When at least one of the busbar switches is in the off state, the busbar corresponding to the busbar switch in the off state is determined, and the rated power of the off busbar is compared with the magnitude of a first difference, wherein the first difference is the difference between the real-time power and the preset power. If the first difference is greater than the rated power of the disconnected busbar, then controlling the switch of the busbar corresponding to the disconnected busbar to close, so that the new energy power generation system supplies power to the load, includes: When the switches of the Pi-th and Pi+1-th bus lines are in the open state, the rated power of the Pi-th bus line is compared with the first difference. If the first difference is greater than the rated power of the Pi-th bus line, the switch of the corresponding bus line of the Pi-th bus line is closed to activate the Pi-th bus line. The real-time power at the property decomposition point is detected again, and the real-time power is compared with the preset power to obtain a new first difference. The rated power of the Pi+1-th bus line is determined by comparing the new first difference. If the new first difference is less than the rated power of the Pi+1-th bus line, the Pi+1-th bus line is not activated. When the real-time power is less than the preset power, the real-time power is the reverse power, and the state of the bus switch is detected to find the bus switch that is in the closed state. Identify the busbar corresponding to the busbar switch that is in the closed state, and locate the target busbar with the minimum rated power; Compare the second difference with the target power, wherein the second difference is the difference between the rated power of the target busbar and the real-time power, and the target power is the sum of the rated power of the conducting busbars and the set power; When the second difference is less than the target power, the switch of the busbar corresponding to the target busbar is opened to prevent the new energy power generation system from supplying power to the grid. When the second difference is greater than or equal to the target power, the grid connection switch of the new energy power generation system is disconnected. When the real-time power equals the preset power, the current state is maintained.

2. An automatic reverse power control device for use in a new energy power generation system, and installed at a property boundary point, wherein the property boundary point is the first circuit breaker boundary point between the power grid and the user's distribution room, characterized in that, The anti-reverse power automatic control device includes: An AC board is used to collect the real-time voltage and real-time current at the property boundary point. The CPU board, connected to the AC board, is used to calculate the real-time power based on the real-time voltage and the real-time current. The CPU board has a preset power stored in its memory. The CPU board is also used to compare the real-time power with the preset power. An output board, connected to the CPU board, includes multiple sets of closing outputs and multiple sets of tripping outputs. The closing outputs are connected to a busbar switch to control its closure. The tripping outputs are correspondingly connected to the busbar switch and a grid-connected switch to control their disconnection. When the real-time power exceeds the preset power, the CPU board controls at least one busbar switch to close via the closing outputs, enabling the renewable energy generation system to supply power to the load. When the real-time power is less than the preset power, the CPU board controls at least one busbar switch to open via the tripping outputs, preventing the renewable energy generation system from supplying power to the grid. An input board, connected to the CPU board, is used to detect the status of the busbar switch and send the status of the busbar switch to the CPU board when the real-time power is greater than the preset power. When at least one busbar switch is in the open state, the CPU board compares the rated power of the disconnected busbar with the magnitude of a first difference. If the first difference is greater than the rated power of the disconnected busbar, the CPU board controls the closing output to control the busbar switch to close. The first difference is the difference between the real-time power and the preset power. The input board is also used to collect the status of the busbar switch when the real-time power is less than the preset power in order to find the busbar switch that is in the closed state, and send it to the CPU board. The CPU board compares the rated power of each closed busbar and finds the target busbar with the minimum rated power. The CPU board determines the magnitude of the second difference between the rated power of the target busbar and the real-time power and the sum of the rated power of each busbar in the closed state. When the second difference is less than the target power, the CPU board controls the busbar switch corresponding to the target busbar to open by controlling the trip output. The target power is the sum of the rated power of the busbars in the conducting state and the set power. When the second difference is greater than or equal to the sum of the rated power, the CPU board controls the grid connection switch of the new energy power generation system to disconnect by controlling the corresponding trip output.

3. The automatic power control device for preventing reverse power loss according to claim 2, characterized in that, The input board is also connected to an external power source to provide operating power to the AC board, the output board, and the CPU board.

4. A new energy power generation system, characterized in that, Includes the anti-reverse power automatic control device as described in claim 2.

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