Optical storage all-in-one machine circuit based on double breakpoints and optical storage method

Abstract

The invention provides an optical storage all-in-one machine circuit based on double breakpoints and an optical storage method, a double-breakpoint control circuit is formed by a power grid contactor, an energy storage contactor, a power grid contact control module, an energy storage contact control module and an energy storage converter, the connection state of the power grid contactor is switched according to the power supply voltage state of an external power grid, and the power supply voltage state of the external power grid is switched. A power supply circuit is quickly cut off, current backflow is prevented, and accidents such as electric shock are avoided. The connection state of the energy storage contactor is adjusted through the energy storage contact control module, and isolation protection of the optical storage system is achieved. The connection state of the power supply network is accurately controlled through a light storage method based on double breakpoints, it is ensured that the light storage system and an external power grid can stably and efficiently work cooperatively under different working conditions, and the power supply requirement of a load is met; in addition, the double-breakpoint design conforms to stricter safety standards and specifications, and the competitiveness of the product in the international market is improved.

Description

Technical Field

[0001] The present invention belongs to the field of optical storage, and more specifically, discloses an integrated optical storage circuit and an optical storage method based on double breakpoints. Background Art

[0002] Photovoltaic and Energy Storage Integrated System (PV-ESS) is a comprehensive energy solution that combines photovoltaic power generation system and energy storage system. Thanks to the progress of solar photovoltaic technology, the maturity of battery energy storage technology and the increasing global demand for renewable energy and energy conservation and emission reduction, the market demand for PV-ESS is gradually increasing.

[0003] As different countries and regions have introduced policies to encourage the development of renewable energy, the overseas market for photovoltaic and storage devices has great development opportunities, driven not only by policy support and market demand, but also by technological innovation and increased awareness of environmental protection. However, unlike the domestic market, some overseas countries have grid-connected safety requirements for photovoltaic and storage devices, including double-breakpoint protection, which must meet the safety certification requirements of IEC62109-2. Therefore, it is necessary to design a protection technology for photovoltaic and storage devices based on double breakpoints to improve the safety of use. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a photovoltaic storage integrated circuit and photovoltaic storage method based on dual breakpoints, wherein a dual breakpoint control circuit is composed of a power grid contactor, an energy storage contactor, a power grid contact control module, an energy storage contact control module and an energy storage converter. According to the power supply voltage state of the external power grid, the connection state of the power grid contactor is switched to quickly cut off the power supply path to prevent current backflow, thereby avoiding accidents such as electric shock; the connection state of the energy storage contactor is adjusted by the energy storage contact control module to achieve isolation protection for the photovoltaic storage system; and the photovoltaic storage method based on dual breakpoints is used to accurately control the connection state of the power supply network to ensure that under different working conditions, the photovoltaic storage system and the external power grid can work together stably and efficiently to meet the power supply needs of the load; in addition, the dual breakpoint design meets more stringent safety standards and specifications, thereby improving the competitiveness of the product in the international market.

[0005] In order to achieve the above-mentioned object, the first aspect of the present invention provides a dual-breakpoint integrated optical storage circuit, wherein the dual-breakpoint integrated optical storage circuit: Grid contactor, energy storage contactor, grid contact control module, energy storage contact control module and energy storage converter; The grid contactor is a path switch used to switch the connection state between the external grid and the power supply network; The energy storage contactor is a path switch used to switch the connection state between the energy storage converter and the power supply network; The grid contact control module is a control circuit of a passage switch, and is used to control the conduction state of the grid contactor; The energy storage contact control module is a control circuit of a passage switch, which is used to control the conduction state of the energy storage contactor; The energy storage converter is a circuit for controlling energy exchange between the energy storage system and the power supply network, and switches the connection state with the power supply network through the energy storage contact control module.

[0006] This plan also includes: Static transfer switches, load switches and leakage detectors; The static transfer switch is used to detect the power supply voltage state of the external power grid and complete the process of connecting or disconnecting the external power grid with the power supply network; The load switch is used to switch the connection state between the load and the power supply network; The leakage detector is used to detect leakage current of the power supply network.

[0007] In this solution, the energy storage converter specifically includes: Three-phase three-level converter and energy storage system; The three-phase three-level converter includes a rectifier module and an inverter module; The rectifier module is used to convert three-phase alternating current into direct current for charging the energy storage system; The inverter module converts the direct current provided by the energy storage system into three-phase alternating current for use in an AC load or incorporated into a power supply network; The energy storage system is an energy storage battery, which is used to store and release electrical energy.

[0008] This plan also includes: The control circuit of the access switch is used to control the conductive state of the contactor electromagnetic coil according to the contact input signal; The contact input signal is a supply voltage of an external power grid or a control signal of the energy storage converter.

[0009] The second aspect of the present invention further provides a dual-breakpoint based optical storage method, which is applied to any of the above-mentioned dual-breakpoint based optical storage integrated circuits, and the method specifically includes: Obtain the external power supply status; When it is determined that the power supply state of the external power grid is a power-on state; Acquiring first voltage information; determining whether the first voltage information is in a stable state according to the amplitude of the first voltage information; If yes, obtaining first phase information according to the first voltage information; Determining whether the first phase information is a preset phase threshold; If so, the external power grid power supply state is set to the power supply state and switched to the grid-connected mode.

[0010] In this solution, judging whether the first voltage information is in a stable state according to the amplitude of the first voltage information is specifically: Acquire first cycle information of first voltage information; Obtain at least two voltage peak-to-peak values ​​information according to the first cycle information; Calculating the difference of the voltage peak-to-peak value information to obtain voltage difference information; Determining whether the voltage difference information is lower than a preset voltage difference threshold; If not, the first voltage information is in an unstable state; If yes, then according to the voltage peak-to-peak value information, the voltage amplitude of phase A, the voltage amplitude of phase B and the voltage amplitude of phase C are obtained; Obtaining deviation value information according to the A-phase voltage amplitude, the B-phase voltage amplitude and the C-phase voltage amplitude; Determining whether the deviation value information is lower than a preset deviation value threshold; If not, the first voltage information is in an unstable state; If so, the first voltage information is in a stable state.

[0011] In this solution, the first phase information is obtained according to the first voltage information, specifically: Determining whether the first voltage information reaches a preset first voltage threshold; If so, then the A phase time information, the B phase time information and the C phase time information are obtained in sequence; Obtaining A phase information, B phase information, and C phase information according to the first cycle information of the first voltage information and the A phase time information, the B phase time information, and the C phase time information; Obtaining first phase difference information, second phase difference information and third phase difference information according to the A phase information, the B phase information and the C phase information; Determining whether the first phase difference information, the second phase difference information, and the third phase difference information are equal; If so, the first phase information is set as first phase difference information; If not, the first phase information is set to 0.

[0012] This plan also includes: When it is determined that the external power grid power supply state is a power supply state; Acquire first power information; Determining whether the first power information is lower than a preset first power threshold; If yes, obtaining first current information; According to the first current information, determining whether the energy storage converter is switched to a charging state; If so, the energy storage converter is adjusted according to the first voltage information and the first phase information.

[0013] In this solution, judging whether the energy storage converter is switched to the grid charging state according to the first current information is specifically as follows: Acquiring first voltage information; Determining a first current threshold according to the first voltage information; Determining whether the first current information exceeds the first current threshold; If yes, disconnecting the energy storage contactor; If not, the energy storage contactor is closed to switch to the grid charging state.

[0014] This plan also includes: When it is determined that the external power grid power supply state is a power supply state; Acquire first power information; Determining whether the first power information exceeds a preset second power threshold; If so, the energy storage contactor is disconnected.

[0015] The present invention provides a photovoltaic-storage integrated circuit and a photovoltaic-storage method based on dual breakpoints. A dual breakpoint control circuit is composed of a power grid contactor, an energy storage contactor, a power grid contact control module, an energy storage contact control module and an energy storage converter. According to the power supply voltage state of the external power grid, the connection state of the power grid contactor is switched to quickly cut off the power supply path to prevent current backflow, thereby avoiding accidents such as electric shock; the connection state of the energy storage contactor is adjusted by the energy storage contact control module to achieve isolation protection for the photovoltaic-storage system; and the photovoltaic-storage method based on dual breakpoints is used to accurately control the connection state of the power supply network to ensure that under different working conditions, the photovoltaic-storage system and the external power grid can work together stably and efficiently to meet the power supply needs of the load; in addition, the dual breakpoint design meets more stringent safety standards and specifications, thereby improving the competitiveness of the product in the international market. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and should not be regarded as limiting the scope.

[0017] Figure 1 A connection diagram of a dual-breakpoint integrated optical storage circuit is shown; Figure 2 A circuit topology diagram of a dual-breakpoint integrated optical storage circuit provided by an embodiment of the present invention is shown; Figure 3 A circuit connection diagram of the energy storage converter provided in an embodiment of the present invention is shown; Figure 4 A schematic diagram of a double-breakpoint based light storage method is shown; Figure 5 A flowchart of detecting a stable state of first voltage information provided by an embodiment of the present invention is shown; Figure 6 A flow chart for confirming first phase information provided by an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] Unless otherwise defined, all terms (including technical and scientific terms) used in the embodiments of the present invention have the same meanings as commonly understood by those skilled in the art to which the present invention belongs. It should also be understood that terms such as those defined in common dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless the embodiments of the present invention are explicitly defined in this way.

[0020] The words "first", "second" and similar words used in the embodiments of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "one", "an" or "the" and similar words do not indicate a quantity limitation, but indicate the existence of at least one. Similarly, words such as "include" or "comprise" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The steps before or after the method of the embodiment of the present invention are not necessarily carried out in order. On the contrary, various steps can be processed in reverse order or simultaneously. At the same time, other operations can also be added to these processes, or a step or several steps can be removed from these processes.

[0021] Please refer to Figure 1 , Figure 1 A connection diagram of an integrated optical storage circuit based on double breakpoints is shown.

[0022] like Figure 1 As shown, the first aspect of the present invention discloses the optical storage integrated circuit based on double breakpoints, and the circuit includes: A grid contactor 101, an energy storage contactor 102, a grid contact control module 103, an energy storage contact control module 104 and an energy storage converter 107; The grid contactor is a path switch used to switch the connection state between the external grid and the power supply network; The energy storage contactor is a path switch used to switch the connection state between the energy storage converter and the power supply network; The grid contact control module is a control circuit of a passage switch, and is used to control the conduction state of the grid contactor; The energy storage contact control module is a control circuit of a passage switch, which is used to control the conduction state of the energy storage contactor; The energy storage converter is a circuit for controlling energy exchange between the energy storage system and the power supply network, and switches the connection state with the power supply network through the energy storage contact control module.

[0023] It should be noted that the external power grid 105 is an external AC power supply such as a mains power supply; the load 106 is a device that receives power from a power supply network, and the power supply network is a power supply line that provides power to the load.

[0024] The grid contactor 101 is a passage switch, including but not limited to a relay, an analog switch, etc., and is used to switch the connection state between the external power network and the power supply network by switching the state of the switch. The grid contact control module 103 is used to control the conduction state of the grid contactor. For example, when the grid contactor is a relay, the grid contact control module switches the power-on state of the relay coil to switch the relay switch.

[0025] The energy storage contactor 102 is a path switch, including but not limited to a relay, an analog switch, etc., and is used to switch the connection state between the external energy storage network and the power supply network by switching the state of the switch. The energy storage contact control module 104 is used to control the conduction state of the energy storage contactor. For example, when the energy storage contactor is a relay, the energy storage contact control module switches the power-on state of the relay coil to switch the relay switch.

[0026] The energy storage converter 107 is used for converting electric energy, including rectifying AC into DC for storage and inverting DC into AC for load power supply; that is, realizing the power supply network to supply power to the energy storage system, that is, charging the energy storage system, and realizing the energy storage system to supply power to the power supply network, that is, discharging the energy storage system. In addition, the energy storage converter also sends a control signal to the energy storage contact control module, and switches the connection state between the energy storage converter and the power supply network through the energy storage contact control module.

[0027] Please refer to Figure 2 , Figure 2 The circuit topology diagram of the optical storage integrated machine circuit based on double breakpoints provided by an embodiment of the present invention is shown.

[0028] According to an embodiment of the present invention, Figure 2 As shown, it also includes: Static transfer switch 201, bypass switch 202, load switch 203 and leakage detector 204; The static transfer switch is used to detect the power supply voltage state of the external power grid and complete the grid connection or disconnection process between the external power grid and the power supply network; The bypass switch is used to switch the connection state between the external power grid and the load; The load switch is used to switch the connection state between the load and the power supply network; The leakage detector is used to detect leakage current of the power supply network.

[0029] It should be noted that the static transfer switch is a circuit for voltage state detection and power supply network state switching, which can be used to detect the power supply state of the external power grid; when the power supply voltage of the external power grid reaches the preset voltage standard, the external power grid and the power supply network are connected through the switch; when the power supply voltage of the external power grid does not reach the preset voltage standard, the external power grid and the power supply network are disconnected through the switch. The bypass switch switches the conduction state of the bypass switch according to the bypass switch control signal. When it is in the conduction state, the external power grid can directly supply power to the load. The load switch switches the conduction state of the load switch according to the load switch control signal. When it is in the disconnected state, the load does not receive electrical energy from the power supply network. The leakage detector can detect leakage current in the power supply network; wherein, leakage current refers to non-functional current, which is an undesirable current that may cause safety hazards, including but not limited to semiconductor component leakage current, power supply leakage current, capacitor leakage current and filter leakage current.

[0030] Please refer to Figure 3 , Figure 3 A circuit connection diagram of the energy storage converter provided in an embodiment of the present invention is shown.

[0031] According to an embodiment of the present invention, Figure 3 As shown, the energy storage converter specifically includes: Three-phase three-level converter 301 and energy storage system 302; The three-phase three-level converter includes a rectifier module and an inverter module; The rectifier module is used to convert three-phase alternating current into direct current for charging the energy storage system; The inverter module converts the direct current provided by the energy storage system into three-phase alternating current for use in an AC load or incorporated into a power supply network; The energy storage system is an energy storage battery, which is used to store and release electrical energy.

[0032] It should be noted that the three-phase three-level converter is an energy converter of the integrated photovoltaic and energy storage device, which is used to convert three-phase alternating current into direct current and convert direct current into alternating current. The three-phase three-level converter includes at least a rectifier module and an inverter module. The rectifier module is used to convert three-phase alternating current into direct current for charging the energy storage system. The inverter module converts the direct current provided by the energy storage system into three-phase alternating current, which is used for the AC load 303 or incorporated into the power supply network. The energy storage system is an energy storage battery, which is used to store and release electrical energy.

[0033] According to an embodiment of the present invention, it also includes: The control circuit of the access switch is used to control the conductive state of the contactor electromagnetic coil according to the contact input signal; The contact input signal is a supply voltage of an external power grid or a control signal of the energy storage converter.

[0034] It should be noted that, as an implementation method, when the contactor is a relay, the control circuit of the passage switch switches the relay switch by switching the energized state of the relay coil according to the contact input signal. In practical applications, for the power grid contactor, the power supply voltage of the external power grid is used as the contact input signal; that is, when the external power grid is in normal power supply, the relay switch can be closed, and when the external power grid loses power, the relay switch is disconnected. For the energy storage contactor, the energy storage converter sends a corresponding control signal as the contact input signal; that is, the relay switch is turned on and off according to the control signal set by the energy storage converter.

[0035] Please refer to Figure 4 , Figure 4 A schematic diagram of a double-breakpoint based optical storage method is shown.

[0036] like Figure 4 As shown, the second aspect of the present invention discloses the optical storage method based on double breakpoints, and the method specifically includes: S402, obtaining the power supply status of the external power grid; S404, when it is determined that the power supply state of the external power grid is a power-on state; S408, obtaining first voltage information; S410, judging whether the first voltage information is in a stable state according to the amplitude of the first voltage information; S412, if yes, obtaining first phase information according to the first voltage information; S414, determining whether the first phase information is a preset phase threshold; S416: If yes, the external power grid power supply state is set to the power supply state and switched to the grid-connected mode.

[0037] It should be noted that the power restoration state refers to the state in which the external power grid changes from power failure to power supply, that is, the power supply is restored. At this time, the optical storage integrated machine needs to test the power supply voltage of the external power grid. Only when the power supply voltage of the external power grid meets the power supply requirements can the external power grid be incorporated into the power supply network, thereby avoiding external voltage damaging the power supply network or energy storage converter due to voltage instability, thereby improving the safety of the power supply network and energy storage converter.

[0038] The first voltage information is the power supply voltage of the external power grid, which is three-phase alternating current, including phase A voltage, phase B voltage and phase C voltage; the first phase information is the phase difference of the three-phase alternating current. In practical applications, the phase difference of the three-phase alternating current is required to be 120 degrees. The power supply state is the state in which the external power grid provides electric energy to the power supply network. The grid-connected mode is that the three-phase alternating current of the external power grid is connected to the power supply network or the energy storage converter according to the phase relationship; in addition, it also includes an off-grid mode, and the off-grid mode refers to the state in which the external power grid is disconnected from the power supply network.

[0039] In this embodiment, when the power supply state of the external power grid is the power restoration state, the stability of the power supply voltage and the correctness of the phase are checked to determine whether the power supply voltage of the external power grid meets the grid connection requirements, and the grid connection or off-grid operation is automatically performed according to the test results. First, according to the amplitude value of the first voltage information, it is determined whether the A-phase voltage, the B-phase voltage and the C-phase voltage have all reached the preset stable state; if so, the first phase is checked; if not, it means that at least one phase voltage of the A-phase voltage, the B-phase voltage and the C-phase voltage does not meet the power supply requirements, and there is a risk of damaging the power supply network or the energy storage converter if it is directly connected to the power supply network, so the off-grid state is maintained. Then, according to the phase relationship among the A-phase voltage, the B-phase voltage and the C-phase voltage, the first phase information is obtained to determine whether the first phase information is a preset phase threshold. In practical applications, it is determined whether the first phase information is 120 degrees. If so, it indicates that the phase of the first voltage information meets the power supply requirements of the three-phase alternating current. At this time, the power supply status of the external power grid is set to the power supply status, and switched to the grid-connected mode to realize the external power grid supplying power to the power supply network. If not, it indicates that the current three-phase alternating current does not meet the grid-connected requirements, and the off-grid state continues to be maintained.

[0040] Please refer to Figure 5 , Figure 5 A flow chart for detecting a stable state of first voltage information provided by an embodiment of the present invention is shown.

[0041] In the embodiment of the present invention, Figure 5 As shown, judging whether the first voltage information is in a stable state according to the amplitude of the first voltage information is specifically: S502, obtaining first cycle information of first voltage information; S504, obtaining at least two voltage peak-to-peak values ​​information according to the first cycle information; S506, calculating the difference of the voltage peak-to-peak value information to obtain voltage difference information; S508, determining whether the voltage difference information is lower than a preset voltage difference threshold; S510, if not, the first voltage information is in an unstable state; S512, if yes, then obtain the A phase voltage amplitude, the B phase voltage amplitude and the C phase voltage amplitude according to the voltage peak-to-peak value information; S514, obtaining deviation value information according to the A-phase voltage amplitude, the B-phase voltage amplitude, and the C-phase voltage amplitude; S516, determining whether the deviation value information is lower than a preset deviation value threshold; S510, if not, the first voltage information is in an unstable state; S518: If yes, the first voltage information is in a stable state.

[0042] It should be noted that the first cycle information is the AC cycle of the first voltage information; the voltage peak-to-peak value is the difference between the high-level voltage and the low-level voltage recognized by the first voltage information in the same AC cycle, which is used to represent the voltage value of the first voltage information in an AC cycle; the voltage difference information is the deviation value of the voltage value of the first voltage information in different AC cycles; the deviation information is the deviation value between the A-phase voltage amplitude, the B-phase voltage amplitude and the C-phase voltage amplitude obtained according to the set deviation value calculation method; the stable state means that the power supply voltage of the external power grid meets the power supply network's supply stability requirements for three-phase AC power; the stable state means that the power supply voltage of the external power grid does not meet the power supply network's supply stability requirements for three-phase AC power.

[0043] In this embodiment, the first voltage information is determined to be in a stable state only when the voltage amplitude of each phase of the three-phase alternating current is in a recognized stable state and the difference between the voltage amplitudes of each phase is within a set difference range. First, the peak-to-peak values ​​of the A-phase voltage, the B-phase voltage and the C-phase voltage are detected respectively according to the AC cycle of the first voltage information. The peak-to-peak values ​​of at least two voltages of the same phase are obtained for difference calculation to obtain voltage difference information. When the voltage difference information of any one of the A-phase, B-phase or C-phase voltages is not lower than the preset voltage difference threshold, it is determined that the first voltage information is in an unstable state. When the voltage difference of the A-phase voltage, the B-phase voltage and the C-phase voltage are all lower than the preset voltage difference threshold, it means that the amplitude change of each phase voltage is small, meeting the stability requirements of the phase voltage. Then, when the A-phase voltage, the B-phase voltage and the C-phase voltage amplitude meet the stability requirements, the corresponding phase voltage amplitude is obtained according to the peak-to-peak value of each phase voltage. The mean of the three phase voltage amplitudes is calculated, and then the deviation value information is obtained according to the arithmetic sum of the differences between the three phase voltage amplitudes and the mean. Finally, determine whether the deviation value information is lower than the preset deviation value threshold; if not, it means that the amplitude deviation of phase A voltage, phase B voltage and phase C voltage is large, and it is determined that the first voltage information is in an unstable state; if yes, it means that the amplitude deviation of phase A voltage, phase B voltage and phase C voltage is small, and it can be determined that the first voltage information is in a stable state.

[0044] Please refer to Figure 6 , Figure 6 A flow chart for confirming first phase information provided by an embodiment of the present invention is shown.

[0045] In the embodiment of the present invention, Figure 6 As shown, the first phase information is obtained according to the first voltage information, specifically: S602, determining whether the first voltage information reaches a preset first voltage threshold; S604, if yes, then obtain the A phase time information, the B phase time information and the C phase time information in sequence; S606, obtaining A phase phase information, B phase phase information, and C phase phase information according to the first cycle information of the first voltage information and the A phase time information, the B phase time information, and the C phase time information; S608, obtaining first phase difference information, second phase difference information and third phase difference information according to the A phase information, the B phase information and the C phase information; S610, determining whether the first phase difference information, the second phase difference information, and the third phase difference information are equal; S612: If yes, the first phase information is set as first phase difference information; S614: If not, the first phase information is set to 0.

[0046] It should be noted that, as an implementation method, the first phase information is obtained by zero-crossing detection. First, the time when the three phase voltages reach the set zero voltage is recorded, which is recorded as the A-phase time information, the B-phase time information and the C-phase time information. Secondly, in combination with the AC cycle of the first voltage information, the A-phase phase information, the B-phase phase information and the C-phase phase information are obtained; as an implementation method, the duration of the AC cycle is represented as 360 degrees, and the corresponding phase angle is obtained according to the position of the A-phase time information, the B-phase time information and the C-phase time information in the AC cycle as the phase information. Then, according to the difference in phase information of each two phase voltages, the phase difference information is obtained; as an implementation method, the difference between the A-phase phase information and the B-phase phase information is calculated to obtain the first phase difference information, the difference between the B-phase phase information and the C-phase phase information is calculated to obtain the second phase difference information, and the difference between the C-phase phase information and the A-phase phase information is calculated to obtain the third phase difference information. Finally, determine whether the first phase difference information, the second phase difference information and the third phase difference information are equal; if so, it means that the phase difference of the three phase voltages is uniform, which meets the phase requirement of the power supply network for the three-phase alternating current. At this time, the first phase information is set to the first phase difference information; if not, it means that the phase difference of the three phase voltages is uneven. At this time, the first phase information is set to 0, which is used to indicate that the phase of the three-phase alternating current does not meet the power supply requirement.

[0047] In an embodiment of the present invention, it also includes: When it is determined that the external power grid power supply state is a power supply state; Acquire first power information; Determining whether the first power information is lower than a preset first power threshold; If yes, obtaining first current information; According to the first current information, determining whether the energy storage converter is switched to a charging state; If so, the energy storage converter is adjusted according to the first voltage information and the first phase information.

[0048] It should be noted that the first current information is the leakage current value in the power supply network measured by the leakage detector; the first power information is the power value of the energy storage system. In this embodiment, the power supply state of the external power grid is the power supply state. If the power value of the energy storage system is too low, it is necessary to first detect and judge the leakage current of the power supply network before the energy storage system can be charged through the external power grid to improve the safety of the energy storage system. When the power supply state of the external power grid is the power supply state, and the first power information of the energy storage system is lower than the preset first power threshold, the leakage current of the power supply network, that is, the first current information, is detected by the leakage detector. When the first current information is lower than the set current threshold, it means that the energy storage system can be switched to the charging state. At this time, according to the amplitude of the first voltage information and the first phase information, the working parameters of the rectifier module of the energy storage converter are set for charging the energy storage system.

[0049] In an embodiment of the present invention, judging whether the energy storage converter is switched to a grid charging state according to the first current information is specifically: Acquiring first voltage information; Determining a first current threshold according to the first voltage information; determining whether the first current information exceeds the first current threshold; If yes, disconnecting the energy storage contactor; If not, the energy storage contactor is closed to switch to the grid charging state.

[0050] It should be noted that in this embodiment, the upper limit of the allowable leakage current, i.e., the first current threshold, is determined according to the power supply voltage amplitude of the external power grid to determine whether the energy storage converter is switched to the power grid charging state. It is determined whether the first current information exceeds the first current threshold; if so, it means that the leakage current of the power supply network is too high, and there is a risk of damaging the energy storage system if charging is performed. Therefore, the energy storage converter is disconnected from the power supply network by disconnecting the energy storage contactor; if not, it means that the leakage current of the power supply network is within the set safety range, and the energy storage converter is connected to the power supply network by closing the energy storage contactor, and the state of switching to the power grid charging is achieved, that is, the energy storage system is charged through the external power grid.

[0051] In an embodiment of the present invention, it also includes: When it is determined that the external power grid power supply state is a power supply state; Acquire first power information; Determining whether the first power information exceeds a preset second power threshold; If so, the energy storage contactor is disconnected.

[0052] It should be noted that in this embodiment, when the external power grid is in the power supply state, an overcharge protection rule is set. When the first power information of the energy storage system exceeds the preset second power threshold, it means that the power value of the energy storage system is in a high state. If it continues to be in the charging connection state, there is a problem of affecting the service life of the energy storage battery due to overcharging. At this time, the energy storage contactor is disconnected to disconnect the energy storage converter from the power supply network, thereby stopping the external power grid from charging the energy storage system.

[0053] It is worth mentioning that it also includes: When it is determined that the external power grid power supply state is a power supply state; Acquiring second voltage information; Determining whether the second voltage information is lower than a preset second voltage threshold; If yes, obtaining first power information; Determining whether the first power information is lower than a preset third power threshold; If so, the energy storage contactor is disconnected and the bypass switch is closed.

[0054] It should be noted that the second voltage information is the voltage that the external power grid supplies to the power supply network through the power grid contactor, that is, the voltage value on the output side of the power grid contactor. When the circuit elements such as the power grid contactor are abnormal, the voltage value output by the external power grid through the power grid contactor is lowered in amplitude. When the second voltage information is lower than the second voltage threshold, the power supply network is usually powered by the energy storage system. If the first power information of the energy storage system is also lower than the preset third power threshold at this time, indicating that the power storage system power can no longer meet the power demand of the power supply network, the energy storage converter is disconnected from the power supply network by disconnecting the energy storage contactor, and the bypass switch is closed, so that the external power supply directly provides emergency power to the power load, thereby improving the experience of power consumption.

[0055] It is worth mentioning that it also includes: acquiring second current information; Determining whether the second current information exceeds a preset second current threshold; If yes, the load switch is turned off.

[0056] It should be noted that the second current information is the load current of the power load. In this embodiment, when the second current information exceeds the preset second current threshold, it indicates that there is a risk of excessive load current due to a short circuit, etc. By disconnecting the load switch, the power supply network is disconnected from the load, thereby protecting the integrated photovoltaic storage device.

[0057] It is worth mentioning that it also includes: When the external power grid is under maintenance, the power grid contactor is disconnected; When the energy storage converter is in maintenance status, the energy storage contactor is disconnected.

[0058] It should be noted that when the external power grid or the energy storage converter needs to be repaired, in order to ensure sustainable power supply to the power supply network during the maintenance period, the contactor is disconnected to avoid accidental power-on due to misoperation, which may affect the safety of the maintenance personnel.

[0059] In summary, the present invention provides a photovoltaic storage integrated circuit and photovoltaic storage method based on dual breakpoints, wherein a dual breakpoint control circuit is composed of a power grid contactor, an energy storage contactor, a power grid contact control module, an energy storage contact control module and an energy storage converter. According to the power supply voltage state of the external power grid, the connection state of the power grid contactor is switched to quickly cut off the power supply path to prevent current backflow, thereby avoiding accidents such as electric shock; the connection state of the energy storage contactor is adjusted by the energy storage contact control module to achieve isolation protection for the photovoltaic storage system; and the photovoltaic storage method based on dual breakpoints is used to accurately control the connection state of the power supply network to ensure that under different working conditions, the photovoltaic storage system and the external power grid can work together stably and efficiently to meet the power supply needs of the load; in addition, the dual breakpoint design meets more stringent safety standards and specifications, thereby improving the competitiveness of the product in the international market.

[0060] In addition, the functional modules in the various embodiments of the present invention may be integrated together to form an independent part, or each module may exist independently, or two or more modules may be integrated to form an independent part.

[0061] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, and other media that can store program codes.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A dual-breakpoint integrated optical storage circuit, characterized in that: The optical storage integrated circuit based on double breakpoints includes: Grid contactor, energy storage contactor, grid contact control module, energy storage contact control module and energy storage converter; The grid contactor is a path switch used to switch the connection state between the external grid and the power supply network; The energy storage contactor is a path switch used to switch the connection state between the energy storage converter and the power supply network; The grid contact control module is a control circuit of a passage switch, and is used to control the conduction state of the grid contactor; The energy storage contact control module is a control circuit of a passage switch, which is used to control the conduction state of the energy storage contactor; The energy storage converter is a circuit for controlling energy exchange between the energy storage system and the power supply network, and switches the connection state with the power supply network through the energy storage contact control module.

2. The optical storage integrated circuit based on double breakpoints according to claim 1 is characterized in that: Also includes: Static transfer switches, load switches and leakage detectors; The static transfer switch is used to detect the power supply voltage state of the external power grid and complete the grid connection or disconnection process between the external power grid and the power supply network; The load switch is used to switch the connection state between the load and the power supply network; The leakage detector is used to detect leakage current of the power supply network.

3. The optical storage integrated circuit based on double breakpoints according to claim 1, characterized in that: The energy storage converter specifically comprises: Three-phase three-level converter and energy storage system; The three-phase three-level converter includes a rectifier module and an inverter module; The rectifier module is used to convert three-phase alternating current into direct current for charging the energy storage system; The inverter module converts the direct current provided by the energy storage system into three-phase alternating current for use in an AC load or incorporated into a power supply network; The energy storage system is an energy storage battery, which is used to store and release electrical energy.

4. The optical storage integrated circuit based on double breakpoints according to claim 1, characterized in that: Also includes: The control circuit of the access switch is used to control the conductive state of the contactor electromagnetic coil according to the contact input signal; The contact input signal is a supply voltage of an external power grid or a control signal of the energy storage converter.

5. A dual-breakpoint based light storage method, applied to the dual-breakpoint based light storage integrated circuit according to any one of claims 1 to 4, characterized in that: The method specifically comprises: Obtain the external power supply status; When it is determined that the power supply state of the external power grid is a power-on state; Acquiring first voltage information; determining whether the first voltage information is in a stable state according to the amplitude of the first voltage information; If yes, obtaining first phase information according to the first voltage information; Determining whether the first phase information is a preset phase threshold; If so, the external power grid power supply state is set to the power supply state and switched to the grid-connected mode.

6. The optical storage method based on double breakpoints according to claim 5, characterized in that: The determining whether the first voltage information is in a stable state according to the amplitude of the first voltage information is specifically: Acquire first cycle information of first voltage information; Obtain at least two voltage peak-to-peak values ​​information according to the first cycle information; Calculating the difference of the voltage peak-to-peak value information to obtain voltage difference information; Determining whether the voltage difference information is lower than a preset voltage difference threshold; If not, the first voltage information is in an unstable state; If yes, then according to the voltage peak-to-peak value information, the voltage amplitude of phase A, the voltage amplitude of phase B and the voltage amplitude of phase C are obtained; Obtaining deviation value information according to the A-phase voltage amplitude, the B-phase voltage amplitude and the C-phase voltage amplitude; Determining whether the deviation value information is lower than a preset deviation value threshold; If not, the first voltage information is in an unstable state; If so, the first voltage information is in a stable state.

7. The optical storage method based on double breakpoints according to claim 5, characterized in that: The first phase information is obtained according to the first voltage information, specifically: Determining whether the first voltage information reaches a preset first voltage threshold; If so, then the A phase time information, the B phase time information and the C phase time information are obtained in sequence; Obtaining A phase information, B phase information, and C phase information according to the first cycle information of the first voltage information and the A phase time information, the B phase time information, and the C phase time information; Obtaining first phase difference information, second phase difference information and third phase difference information according to the A phase information, the B phase information and the C phase information; Determining whether the first phase difference information, the second phase difference information, and the third phase difference information are equal; If so, the first phase information is set as first phase difference information; If not, the first phase information is set to 0.

8. The optical storage method based on double breakpoints according to claim 5, characterized in that: Also includes: When it is determined that the external power grid power supply state is a power supply state; Acquire first power information; Determining whether the first power information is lower than a preset first power threshold; If yes, obtaining first current information; According to the first current information, determining whether the energy storage converter is switched to a charging state; If so, the energy storage converter is adjusted according to the first voltage information and the first phase information.

9. The optical storage method based on double breakpoints according to claim 8, characterized in that: The determining, based on the first current information, whether the energy storage converter is switched to a grid charging state is specifically: Acquiring first voltage information; Determining a first current threshold according to the first voltage information; determining whether the first current information exceeds the first current threshold; If yes, disconnecting the energy storage contactor; If not, the energy storage contactor is closed to switch to the grid charging state.

10. The method for storing solar energy based on double breakpoints according to claim 5, characterized in that: Also includes: When it is determined that the external power grid power supply state is a power supply state; Acquire first power information; Determining whether the first power information exceeds a preset second power threshold; If so, the energy storage contactor is disconnected.

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