inverter

Abstract

An inverter, comprising: a DC surge protection apparatus, a DC bus, an inverter circuit, a measurement apparatus, an AC surge protection apparatus, a measurement apparatus and a controller. A DC end of the inverter circuit is connected to a DC port of the inverter by means of the DC bus, and an AC end of the inverter circuit is connected to an AC port of the inverter. The measurement apparatuses are arranged in a surge loop of the inverter, and are configured to measure electrical parameters of the surge loop, the surge loop being a flow path of a surge current in the inverter. The controller is configured to control turn-off of switching devices in the inverter circuit when the electrical parameters measured by the measurement apparatuses satisfy a lightning surge condition, and turn on the DC surge protection apparatus and the AC surge protection apparatus after the switching devices are turned off.

Description

Inverter

[0001] Cross-references to related applications

[0002] This disclosure is based on and claims priority to Chinese Patent Application No. 202411614633.1, filed on November 12, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to an inverter, a control method, and a photovoltaic energy storage system. Background Technology

[0004] Due to the inverter's waveform timing, when the traditional reactance overcurrent signal is detected, the inverter's power semiconductors are turned off according to the timing. Before the power semiconductors are turned off, they have already carried a large current, which leads to overvoltage and current failure of the switching devices. Summary of the Invention

[0005] This disclosure aims to at least address one of the technical problems existing in the background art. To this end, this disclosure proposes an inverter, a control method, and a photovoltaic energy storage system that can improve the safety and reliability of the inverter.

[0006] This disclosure provides an inverter. According to one embodiment of this disclosure, the inverter includes a DC surge protection device, a DC bus, an inverter circuit, a detection device, an AC surge protection device, and a controller. The DC terminal of the inverter circuit is connected to the DC port of the inverter via the DC bus, and the AC terminal of the inverter circuit is connected to the AC port of the inverter. The detection device is configured to be located in the surge circuit of the inverter for detecting the electrical parameters of the surge circuit, which is the path for surge current within the inverter. The controller is configured to control the switching devices in the inverter circuit to turn off when the electrical parameters detected by the detection device meet the lightning surge conditions, and to activate the DC surge protection device and the AC surge protection device after the switching devices are turned off.

[0007] According to one embodiment of this disclosure, the detection device includes a first current detection component. The first current detection component is configured to be disposed at the positive and / or negative terminal of the DC port, for detecting current information at the positive or negative terminal of the DC port as the electrical parameter. The controller is configured to control the switching devices in the inverter circuit to turn off when at least one parameter of the current information at the positive and negative terminals of the DC port satisfies a lightning surge condition.

[0008] According to one embodiment of this disclosure, the DC port includes a positive terminal and a negative terminal. The positive terminal is configured to be connected to the positive terminal of a DC source, and the negative terminal is configured to be connected to the negative terminal of a DC source. The positive terminal of the DC port is connected to the positive terminal of the connection, and the negative terminal of the DC port is connected to the negative terminal of the connection. A first current detection component is configured to be connected in series with the positive terminal of the connection to detect the current flowing through the positive terminal of the connection as an electrical parameter, and / or the first current detection component is configured to be connected in series with the negative terminal of the connection to detect the current flowing through the negative terminal of the connection as an electrical parameter. The controller is configured to control the switching devices in the inverter circuit to turn off when at least one parameter of the current flowing through the positive terminal of the connection and the current flowing through the negative terminal of the connection satisfies the lightning surge condition.

[0009] According to one embodiment of this disclosure, the DC port includes multiple positive terminals and multiple negative terminals. Each positive terminal is configured to connect to a corresponding positive DC source, and each negative terminal is configured to connect to a corresponding negative DC source. The positive terminal of the DC port is connected to the multiple positive terminals and connected to multiple positive DC sources through the multiple positive terminals. The negative terminal of the DC port is connected to the multiple negative terminals and connected to multiple negative DC sources through the multiple negative terminals. The first current detection component includes multiple first current detection elements and second current detection elements. Each first current detection element is configured to be connected in series with any one of the positive and / or negative terminals to detect the current flowing through any one of the positive and / or negative terminals as the electrical parameter. The second current detection element is configured to be disposed at the positive and / or negative terminals of the DC port to detect the total current flowing through the multiple positive terminals and / or the total current flowing through the multiple negative terminals as the electrical parameter. The controller is configured to control each switching device in the inverter circuit to turn off when at least one of the following parameters—the current flowing through any one of the positive terminals, the current flowing through any one of the negative terminals, the total current flowing through multiple positive terminals, and the total current flowing through multiple negative terminals—satisfies the lightning surge condition.

[0010] According to one embodiment of this disclosure, the detection device includes a first voltage detection component. The first voltage detection component is configured to be disposed at the positive and / or negative terminal of the DC port, for detecting voltage information at the positive and / or negative terminals of the DC port as the electrical parameters. The controller is configured to control the switching devices in the inverter circuit to turn off when at least one parameter of the voltage information at the positive and negative terminals of the DC port satisfies a lightning surge condition.

[0011] According to one embodiment of this disclosure, the first voltage detection component is connected in parallel between the positive and negative terminals of the DC port. The first voltage detection component is used to detect the voltage difference between the positive and negative terminals of the DC port as the electrical parameter. The controller is configured to control each switching device in the inverter circuit to turn off when the voltage difference between the positive and negative terminals of the DC port meets the lightning surge condition.

[0012] According to one embodiment of this disclosure, the detection device includes a second voltage detection component. The second voltage detection component is configured to be located at at least one of the positive, negative, or midpoint of the DC bus, for detecting voltage information at at least one of the positive, negative, or midpoint of the DC bus, as the electrical parameter. The controller is configured to control the switching devices in the inverter circuit to turn off when the voltage information at at least one of the positive, negative, or midpoint of the DC bus meets the lightning surge condition.

[0013] According to one embodiment of this disclosure, the second voltage detection component is connected in parallel between the positive and negative terminals of the DC bus, and is used to detect the voltage difference between the positive and negative terminals of the DC bus as an electrical parameter. Alternatively, the second voltage detection component is connected in parallel between the positive terminal and the midpoint of the DC bus, and is used to detect the voltage difference between the positive terminal and the midpoint of the DC bus as an electrical parameter. Or, the second voltage detection component is connected in parallel between the negative terminal and the midpoint of the DC bus, and is used to detect the voltage difference between the negative terminal and the midpoint of the DC bus as an electrical parameter. The controller is configured to control the switching devices in the inverter circuit to turn off when at least one of the following parameters—the voltage difference between the positive and negative terminals of the DC bus, the voltage difference between the positive terminal and the midpoint of the DC bus, and the voltage difference between the negative terminal and the midpoint of the DC bus—satisfies a lightning surge condition.

[0014] According to one embodiment of this disclosure, the detection device includes a second current detection component. The second current detection component is configured to be disposed in the connection line between the DC bus and the inverter circuit, for detecting current information in the connection line between the DC bus and the inverter circuit as the electrical parameter. The controller is configured to control the switching devices in the inverter circuit to turn off when at least one parameter in the current information of the connection line between the DC bus and the inverter circuit satisfies a lightning surge condition.

[0015] According to one embodiment of this disclosure, the positive terminal of the DC bus is connected to the DC terminal of the inverter circuit at a first node, the midpoint of the DC bus is connected to the DC terminal of the inverter circuit at a second node, and the negative terminal of the DC bus is connected to the DC terminal of the inverter circuit at a third node. A second current detection component is configured as a connection line between the positive terminal of the DC bus and the first node, for detecting the current flowing through the positive terminal of the DC bus and the first node; and / or the second current detection component is configured as a connection line between the midpoint of the DC bus and the second node, for detecting the current flowing through the midpoint of the DC bus and the second node; and / or the second current detection component is configured as a connection line between the negative terminal of the DC bus and the third node, for detecting the current flowing through the negative terminal of the DC bus and the third node. The controller is configured to control the switching devices in the inverter circuit to turn off when at least one of the following parameters—the current flowing between the positive terminal of the DC bus and the first node, the current flowing between the midpoint of the DC bus and the second node, and the current flowing between the negative terminal of the DC bus and the third node—satisfies the lightning surge condition.

[0016] According to one embodiment of this disclosure, the DC surge protection device is connected between the DC port and the ground electrode and is configured to connect the DC port and the ground electrode during startup. The detection device includes a third current detection component configured to be disposed between the connection line of the DC surge protection device and the ground electrode, for detecting the current flowing between the DC surge protection device and the ground electrode. The controller is configured to control the switching devices in the inverter circuit to turn off when the current flowing between the DC surge protection device and the ground electrode meets the lightning surge condition.

[0017] According to one embodiment of this disclosure, the AC surge protection device is connected between the AC port and the ground electrode and is configured to connect the AC port and the ground electrode during startup. The detection device includes a fourth current detection component configured to be disposed between the connection line of the AC surge protection device and the ground electrode, for detecting the current flowing between the AC surge protection device and the ground electrode. The controller is configured to control the switching devices in the inverter circuit to turn off when the current flowing between the AC surge protection device and the ground electrode meets the lightning surge condition.

[0018] According to one embodiment of this disclosure, the inverter includes an AC filter capacitor, a first terminal of which is connected to the AC port, and a second terminal of which is connected to the midpoint of the DC bus. The detection device includes a fifth current detection component configured to be connected in series with the AC filter capacitor for detecting the current flowing through the AC filter capacitor. The controller is configured to control the switching devices in the inverter circuit to turn off when the current flowing through the AC filter capacitor meets the lightning surge condition.

[0019] According to one embodiment of this disclosure, the AC port includes multiple AC connection terminals, the inverter includes multiple AC filter capacitors, a first terminal of each AC filter capacitor is connected to a corresponding AC connection terminal, and a second terminal of each AC filter capacitor is connected to a fourth node, the fourth node being connected to the midpoint of the DC bus. The fifth current detection component includes multiple third current detection elements and / or a fourth current detection element. Each third current detection element is configured to be connected in series with any one of the AC filter capacitors to detect the current flowing through any one of the AC filter capacitors, as the electrical parameter. The fourth current detection element is disposed between the fourth node and the midpoint of the DC bus to detect the total current flowing through the multiple AC filter capacitors, as the electrical parameter. The controller is configured to control the switching devices in the inverter circuit to turn off when at least one parameter, either the current flowing through any one of the AC filter capacitors or the total current flowing through the multiple AC filter capacitors, satisfies a lightning surge condition.

[0020] According to one embodiment of this disclosure, the DC port is connected to the input terminal of the transformer circuit, and the output terminal of the transformer circuit is connected to the DC bus. The detection device includes a sixth current detection component configured to be located at the input and / or output terminals of the transformer circuit, for detecting current information at the input and / or output terminals of the transformer circuit as electrical parameters. The controller is configured to control the switching devices in the inverter circuit to turn off when at least one parameter in the current information at the input or output terminal of the transformer circuit satisfies a lightning surge condition.

[0021] According to one embodiment of this disclosure, the sixth current detection component is configured to be connected in series with the input terminal of the transformer circuit to detect the current flowing through the input terminal of the transformer circuit as the electrical parameter, and / or the sixth current detection component is configured to be connected in series with the output terminal of the transformer circuit to detect the current flowing through the output terminal of the transformer circuit as the electrical parameter. The controller is configured to control the switching devices in the inverter circuit to turn off when at least one of the current flowing through the input terminal of the transformer circuit and the current flowing through the output terminal of the transformer circuit satisfies the lightning surge condition.

[0022] According to one embodiment of this disclosure, the controller is configured to: acquire electrical parameters of the surge circuit in the inverter; determine the surge current of the surge circuit based on the electrical parameters of the surge circuit; control each switching device in the inverter circuit to turn off before the current value of the surge current rises to a first preset current value; and activate the DC surge protection device and the AC surge protection device after each switching device is turned off.

[0023] This disclosure provides a control method for an inverter provided in an embodiment of this disclosure. The control method includes: when the electrical parameters detected by the detection device meet the lightning surge conditions, controlling each switching device in the inverter circuit to turn off, and after each switching device is turned off, activating the DC surge protection device and the AC surge protection device.

[0024] This disclosure provides a photovoltaic energy storage system, which includes the inverter described in the above embodiments.

[0025] The above-described one or more technical solutions in this disclosure have at least the following technical effects: the inverter can detect the electrical parameters of the surge circuit, and when the detected electrical parameters meet the lightning surge conditions, control each switching device in the inverter circuit to turn off, and after each switching device is turned off, activate the DC surge protection device and the AC surge protection device to ensure that each switching device is in the off state before overcurrent or overvoltage, avoiding overvoltage or overcurrent failure of the switching devices caused by high voltage and high current. Additional aspects and advantages of this disclosure will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this disclosure.

[0026] Brief description of the attached figures

[0027] The above and / or additional aspects and advantages of this disclosure will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0028] Figure 1 is a schematic diagram of an inverter provided in an embodiment of this disclosure;

[0029] Figure 2 is a schematic diagram of a lightning surge provided in an embodiment of this disclosure;

[0030] Figure 3 is a waveform diagram of the surge current provided in an embodiment of this disclosure;

[0031] Figure 4 is a schematic diagram of one of the detection devices provided in an embodiment of this disclosure;

[0032] Figure 5 is a schematic diagram of one of the detection devices provided in the embodiments of this disclosure;

[0033] Figure 6 is a schematic diagram of the location of the detection component in the related technology;

[0034] Figure 7 is a test waveform diagram of the detection device provided in an embodiment of this disclosure;

[0035] Figure 8 is a schematic diagram of one of the detection devices provided in an embodiment of this disclosure;

[0036] Figure 9 is a schematic diagram of one of the detection devices provided in an embodiment of this disclosure;

[0037] Figure 10 is a schematic diagram of one of the detection devices provided in the embodiments of this disclosure;

[0038] Figure 11 is a circuit diagram of an inverter provided in an embodiment of this disclosure;

[0039] Figure 12 is a circuit diagram of an inverter provided in an embodiment of this disclosure;

[0040] Figure 13 is a schematic diagram of one of the detection devices provided in an embodiment of this disclosure;

[0041] Figure 14 is one of the circuit diagrams of an inverter provided in an embodiment of this disclosure;

[0042] Figure 15 is a schematic diagram of one of the detection devices provided in the embodiments of this disclosure;

[0043] Figure 16 is a schematic diagram of one of the detection devices provided in an embodiment of this disclosure;

[0044] Figure 17 is a schematic diagram of one of the detection devices provided in the embodiments of this disclosure;

[0045] Figure 18 is a schematic diagram of one of the detection devices provided in an embodiment of this disclosure;

[0046] Figure 19 is a schematic diagram of a photovoltaic energy storage system provided in an embodiment of this disclosure.

[0047] Reference numerals: Inverter 100, DC port 110, positive connection terminal 111, negative connection terminal 112, AC port 120, AC connection terminal 121, DC bus 130, Inverter circuit 140, Transformer circuit 150, AC filter capacitor 160, Detection device 210, First current detection component 211, First current detection element 2111, Second current detection element 2112, First voltage detection component 212, Second voltage detection component 213, Second current detection component 214, Third current detection component 215, Fourth current detection component 216, Fifth current detection component 217, Third current detection element 2171, Fourth current detection element 2172, Sixth current detection component 218, Controller 220, DC surge protection device 230, AC surge protection device 240, Photovoltaic module 300, Photovoltaic energy storage system 1000. Specific Implementation

[0048] The technical solutions of the embodiments of this disclosure will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure are within the scope of protection of this disclosure.

[0049] The terms "first," "second," etc., used in this disclosure and in the claims are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this disclosure can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., can be of the same class, without limiting the number of objects; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0050] The inverter and photovoltaic power generation system provided in this disclosure will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0051] Due to the inverter's waveform timing, when the traditional reactance overcurrent signal is detected, the inverter's power semiconductors are usually turned off according to the timing. Before the power semiconductors are turned off, they have already carried a large current, which leads to overvoltage and current failure of the switching devices.

[0052] Because the power semiconductors, capacitors, and inductors in inverters are designed according to conventional voltage and current withstand requirements, the higher the inverter's operating voltage, the worse its surge protection capability. Surge protection devices are designed to protect the inverter under low-voltage or rated operating conditions. However, when the inverter's operating voltage is the system's maximum voltage, surge protection devices struggle to protect against lightning surges, which can easily lead to inverter failure and fires.

[0053] The bus voltage fluctuation can be reduced by increasing the capacitance of the film capacitor, or the voltage of the switching transistors in the module can be adjusted to a higher voltage (e.g., 1200V) to improve the inverter's surge protection capability. However, increasing the capacitance of the film capacitor or adjusting the voltage of the switching transistors in the module to 1200V is more expensive, increases inverter losses, and results in lower power conversion efficiency.

[0054] Referring to FIG1, this embodiment of the present disclosure provides an inverter 100, which may include a DC port 110, an AC port 120, a DC bus 130, an inverter circuit 140, a detection device 210, a controller 220, a DC surge protection device 230, and an AC surge protection device 240.

[0055] The DC terminal of inverter circuit 140 is connected to the DC port 110 of inverter 100 via DC bus 130, and the AC terminal of inverter circuit 140 is connected to the AC port of inverter 100. Detection device 210 is configured to be installed in the surge circuit of inverter 100 to detect the electrical parameters of the surge circuit, which is the path for surge current within inverter 100. Controller 220 is configured to turn off all switching devices in inverter circuit 140 when the electrical parameters detected by detection device 210 meet the lightning surge conditions, and to activate DC surge protection device 230 and AC surge protection device 240 after the switching devices are turned off.

[0056] This disclosure also provides a control method, which includes: when the electrical parameters detected by the detection device 210 meet the lightning surge conditions, controlling each switching device in the inverter circuit 140 to turn off, and after each switching device is turned off, activating the DC surge protection device 230 and the AC surge protection device 240.

[0057] In this embodiment, the detection device 210 may include a detection chip, detection circuit, sensor, resistor, transformer, or current transformer, or other devices capable of acquiring electrical parameters. The inverter 100 may include multiple connection lines and switching devices. The detection device 210 can detect the voltage of the connection lines and switching devices in the inverter 100, and can also detect the current flowing through the connection lines in the inverter 100, thereby obtaining the electrical parameters of different surge circuits within the inverter 100.

[0058] In this embodiment, the control method can be implemented by the controller 220, that is, the controller 220 is used to implement the control method. Of course, the control method can also be implemented by other devices or equipment, and is not limited to being implemented by the controller 220. The controller 220 may not be exclusively used to implement the control method of this embodiment, but may implement other functions or methods.

[0059] DC surge protection device 230 is configured to connect DC port 110 to ground, and connects DC port 110 to ground when all switching devices in the control inverter circuit 140 are turned off. When a surge current or voltage is suddenly generated in an electrical circuit or communication line due to external interference, DC surge protection device 230 can conduct and shunt the current in a very short time, thereby preventing the surge from damaging other equipment in the circuit.

[0060] The AC surge protection device 240 is configured to connect the AC port 120 to the ground, and connects the AC port 120 to the ground when all switching devices in the control inverter circuit 140 are turned off. When a surge current or voltage is suddenly generated in an electrical circuit or communication line due to external interference, the AC surge protection device 240 can conduct and shunt the current in a very short time, thereby preventing the surge from damaging other equipment in the circuit.

[0061] The surge current inside the inverter 100 flows through the surge loop formed by the corresponding connection lines and switching devices inside the inverter 100. Within the surge loop, the voltage and current parameters of the connection lines and switching devices correspond to the surge current of the inverter 100. This correspondence between the electrical parameters and the surge current within the surge loop can be obtained during the testing of the inverter 100. After determining the correspondence between the electrical parameters and the surge current within the surge loop, the controller 220 can determine the surge current based on the electrical parameters detected by the detection device 210, and thus determine whether the surge current meets the lightning surge conditions.

[0062] For example, during the testing of inverter 100, a preset external interference signal can be provided to inverter 100 to generate a test surge current at DC port 110 or AC port 120 of inverter 100. The current waveform diagram of the test surge current changing with time can be preset.

[0063] The detection device 210 can detect the electrical parameters of each surge circuit in the inverter 100 and obtain the waveform diagram of the electrical parameters of each surge circuit changing with time during the test of the inverter 100. Based on the current waveform diagram of the surge current changing with time and the waveform diagram of the electrical parameters of each surge circuit changing with time, the correspondence between the electrical parameters of each surge circuit in the inverter 100 and the surge current can be determined.

[0064] The correspondence between the electrical parameters and surge current of each surge circuit in inverter 100 is pre-set in the control program inside controller 220. This allows controller 220 to determine the magnitude of the surge current based on the correspondence between the electrical parameters and surge current of each surge circuit and the acquired electrical parameters. Based on the magnitude of the surge current, controller 220 determines whether the electrical parameters meet the lightning surge conditions. If the surge current reaches a preset current threshold, the electrical parameters are considered to meet the lightning surge conditions.

[0065] When the electrical parameters detected by the detection device 210 meet the lightning surge conditions, the controller 220 controls each switching device in the transformer circuit 150 to turn off. After each switching device is turned off, the DC surge protection device 230 and the AC surge protection device 240 are activated to ensure that each switching device is in the off state before overcurrent or overvoltage occurs, thus avoiding overvoltage or overcurrent failure of the switching devices caused by high voltage and high current.

[0066] In some embodiments, the controller 220 is configured to: acquire electrical parameters of the surge circuit within the inverter 100; determine the surge current of the surge circuit based on the electrical parameters of the surge circuit; control each switching device in the transformer circuit 150 to turn off before the surge current value rises to a first preset current value; and activate the DC surge protection device 230 and the AC surge protection device 240 after each switching device is turned off.

[0067] Taking Figure 3 as an example, in the initial stage of the surge current, the surge current value rises from zero. Node B represents the node where the surge current value rises to 90% of its maximum value, and node C represents the node where the surge current value rises to 10% of its maximum value. The time interval between nodes C and B is time interval T. Within time interval T, the surge current value rises at its maximum rate. A straight line L can be formed by connecting nodes C and B. Based on line L, the time it takes for the surge current to rise from zero to its maximum value can be determined as time T1.

[0068] In the middle of the surge current, the surge current value rises rapidly to its maximum value and then drops to zero. The time it takes for the surge current to rise from zero to its maximum value and then drop to 50% of its maximum value is time T2.

[0069] In the later part of the surge current, the current polarity is opposite to that in the earlier and middle parts of the surge current, and the maximum current value with the opposite polarity is 30% of the maximum current value.

[0070] The value of the first preset current can be set according to the maximum value of the surge current. The value of the first preset current can be set to 20%, 30%, 40%, 50%, 60%, 70%, 80% or 90% of the maximum value of the surge current.

[0071] The first preset current can also be set according to the actual situation. For example, when there are many switching devices, or when the voltage and current ratings of the switching devices are relatively small, the first preset current can be set to a relatively small value to ensure that each switching device is in the off state before overcurrent or overvoltage occurs. When the detection accuracy of the detection device 210 is relatively small, and the voltage and current ratings of the switching devices are relatively large, the first preset current can be set to a relatively large value to avoid the controller 220 frequently controlling the switching devices to turn off.

[0072] When the surge current in the surge circuit rises to the second preset current value, the controller 220 determines that the electrical parameters meet the lightning surge condition, and before it rises to the second preset current value, it determines that the electrical parameters meet the non-lightning surge condition.

[0073] The second preset current value is set smaller than the first preset current value to ensure that the controller 220 determines that the electrical parameters meet the lightning surge conditions before the surge current in the surge circuit rises to the first preset current value, and controls each switching device in the inverter circuit 140 to turn off.

[0074] In this way, the controller 220 can determine the surge current based on the detection device 210, and control the switching devices of the inverter 100 to turn off in advance based on the current value of the surge current, so as to avoid the switching devices from failing due to overvoltage or overcurrent caused by high voltage and high current.

[0075] Referring to Figure 4, in some embodiments, the detection device 210 includes a first current detection component 211. The first current detection component 211 is configured to be disposed at the positive or negative terminal of the DC port 110, for detecting the current information of the positive and / or negative terminals of the DC port 110 as electrical parameters. The controller 220 is configured to control the switching devices in the inverter circuit 140 to turn off when at least one parameter of the current information of the positive and negative terminals of the DC port 110 satisfies the lightning surge condition.

[0076] In this embodiment, the positive terminal of DC port 110 can be set as the PV+ terminal, and the negative terminal of DC port 110 can be set as the PV- terminal. DC port 110 can be connected to a DC source (such as a photovoltaic module), the PV+ terminal can be connected to the positive terminal of the DC source, and the PV- terminal can be connected to the negative terminal of the DC source. The surge current flow path within inverter 100 can include the connection lines flowing through the PV+ terminal and the PV- terminal. When external interference signals (such as lightning surges) affect inverter 100, surge current can flow through DC port 110, thereby affecting the current at the PV+ and PV- terminals.

[0077] The first current detection component 211 can be located at the PV+ terminal and detect the current flowing through the PV+ terminal as an electrical parameter. Alternatively, the first current detection component 211 can be located at the PV- terminal and detect the current flowing through the PV- terminal as an electrical parameter. Furthermore, the first current detection component 211 can be located at both the PV+ and PV- terminals and detect the current flowing through both terminals as electrical parameters.

[0078] During the testing of inverter 100, the correspondence between the surge current and the current flowing through the PV+ terminal, and the correspondence between the surge current and the current flowing through the PV- terminal, can be determined. During the testing of inverter 100, a preset external interference signal can be provided to inverter 100, causing the surge circuit within inverter 100 to generate a corresponding preset test surge current, and the location of the first current detection component 211 and the detected value are recorded. When the first current detection component 211 is located at the PV+ terminal, the correspondence between the current flowing through the PV+ terminal and the preset test surge current can be determined using the preset test surge current and the value detected by the first current detection component 211. When the first current detection component 211 is located at the PV- terminal, the correspondence between the current flowing through the PV- terminal and the preset test surge current can be determined using the preset test surge current and the value detected by the first current detection component 211.

[0079] The correspondence between the current flowing through the PV+ terminal and the preset test surge current, and the correspondence between the current flowing through the PV- terminal and the preset test surge current, can be preset in the control program inside the controller 220. This allows the controller 220 to determine the surge current based on the position of the first current detection component 211 and the detected current. Before the surge current rises to the first preset current value, the controller 220 can determine that the electrical parameters meet the lightning surge conditions based on the surge current and control the switching devices in the inverter circuit 140 to turn off.

[0080] Thus, the controller 220 can determine the shutdown of each switching device of the inverter circuit 140 based on the position of the first current detection component 211 and the detected current.

[0081] Referring to Figure 4, in some embodiments, the DC port 110 includes a positive terminal 111 and a negative terminal 112. The positive terminal 111 is configured to be connected to the positive terminal of a DC source, and the negative terminal 112 is configured to be connected to the negative terminal of a DC source. The positive terminal of the DC port 110 is connected to the positive terminal 111, and the negative terminal of the DC port 110 is connected to the negative terminal 112. A first current detection component 211 is configured to be connected in series with the positive terminal 111 to detect the current flowing through the positive terminal 111 as an electrical parameter, and / or the first current detection component 211 is configured to be connected in series with the negative terminal 112 to detect the current flowing through the negative terminal 112 as an electrical parameter. The controller 220 is configured to control the switching devices in the inverter circuit to turn off when at least one parameter of the current flowing through the positive terminal 111 and the current flowing through the negative terminal 112 meets the lightning surge condition.

[0082] In this embodiment, the positive terminal 111 can be designated as the PV1+ terminal, and the negative terminal 112 can be designated as the PV1- terminal. The positive terminal of the DC source can be connected to the PV+ terminal via the PV1+ terminal, and the negative terminal of the DC source can be connected to the PV- terminal via the PV1- terminal. The surge current flow path within the inverter 100 can include the connection lines between the PV1+ terminals and the connection lines between the PV1- terminals and the PV- terminals. When external interference signals (such as lightning surges) affect the inverter 100, the surge current can flow through the connection lines between the PV1+ terminals and the PV1- terminals and the PV- terminals.

[0083] The first current detection component 211 can be installed in the connection line between PV1+ and PV1+ terminals, and detect the current flowing through PV1+ and PV1+ terminals as an electrical parameter. The first current detection component 211 can also be installed in the connection line between PV1- and PV1- terminals, and detect the current flowing through PV1- and PV1- terminals as an electrical parameter. Furthermore, the first current detection component 211 can be installed in both the connection lines between PV1+ and PV1+ terminals and the connection lines between PV1- and PV1- terminals, and detect the current flowing through both PV1+ and PV1+ terminals as electrical parameters.

[0084] During the testing of inverter 100, the correspondence between the surge current and the current flowing through PV+ and PV1+ terminals, as well as the correspondence between the surge current and the current flowing through PV- and PV1- terminals, can be determined. When the first current detection component 211 is installed in the connection line between PV1+ and PV1+ terminals, the correspondence between the current flowing through PV+ and PV1+ terminals and the preset test surge current can be determined using a preset test surge current and the value detected by the first current detection component 211. Similarly, when the first current detection component 211 is installed in the connection line between PV- and PV1- terminals, the correspondence between the current flowing through PV- and PV1- terminals and the preset test surge current can be determined using a preset test surge current and the value detected by the first current detection component 211.

[0085] The correspondence between the current flowing through the PV+ and PV1+ terminals and the preset test surge current, as well as the correspondence between the current flowing through the PV- and PV1- terminals and the preset test surge current, can be preset in the control program inside the controller 220. This allows the controller 220 to determine the surge current based on the position of the first current detection component 211 and the detected current. Before the surge current rises to the first preset current value, the controller 220 can determine that the electrical parameters meet the lightning surge conditions based on the surge current and control the switching devices in the inverter circuit 140 to turn off.

[0086] Referring to Figure 5, in some embodiments, the DC port 110 includes multiple positive terminals 111 and multiple negative terminals 112. Each positive terminal 111 is configured to connect to a corresponding positive DC source, and each negative terminal 112 is configured to connect to a corresponding negative DC source. The positive terminal of the DC port 110 is connected to the multiple positive terminals 111 and connected to multiple positive DC sources through the multiple positive terminals 111. The negative terminal of the DC port 110 is connected to the multiple negative terminals 112 and connected to multiple negative DC sources through the multiple negative terminals 112. The first current detection component 211 includes multiple first current detection elements 2111 and second current detection elements 2112. Each first current detection element 2111 is configured to be connected in series with any one positive terminal 111 and / or any one negative terminal 112, for detecting the current flowing through any one positive terminal 111 and / or any one negative terminal 112 as an electrical parameter. The second current sensing element 2112 is configured to be located at the positive and / or negative terminal of the DC port 110, for detecting the total current flowing through the multiple positive terminals 111 and / or the total current flowing through the multiple negative terminals 112, as electrical parameters. The controller is configured to control the switching devices in the inverter circuit to turn off when at least one of the following parameters—the current flowing through any one positive terminal 111, the current flowing through any one negative terminal 112, the total current flowing through the multiple positive terminals 111, and the total current flowing through the multiple negative terminals 112—satisfies the lightning surge condition.

[0087] In this embodiment, the PV1+ terminal can be configured as a positive terminal 111 and connected to a positive DC source. The PV2+ terminal can be configured as another positive terminal 111 and connected to another positive DC source. The PV+ terminal can be connected to a positive DC source through the PV1+ terminal, and the PV+ terminal can also be connected to another positive DC source through the PV2+ terminal. The PV1- terminal can be configured as a negative terminal 112 and connected to a negative DC source. The PV2- terminal can be configured as another negative terminal 112 and connected to another negative DC source. The PV- terminal can be connected to a negative DC source through the PV1- terminal, and the PV- terminal can also be connected to another negative DC source through the PV2- terminal. The surge current flow path within the inverter 100 can include the connection lines between the PV1+ terminals, the connection lines between the PV2+ terminals, the connection lines between the PV1- terminals and the PV- terminals, and the connection lines between the PV2- terminals and the PV- terminals.

[0088] The first current sensing element 2111 can be installed in the connection line between PV1+ and PV+ terminals, and detect the current flowing through PV1+ and PV+ terminals as an electrical parameter. The first current sensing element 2111 can also be installed in the connection line between PV2+ and PV+ terminals, and detect the current flowing through PV2+ and PV+ terminals as an electrical parameter. The first current sensing element 2111 can also be installed in the connection line between PV1- and PV- terminals, and detect the current flowing through PV1- and PV- terminals as an electrical parameter. The first current sensing element 2111 can also be installed in the connection line between PV2- and PV- terminals, and detect the current flowing through PV2- and PV- terminals as an electrical parameter.

[0089] The first current sensing element 2111 can also be set in the connection line between PV1+ and PV1+ and the connection line between PV1- and PV1-, and detect the current flowing through PV1+ and PV1+ and the current flowing through PV1- and PV1- as electrical parameters.

[0090] The second current sensing element 2112 can be located at the PV+ terminal. The PV+ terminal is connected to both the PV1+ and PV2+ terminals. The current detected by the second current sensing element 2112 is the sum of the currents flowing through the PV+ and PV1+ terminals and the currents flowing through the PV+ and PV2+ terminals. Alternatively, the second current sensing element 2112 can be located at the PV- terminal. The PV- terminal is connected to both the PV1- and PV2- terminals. The second current sensing element 2112 can detect the currents flowing through the PV- and PV1- terminals and the total current flowing through the PV- and PV2- terminals as electrical parameters. The second current sensing element 2112 can also be located at both the PV+ and PV- terminals, detecting the currents flowing through the PV- and PV1- terminals, the total current flowing through the PV- and PV2- terminals, and the currents flowing through the PV+ and PV1+ terminals and the total current flowing through the PV+ and PV2+ terminals as electrical parameters.

[0091] If a certain first current detection element 2111 fails to work properly, the corresponding electrical parameters can be calculated and determined by other first current detection elements 2111 and second current detection elements 2112, thereby improving the accuracy of the detection parameters of the first current detection component 211.

[0092] If the current flowing through the PV+ and PV1+ terminals detected by the first current detection element 2111 is inaccurate, the current flowing through the PV+ and PV1+ terminals can be determined based on the sum of the current flowing through the PV+ and PV2+ terminals detected by the second current detection element 2112 and the current flowing through the PV+ and PV2+ terminals, as well as the current flowing through the PV+ and PV2+ terminals detected by the first current detection element 2111.

[0093] Inverter 100 can be tested to determine the correspondence between surge current and current flowing through PV+ and PV1+ terminals, surge current and current flowing through PV+ and PV2+ terminals, current flowing through PV- and PV1- terminals, and surge current and current flowing through PV- and PV2- terminals.

[0094] The correspondences between surge current and the current flowing through PV+ and PV1+ terminals, the surge current and the current flowing through PV+ and PV2+ terminals, the surge current and the current flowing through PV- and PV1- terminals, and the surge current and the current flowing through PV- and PV2- terminals can be preset in the control program within the controller 220. This allows the controller 220 to determine the surge current based on the position of the first current detection element 2111 and the detected current. Before the surge current rises to the first preset current value, the controller 220 can determine that the electrical parameters meet the lightning surge conditions based on the surge current and control the switching devices in the inverter circuit 140 to turn off.

[0095] Thus, if a certain first current detection element 2111 fails to work properly, the corresponding electrical parameters can be calculated and determined by other first current detection elements 2111 and second current detection elements 2112, thereby improving the accuracy of the detection parameters of the first current detection component 211.

[0096] In related technologies, referring to Figure 6, a detection component can be positioned between the AC port 120 and the grid connection point. It can control the switching devices in the inverter circuit 140 to turn off based on the current flowing through the AC port 120 connected to the grid. During the testing of the inverter 100, a preset external interference signal can be provided to the inverter 100, causing a test surge current to be generated at the AC port 120. The waveform of this surge current changing over time can be pre-set. The detection component positioned at the AC port 120 can detect the output current of the AC port 120, obtaining the waveform of the current changing over time detected by the detection component at the AC port 120 during the inverter 100 testing process.

[0097] Referring to Figure 7, the CTr waveform is a waveform diagram showing the change of current over time detected by the detection component located at AC port 120. Based on the CTr waveform, it can be determined that during the testing of inverter 100, the response speed of the detection component located at AC port 120 is relatively slow, indicating that the electrical parameters detected by the detection component at AC port 120 meet the lightning surge conditions relatively late.

[0098] In the inverter 100 provided in this embodiment, the electrical parameters detected by the detection device 210 meet the lightning surge conditions earlier than the electrical parameters detected by the detection component set at the AC port 120 meet the lightning surge conditions. The controller 220 can control the switching devices in the inverter circuit 140 to turn off in advance.

[0099] Referring to Figure 8, in some embodiments, the detection device 210 includes a first voltage detection component 212. The first voltage detection component 212 is configured to be located at the positive or negative terminal of the DC port 110, and is used to detect the voltage information of the positive or negative terminal of the DC port 110 as an electrical parameter. The controller 220 is configured to control the switching devices in the inverter circuit 140 to turn off when at least one parameter of the voltage information of the positive and negative terminals of the DC port 110 satisfies the lightning surge condition.

[0100] In this embodiment, the positive terminal of DC port 110 can be set as PV+ terminal, and the negative terminal of DC port 110 can be set as PV- terminal. The surge current flow path within inverter 100 can include the connection lines flowing through PV+ terminal and PV- terminal. When external interference signals (such as lightning surges) affect inverter 100, surge current can flow through PV+ terminal and PV- terminal, thereby affecting the voltage of PV+ terminal and PV- terminal.

[0101] The first voltage detection component 212 can be located at the PV+ terminal and detect the voltage at the PV+ terminal as an electrical parameter. Alternatively, the first voltage detection component 212 can be located at the PV- terminal and detect the voltage at the PV- terminal as an electrical parameter.

[0102] Inverter 100 can be tested to determine the correspondence between inrush current and the voltage at the PV+ terminal, and the correspondence between inrush current and the voltage at the PV- terminal. During the testing of inverter 100, a preset external interference signal can be provided to inverter 100, causing the surge circuit within inverter 100 to generate a corresponding preset test inrush current, and the location of the first voltage detection component 212 and the detected value are recorded. When the first voltage detection component 212 is located at the PV+ terminal, the correspondence between the voltage at the PV+ terminal and the preset test inrush current can be determined using the preset test inrush current and the value detected by the first voltage detection component 212. When the first voltage detection component 212 is located at the PV- terminal, the correspondence between the voltage at the PV- terminal and the preset test inrush current can be determined using the preset test inrush current and the value detected by the first voltage detection component 212.

[0103] The correspondence between the voltage at the PV+ terminal and the preset test surge current, and the correspondence between the voltage at the PV- terminal and the preset test surge current, can be preset in the control program inside the controller 220. This allows the controller 220 to determine the surge current based on the position of the first voltage detection component 212 and the detected voltage. Before the surge current rises to the first preset voltage value, the controller 220 can determine that the electrical parameters meet the lightning surge conditions based on the surge current and control the switching devices in the inverter circuit 140 to turn off.

[0104] Thus, the controller 220 can determine the switching devices of the inverter circuit 140 to be turned off based on the voltage information of the DC port 110.

[0105] Referring to Figure 7, the PV voltage waveform corresponds to the waveform diagram of the electrical parameters detected by the first voltage detection component 212 changing over time. Based on the PV voltage waveform, it can be determined that during the test of the inverter 100, the first voltage detection component 212 responds quickly, indicating that the electrical parameters detected by the first voltage detection component 212 meet the lightning surge conditions earlier. Therefore, the controller 220 can control the switching devices in the inverter circuit 140 to turn off in advance.

[0106] Referring to Figure 8, in some embodiments, a first voltage detection component 212 is connected in parallel between the positive and negative terminals of the DC port 110. The first voltage detection component 212 is used to detect the voltage difference between the positive and negative terminals of the DC port 110 as an electrical parameter. The controller 220 is configured to control the switching devices in the inverter circuit 140 to turn off when the voltage difference between the positive and negative terminals of the DC port 110 meets the lightning surge condition.

[0107] In this embodiment, when an external interference signal (such as a lightning surge) affects the inverter 100, the surge current can flow through the PV+ terminal and the PV- terminal, thereby affecting the voltage difference between the PV+ terminal and the PV- terminal. The first voltage detection component 212 is connected in parallel between the PV+ terminal and the PV- terminal, and detects the voltage difference between the PV+ terminal and the PV- terminal as an electrical parameter.

[0108] During the testing of inverter 100, a preset external interference signal can be provided to inverter 100 to generate a corresponding preset test surge current in the surge circuit inside inverter 100. The waveform of the voltage value detected by the first voltage detection component 212 over time is recorded to determine the correspondence between the surge current and the voltage difference between PV+ and PV- terminals.

[0109] The correspondence between the surge current and the voltage difference between the PV+ and PV- terminals can be preset in the control program inside the controller 220, so that the controller 220 can determine the surge current based on the position of the first voltage detection component 212 and the detected voltage.

[0110] Thus, the controller 220 can determine the shutdown of each switching device in the inverter circuit 140 based on the voltage difference between the positive and negative terminals of the DC port 110.

[0111] Referring to Figure 9, the detection device 210 includes a second voltage detection component 213. The second voltage detection component 213 is configured to be located at at least one of the positive, negative, or midpoint of the DC bus 130, and is used to detect voltage information at at least one of the positive, negative, or midpoint of the DC bus 130 as an electrical parameter. The controller 220 is configured to control the switching devices in the inverter circuit 140 to turn off when the voltage information at at least one of the positive, negative, or midpoint of the DC bus 130 meets the lightning surge condition.

[0112] In this embodiment, the surge current flow path within the inverter 100 may include a connection line flowing through the positive terminal of the DC bus 130, a connection line flowing through the negative terminal of the DC bus 130, and a connection line flowing through the midpoint of the DC bus 130. When an external interference signal (such as a lightning surge) affects the inverter 100, the surge current can flow through the positive, midpoint, and negative terminals of the DC bus 130, thereby affecting the voltage of the positive, midpoint, and negative terminals of the DC bus 130.

[0113] The second voltage detection component 213 can be installed at the positive terminal of the DC bus 130 and detect the voltage at the positive terminal of the DC bus 130 as an electrical parameter. The second voltage detection component 213 can also be installed at the negative terminal of the DC bus 130 and detect the voltage at the negative terminal of the DC bus 130 as an electrical parameter. The second voltage detection component 213 can also be installed at any two of the positive, negative, and midpoint locations of the DC bus 130 and detect two voltage values ​​from the positive, negative, and midpoint locations as electrical parameters. Alternatively, the second voltage detection component 213 can be installed at the positive, negative, and midpoint locations of the DC bus 130 and detect the voltage at the midpoint, the positive terminal, and the negative terminal of the DC bus 130 as electrical parameters.

[0114] During the testing of inverter 100, a preset external interference signal can be provided to inverter 100 to generate a corresponding preset test surge current in the surge circuit inside inverter 100. The position of the second voltage detection component 213 and the detected value are recorded to determine the correspondence between the voltage of the positive terminal, the voltage of the midpoint and the voltage of the negative terminal of DC bus 130 and the preset test surge current.

[0115] The correspondence between the voltage at the positive terminal, the voltage at the midpoint, and the voltage at the negative terminal of the DC bus 130 and the preset test surge current can be preset in the control program inside the controller 220. This allows the controller 220 to determine the surge current based on the position of the second voltage detection component 213 and the detected voltage. Before the surge current rises to the first preset voltage value, the controller 220 can determine that the electrical parameters meet the lightning surge conditions based on the surge current and control the switching devices in the inverter circuit 140 to turn off.

[0116] Thus, the controller 220 can determine the shutdown of each switching device in the inverter circuit 140 based on the voltage information of the DC bus 130.

[0117] Referring to Figure 9, the second voltage detection component 213 is connected in parallel between the positive and negative terminals of the DC bus 130. The second voltage detection component 213 is used to detect the voltage difference between the positive and negative terminals of the DC bus 130 as an electrical parameter. And / or the second voltage detection component 213 is connected in parallel between the positive terminal and the midpoint of the DC bus 130. The second voltage detection component 213 is used to detect the voltage difference between the positive terminal and the midpoint of the DC bus 130 as an electrical parameter. And / or the second voltage detection component 213 is connected in parallel between the negative terminal and the midpoint of the DC bus 130. The second voltage detection component 213 is used to detect the voltage difference between the negative terminal and the midpoint of the DC bus 130 as an electrical parameter. The controller 220 is configured to control the switching devices in the inverter circuit 140 to turn off when at least one of the following parameters satisfies the lightning surge condition: the voltage difference between the positive and negative terminals of the DC bus 130, the voltage difference between the positive terminal and the midpoint of the DC bus 130, and the voltage difference between the negative terminal and the midpoint of the DC bus 130.

[0118] In this embodiment, when an external interference signal (such as a lightning surge) affects the inverter 100, the surge current can flow through the positive terminal and the midpoint of the DC bus 130, thereby affecting the voltage difference between the positive terminal and the midpoint of the DC bus 130. The second voltage detection component 213 can be connected in parallel between the positive terminal and the midpoint of the DC bus 130 and detect the voltage difference between the positive terminal and the midpoint of the DC bus 130 as an electrical parameter. The surge current can also flow through the negative terminal and the midpoint of the DC bus 130, thereby affecting the voltage difference between the negative terminal and the midpoint of the DC bus 130. The second voltage detection component 213 can be connected in parallel between the negative terminal and the midpoint of the DC bus 130 and detect the voltage difference between the negative terminal and the midpoint of the DC bus 130 as an electrical parameter. Surge current can also flow through the positive and negative terminals of DC bus 130, thereby affecting the voltage difference between the positive and negative terminals of DC bus 130. The second voltage detection component 213 can be connected in parallel between the positive and negative terminals of DC bus 130 and detect the voltage difference between the positive and negative terminals of DC bus 130 as an electrical parameter.

[0119] The second voltage detection component 213 can also be connected in parallel between the positive and negative terminals of the DC bus 130 and between the positive terminal and the midpoint of the DC bus 130, and detect the voltage difference between the positive and negative terminals of the DC bus 130 and the voltage difference between the positive terminal and the midpoint as electrical parameters. The second voltage detection component 213 can also be connected in parallel between the positive and negative terminals of the DC bus 130 and between the negative terminal and the midpoint of the DC bus 130, and detect the voltage difference between the positive and negative terminals of the DC bus 130 and the voltage difference between the negative terminal and the midpoint as electrical parameters. The second voltage detection component 213 can also be connected in parallel between the midpoint and the negative terminal of the DC bus 130 and between the positive terminal and the midpoint of the DC bus 130, and detect the voltage difference between the midpoint and the negative terminal of the DC bus 130 and the voltage difference between the positive terminal and the midpoint as electrical parameters.

[0120] The second voltage detection component 213 can also be connected in parallel between the positive and negative terminals of the DC bus 130, between the positive terminal and the midpoint of the DC bus 130, and between the negative terminal and the midpoint of the DC bus 130, and detect the voltage difference between the positive and negative terminals of the DC bus 130, the voltage difference between the positive terminal and the midpoint, and the voltage difference between the negative terminal and the midpoint as electrical parameters.

[0121] The correspondence between the surge current and the voltage difference between the positive and negative terminals of the DC bus 130 can be pre-set in the control program within the controller 220, allowing the controller 220 to determine the surge current based on the voltage detected by the second voltage detection component 213 connected in parallel between the positive and negative terminals of the DC bus 130. The correspondence between the surge current and the voltage difference between the positive terminal and the midpoint of the DC bus 130 can be pre-set in the control program within the controller 220, allowing the controller 220 to determine the surge current based on the voltage detected by the second voltage detection component 213 connected in parallel between the positive terminal and the midpoint of the DC bus 130. The correspondence between the surge current and the voltage difference between the midpoint and the negative terminal of the DC bus 130 can be pre-set in the control program within the controller 220, allowing the controller 220 to determine the surge current based on the voltage detected by the second voltage detection component 213 connected in parallel between the midpoint and the negative terminal of the DC bus 130.

[0122] Thus, the controller 220 can determine the shutdown of each switching device in the inverter circuit 140 based on the voltage difference between the positive and negative terminals of the DC bus 130, the voltage difference between the positive terminal and the midpoint, or the voltage difference between the midpoint and the negative terminal.

[0123] Referring to Figure 7, the waveform of the negative half bus corresponds to the waveform of the electrical parameters detected by the second voltage detection component 213 changing over time. Based on the negative half bus waveform, it can be determined that during the test of the inverter 100, the second voltage detection component 213 responds quickly, indicating that the electrical parameters detected by the second voltage detection component 213 meet the lightning surge conditions earlier. Therefore, the controller 220 can control the switching devices in the inverter circuit 140 to turn off in advance.

[0124] Referring to FIG10, in some embodiments, the detection device 210 includes a second current detection component 214. The second current detection component 214 is configured to be disposed on the connection line between the DC bus 130 and the inverter circuit 140, for detecting current information of the connection line between the DC bus 130 and the inverter circuit 140 as an electrical parameter. The controller 220 is configured to control the switching devices in the inverter circuit 140 to turn off when at least one parameter in the current information of the connection line between the DC bus 130 and the inverter circuit 140 satisfies the lightning surge condition.

[0125] In this embodiment, the surge current path within the inverter 100 may include the connection line between the DC bus 130 and the inverter circuit 140. When external interference signals (such as lightning surges) affect the inverter 100, the surge current may flow through the DC bus 130 and the inverter circuit 140, thereby affecting the current flowing through the connection line between the DC bus 130 and the inverter circuit 140.

[0126] The second current detection component 214 can be installed in the connection line between the DC bus 130 and the inverter circuit 140, and detect the current flowing through the connection line between the DC bus 130 and the inverter circuit 140.

[0127] During the testing of inverter 100, a preset external interference signal can be provided to inverter 100 to generate a corresponding preset test surge current in the surge circuit inside inverter 100. The position of the second current detection component 214 and the detected value are recorded to determine the correspondence between the current flowing through the connection line between DC bus 130 and inverter circuit 140 and the preset test surge current.

[0128] The correspondence between the current flowing through the connection line between the DC bus 130 and the inverter circuit 140 and the preset test surge current can be preset in the control program inside the controller 220. This allows the controller 220 to determine the surge current based on the position of the second current detection component 214 and the detected current. Before the surge current rises to the first preset voltage value, the controller 220 can determine that the electrical parameters meet the lightning surge conditions based on the surge current and control the switching devices in the inverter circuit 140 to turn off.

[0129] Thus, the controller 220 can control the switching devices of the inverter circuit 140 to turn off based on the current flowing through the connection line between the DC bus 130 and the inverter circuit 140.

[0130] Referring to Figures 10 and 11, in some embodiments, the positive terminal of the DC bus 130 is connected to the DC terminal of the inverter circuit 140 at a first node, the midpoint of the DC bus 130 is connected to the DC terminal of the inverter circuit 140 at a second node, and the negative terminal of the DC bus 130 is connected to the DC terminal of the inverter circuit 140 at a third node. A second current detection component 214 is configured as a connection line between the positive terminal of the DC bus 130 and the first node, for detecting the current flowing through the positive terminal of the DC bus 130 and the first node; and / or the second current detection component 214 is configured as a connection line between the midpoint of the DC bus 130 and the second node, for detecting the current flowing through the midpoint of the DC bus 130 and the second node; and / or the second current detection component 214 is configured as a connection line between the negative terminal of the DC bus 130 and the third node, for detecting the current flowing through the negative terminal of the DC bus 130 and the third node. The controller 220 is configured to control the switching devices in the inverter circuit 140 to turn off when at least one of the following parameters satisfies the lightning surge condition: the current flowing between the positive terminal and the first node of the DC bus 130, the current flowing between the midpoint and the second node of the DC bus 130, and the current flowing between the negative terminal and the third node of the DC bus 130.

[0131] In this embodiment, the inverter circuit 140 may include a first node, a second node, and a third node. The first node may be designated as node N1, the second node as node N2, and the third node as node N3. The positive terminal of the DC bus 130 and the inverter circuit 140 may be connected to node N1, the midpoint of the DC bus 130 and the inverter circuit 140 may be connected to node N2, and the negative terminal of the DC bus 130 and the inverter circuit 140 may be connected to node N3.

[0132] The second current detection component 214 can be disposed between the positive terminal of the DC bus 130 and node N1, and detect the current flowing through the positive terminal of the DC bus 130 and node N1 as an electrical parameter. The second current detection component 214 can be disposed between the midpoint of the DC bus 130 and node N2, and detect the current flowing through the midpoint of the DC bus 130 and node N2 as an electrical parameter. The second current detection component 214 can be disposed between the negative terminal of the DC bus 130 and node N3, and detect the current flowing through the negative terminal of the DC bus 130 and node N3 as an electrical parameter.

[0133] The second current detection component 214 can also be disposed between the positive terminal and node N1 and the midpoint and node N2 of the DC bus 130, and detect the current flowing through the positive terminal and node N1 and the current flowing through the midpoint and node N2 of the DC bus 130 as electrical parameters. The second current detection component 214 can also be disposed between the positive terminal and node N1 and the negative terminal and node N3 of the DC bus 130, and detect the current flowing through the positive terminal and node N1 and the current flowing through the negative terminal and node N3 of the DC bus 130 as electrical parameters. The second current detection component 214 can also be disposed between the negative terminal and node N3 and the midpoint and node N2 of the DC bus 130, and detect the current flowing through the negative terminal and node N3 and the current flowing through the midpoint and node N2 of the DC bus 130 as electrical parameters.

[0134] The second current detection component 214 can also be set between the positive terminal and node N1, the midpoint and node N2 of the DC bus 130, and the negative terminal and node N3 of the DC bus 130, and detect the current flowing through the positive terminal and node N1, the midpoint and node N2 of the DC bus 130, and the negative terminal and node N3 of the DC bus 130 as electrical parameters.

[0135] When external interference signals (such as lightning surges) affect the inverter 100, the surge current can flow through the positive terminal of the DC bus 130 and node N1, thus affecting the current flowing through the positive terminal of the DC bus 130 and node N1. The surge current can also flow through the midpoint of the DC bus 130 and node N2, thus affecting the current flowing through the midpoint of the DC bus 130 and node N2. The surge current can also flow through the negative terminal of the DC bus 130 and node N3, thus affecting the current flowing through the negative terminal of the DC bus 130 and node N3.

[0136] During the testing of inverter 100, a preset external interference signal can be provided to inverter 100 to generate a corresponding preset test surge current in the surge circuit inside inverter 100. The position of the second current detection component 214 and the detected value are recorded to determine the correspondence between the current flowing through the positive terminal and node N1 of DC bus 130, the current flowing through the midpoint and node N2 of DC bus 130, and the current flowing through the negative terminal and node N3 of DC bus 130 and the preset test surge current.

[0137] The correspondence between the current flowing through the positive terminal and node N1 of DC bus 130, the current flowing through the midpoint and node N2 of DC bus 130, and the current flowing through the negative terminal and node N3 of DC bus 130, and the preset test surge current can be preset in the control program inside the controller 220. This allows the controller 220 to determine the surge current based on the position of the second current detection component 214 and the detected current. Before the surge current rises to the first preset voltage value, the controller 220 can determine that the electrical parameters meet the lightning surge conditions based on the surge current and control the switching devices in the inverter circuit 140 to turn off.

[0138] Referring to FIG10, in some embodiments, the inverter circuit 140 may include transistors T1, T2, T3 and T4, diodes D1 and D2.

[0139] In some embodiments, the inverter circuit 140 may have multiple corresponding transistors T1, T2, T3, T4, diodes D1 and D2. Taking FIG10 as an example, the inverter current 140 includes three corresponding transistors T1, T2, T3, T4, diodes D1 and D2.

[0140] Transistors T1, T2, T3, and T4 can be connected in series between the positive and negative terminals of DC bus 130. The positive terminal of DC bus 130 can be connected to the first terminal of transistor T1 at node N1. The second terminal of transistor T1 can be connected to the cathode of diode D2. The anode of diode D2 can be connected to the cathode of diode D1 and the midpoint of DC bus 130 at node N2. The anode of diode D1 can be connected to the first terminal of transistor T4. The second terminal of transistor T4 can be connected to the negative terminal of DC bus 130 at node N3. AC port 120 can be connected between transistors T2 and T3.

[0141] When the controller 220 controls the switching devices in the inverter circuit 140 to turn off, the controller 220 can control transistors T1 and T4 to turn off. After determining that transistors T1 and T4 are turned off, the controller 220 then controls transistors T2 and T3 to turn off.

[0142] Referring to FIG11, in some embodiments, inverter circuit 140 may include transistor T1, transistor T2, transistor T3 and transistor T4.

[0143] In some embodiments, the inverter circuit 140 may include a plurality of corresponding transistors T1, T2, T3 and T4. Taking FIG11 as an example, the inverter current 140 includes three corresponding transistors T1, T2, T3 and T4.

[0144] Transistors T1 and T4 can be connected in series between the positive and negative terminals of DC bus 130. The midpoint of DC bus 130 can be connected between transistors T1 and T4 via transistors T3 and T2. The internal junction diodes of transistor T3 and T2 are mutually cut off. The first terminal of transistor T1 is connected to the positive terminal of DC bus 130 at node N1, the second terminal of transistor T1 is connected to the first terminal of transistor T4, and the second terminal of transistor T4 is connected to the negative terminal of DC bus 130 at node N3. The first terminal of transistor T3 is connected to the midpoint of DC bus 130 at node N2, the second terminal of transistor T3 is connected to the first terminal of transistor T2, and the second terminal of transistor T2 is connected to the second terminal of transistor T1.

[0145] When the controller 220 controls the switching devices in the inverter circuit 140 to turn off, the controller 220 can first control transistors T1 and T4 to turn off, and after determining that transistors T1 and T4 are turned off, then control transistors T2 and T3 to turn off.

[0146] Referring to Figure 12, in some embodiments, the DC surge protection device 230 is connected between the DC port 110 and the ground electrode, and is configured to connect the DC port 110 and the ground electrode during startup. The detection device 210 includes a third current detection component 215, which is configured to be disposed between the DC surge protection device 230 and the ground electrode connection line for detecting the current flowing through the DC surge protection device 230 and the ground electrode. The controller 220 is configured to control the switching devices in the inverter circuit 140 to turn off when the current flowing through the DC surge protection device 230 and the ground electrode meets the lightning surge condition.

[0147] In this embodiment, the DC surge protection device 230 is configured to connect between the DC port 110 and the ground, and to connect the DC port 110 and the ground when all switching devices in the control inverter circuit 140 are turned off. When a surge current or voltage suddenly occurs in an electrical circuit or communication line, the DC surge protection device 230 can conduct and shunt the current in a very short time, thereby preventing the surge from damaging other equipment in the circuit.

[0148] The surge current path within the inverter 100 can include the path between the DC surge protection device 230 and the ground. When external interference signals (such as lightning surges) affect the inverter 100, the surge current can flow through the DC surge protection device 230 and the ground.

[0149] During the testing of inverter 100, a preset external interference signal can be provided to inverter 100 to generate a corresponding preset test surge current in the surge circuit inside inverter 100, and the current detected by the third current detection component 215 is recorded to determine the correspondence between the current flowing through DC surge protection device 230 and the preset test surge current.

[0150] The correspondence between the current flowing through the DC surge protection device 230 and the preset test surge current can be preset in the control program inside the controller 220, so that the controller 220 can determine the surge current based on the current detected by the third current detection component 215. Before the surge current rises to the first preset voltage value, the controller 220 can determine that the electrical parameters meet the lightning surge conditions based on the surge current, and control the switching devices in the inverter circuit 140 to turn off.

[0151] Thus, the controller 220 can control the switching devices of the inverter circuit 140 to turn off according to the current flowing through the DC surge protection device 230.

[0152] Referring to Figure 13, in some embodiments, the AC surge protection device 240 is connected between the AC port 120 and the ground electrode and is configured to connect the AC port 120 and the ground electrode during startup. The detection device 210 includes a fourth current detection component 216, which is configured to be disposed between the AC surge protection device 240 and the ground electrode connection line for detecting the current flowing through the AC surge protection device 240 and the ground electrode. The controller 220 is configured to control the switching devices in the inverter circuit 140 to turn off when the current flowing through the AC surge protection device 240 and the ground electrode meets the lightning surge condition.

[0153] In this embodiment, the AC surge protection device 240 is configured to connect the AC port 120 to the ground, and connects the AC port 120 to the ground when the switching devices in the control inverter circuit 140 are turned off. When a surge current or voltage suddenly occurs in the electrical circuit or communication line, the AC surge protection device 240 can conduct and shunt the current in a very short time, thereby preventing the surge from damaging other equipment in the circuit.

[0154] The surge current path within the inverter 100 can include the path between the AC surge protection device 240 and the ground. When external interference signals (such as lightning surges) affect the inverter 100, the surge current can flow through the AC surge protection device 240 and the ground.

[0155] During the testing of inverter 100, a preset external interference signal can be provided to inverter 100, causing the surge circuit inside inverter 100 to generate a corresponding preset test surge current, and the current detected by the fourth current detection component 216 is recorded to determine the correspondence between the current flowing through AC surge protection device 240 and the preset test surge current.

[0156] The correspondence between the current flowing through the AC surge protection device 240 and the preset test surge current can be preset in the control program inside the controller 220, so that the controller 220 can determine the surge current based on the current detected by the fourth current detection component 216. Before the surge current rises to the first preset voltage value, the controller 220 can determine that the electrical parameters meet the lightning surge conditions based on the surge current, and control the switching devices in the inverter circuit 140 to turn off.

[0157] Thus, the controller 220 can control the switching devices of the inverter circuit 140 to turn off according to the current flowing through the AC surge protection device 240.

[0158] Referring to FIG14, in some embodiments, the inverter 100 includes an AC filter capacitor 160, the first end of which is connected to the AC port 120, and the second end of which is connected to the midpoint of the DC bus 130.

[0159] Referring to Figure 15, the detection device 210 includes a fifth current detection component 217, which is configured to be connected in series with the AC filter capacitor 160 for detecting the current flowing through the AC filter capacitor 160. The controller 220 is configured to control the switching devices in the inverter circuit 140 to turn off when the current flowing through the AC filter capacitor 160 meets the lightning surge condition.

[0160] In this embodiment, the surge current path within the inverter 100 may include a connection line flowing through the midpoint between the AC filter capacitor 160 and the DC bus 130. When external interference signals (such as lightning surges) affect the inverter 100, the surge current may flow through the midpoint between the AC filter capacitor 160 and the DC bus 130, thereby affecting the current flowing through the AC filter capacitor 160.

[0161] The fifth current detection component 217 can be connected in series with the AC filter capacitor 160 and used to detect the current flowing through the AC filter capacitor 160 as an electrical parameter.

[0162] During the testing of inverter 100, a preset external interference signal can be provided to inverter 100 to generate a corresponding preset test surge current in the surge circuit inside inverter 100, so as to determine the correspondence between the current flowing through AC filter capacitor 160 and the preset test surge current.

[0163] The correspondence between the current flowing through the AC filter capacitor 160 and the preset test surge current can be preset in the control program inside the controller 220, so that the controller 220 can determine the surge current based on the current detected by the fifth current detection component 217. Before the surge current rises to the first preset voltage value, the controller 220 can determine that the electrical parameters meet the lightning surge conditions based on the surge current, and control the switching devices in the inverter circuit 140 to turn off.

[0164] Referring to Figure 16, in some embodiments, the AC port 120 includes multiple AC connection terminals 121, and the inverter 100 includes multiple AC filter capacitors 160. The first end of each AC filter capacitor 160 is connected to the corresponding AC connection terminal 121, and the second end of each AC filter capacitor 160 is connected to a fourth node. The fourth node is connected to the midpoint of the DC bus 130. The fifth current detection assembly 217 includes multiple third current detection elements 2171 and / or fourth current detection elements 2172. Each third current detection element 2171 is configured to be connected in series with any one of the AC filter capacitors 160 to detect the current flowing through any one of the AC filter capacitors 160 as an electrical parameter. The fourth current detection element 2172 is disposed between the fourth node and the midpoint of the DC bus 130 to detect the total current flowing through the multiple AC filter capacitors 160 as an electrical parameter. The controller 220 is configured to control the switching devices in the inverter circuit 140 to turn off when at least one parameter of the current flowing through any one AC filter capacitor 160 and the total current flowing through multiple AC filter capacitors 160 satisfies the lightning surge condition.

[0165] In this embodiment, taking Figure 16 as an example, the multiple AC connection terminals 121 of the AC port 120 can be respectively configured as phase A connection terminals, phase B connection terminals, and phase C connection terminals. The multiple AC filter capacitors 160 can be respectively configured as capacitor elements C1, C2, and C3. The phase A connection terminal can be connected to the midpoint of the DC bus through capacitor element C1. The phase B connection terminal can be connected to the midpoint of the DC bus through capacitor element C2. The phase C connection terminal can be connected to the midpoint of the DC bus through capacitor element C3.

[0166] The third current sensing element 2171 may include any one of elements CT1, CT2, and CT3. Element CT1 may be connected in series between capacitor element C1 and the midpoint of the DC bus, and detects the current flowing through capacitor element C1. Element CT2 may be connected in series between capacitor element C2 and the midpoint of the DC bus, and detects the current flowing through capacitor element C2. Element CT3 may be connected in series between capacitor element C3 and the midpoint of the DC bus, and detects the current flowing through capacitor element C3. The surge current path within the inverter 100 may include the path between any one or more of capacitor elements C1, C2, and C3 and the midpoint of the DC bus 130.

[0167] The fourth current sensing element 2172 may include element CT4. Element CT1, element CT2 and element CT3 can be connected to the midpoint of the DC bus through element CT4. Element CT4 can detect the total current flowing through capacitor elements C1, C2 and C3.

[0168] If a third current sensing element 2171 malfunctions, the corresponding electrical parameters can be calculated and determined using other third current sensing elements 2171 and the fourth current sensing element 2172, thus improving the accuracy of the detection parameters of the fifth current sensing component 217. For example, if element CT1 malfunctions, the detection value of element CT1 can be determined based on the detection values ​​of elements CT2, CT3, and CT4, thereby determining the loop current flowing through capacitor element C1.

[0169] During the testing of inverter 100, a preset external interference signal can be provided to inverter 100, so that the surge circuit inside inverter 100 generates a corresponding preset test surge current, so as to determine the correspondence between the current flowing through capacitor elements C1, C2 and C3 and the preset test surge current.

[0170] The correspondence between the current flowing through capacitors C1, C2, and C3 and the preset test surge current can be preset in the control program inside the controller 220. This allows the controller 220 to determine the surge current based on the position of the third current detection element 2171 and the detected current, or based on the current detected by the fourth current detection element 2172. Before the surge current rises to the first preset current value, the controller 220 can determine that the electrical parameters meet the lightning surge conditions based on the surge current and control the switching devices in the inverter circuit 140 to turn off.

[0171] Thus, if a third current sensing element 2171 fails to function properly, the corresponding electrical parameters can be calculated and determined using other third current sensing elements 2171 and the fourth current sensing element 2172, thereby improving the accuracy of the electrical parameters detected by the fifth current sensing component 215.

[0172] Referring to Figure 7, the CT4 waveform corresponds to the waveform diagram of the electrical parameters detected by the fourth current sensing element 2172 changing over time. Based on the CT4 waveform, it can be determined that during the testing of the inverter 100, compared to the other sensing elements in this disclosure, the fourth current sensing element 2172 has the fastest response speed. This means that the electrical parameters detected by the fourth current sensing element 2172 meet the lightning surge conditions earliest, ensuring that the controller 220 can control the switching devices in the inverter circuit 140 to turn off in advance.

[0173] Referring to Figure 17, in some embodiments, the inverter 100 includes a transformer circuit 150, with a DC port 110 connected to the input terminal of the transformer circuit 150, and the output terminal of the transformer circuit 150 connected to the DC bus 130. The detection device 210 includes a sixth current detection component 218, configured to be located at the input and / or output terminals of the transformer circuit 150, for detecting current information at the input and / or output terminals of the transformer circuit 150 as electrical parameters. The controller 220 is configured to control the switching devices in the inverter circuit 140 to turn off when at least one parameter in the current information at the input or output terminal of the transformer circuit 150 satisfies a lightning surge condition.

[0174] In this embodiment, the surge current path within the inverter 100 may include the connection line between the transformer circuit 150 and the DC port 110, or the connection line between the transformer circuit 150 and the DC bus 130. When external interference signals (such as lightning surges) affect the inverter 100, the surge current may flow through the DC port 110 and the input terminal of the transformer circuit 150, or it may flow through the output terminal of the transformer circuit 150 and the DC bus 130, thereby affecting the current information at the input or output terminal of the transformer circuit 150.

[0175] The sixth current detection component 218 can be installed at the input terminal of the transformer circuit 150 and detects the current flowing through the input terminal of the transformer circuit 150 as an electrical parameter. The sixth current detection component 218 can also be installed at the output terminal of the transformer circuit 150 and detects the current flowing through the output terminal of the transformer circuit 150 as an electrical parameter. Furthermore, the sixth current detection component 218 can be installed at both the input and output terminals of the transformer circuit 150 and detects both the current flowing through the input terminal and the current flowing through the output terminal of the transformer circuit 150 as electrical parameters.

[0176] During the testing of inverter 100, a preset external interference signal can be provided to inverter 100 to generate a corresponding preset test surge current in the surge circuit inside inverter 100. The position of the sixth current detection component 218 and the detected value are recorded to determine the correspondence between the current information at the input and output terminals of transformer circuit 150 and the preset test surge current.

[0177] The correspondence between the current information at the input and output terminals of the transformer circuit 150 and the preset test surge current can be pre-set in the control program inside the controller 220, so that the controller 220 can determine the surge current based on the position of the sixth current detection component 218 and the detected current. Before the surge current rises to the first preset voltage value, the controller 220 can determine that the electrical parameters meet the lightning surge conditions based on the surge current and control the switching devices in the inverter circuit 140 to turn off.

[0178] Thus, the controller 220 can control the switching devices of the inverter circuit 140 to turn off based on the current information at the input or output of the transformer circuit 150.

[0179] Referring to Figure 18, in some embodiments, the sixth current detection component 218 is configured to be connected in series with the input terminal of the transformer circuit 150 to detect the current flowing through the input terminal of the transformer circuit 150 as an electrical parameter, and / or the sixth current detection component 218 is configured to be connected in series with the output terminal of the transformer circuit 150 to detect the current flowing through the output terminal of the transformer circuit 150 as an electrical parameter. The controller 220 is configured to control the switching devices in the inverter circuit 140 to turn off when at least one of the parameters, the current flowing through the input terminal of the transformer circuit 150 and the current flowing through the output terminal of the transformer circuit 150, satisfies the lightning surge condition.

[0180] In this embodiment, the surge current path within the inverter 100 may include the connection line between the transformer circuit 150 and the DC port 110, or the connection line between the transformer circuit 150 and the DC bus 130. When external interference signals (such as lightning surges) affect the inverter 100, the surge current may flow through the DC port 110 and the input terminal of the transformer circuit 150, or it may flow through the output terminal of the transformer circuit 150 and the DC bus 130, thereby affecting the current flowing through the input terminal of the transformer circuit 150 and the current flowing through the output terminal of the transformer circuit 150.

[0181] The transformer circuit 150 may include a capacitor Ca, a resistor Ra, a transistor Ta, and a diode Da. The first terminal of capacitor Ca can be connected to the PV+ terminal, and the second terminal of capacitor Ca can be connected to the PV- terminal. The first terminal of capacitor Ca can be connected to the anode of diode Da through resistor Ra, and the cathode of diode Da can be connected to the positive terminal of DC bus 130. The PV- terminal can be connected to the negative terminal of DC bus 130, and transistor Ta can be connected between the positive and negative terminals of DC bus 130.

[0182] The sixth current detection component 218 can be connected in series between the cathode of diode Da and the positive terminal of DC bus 130. The sixth current detection component 218 can also be connected in series between PV+ terminal and resistor element Ra, and detect the current flowing through the input terminal of transformer circuit 150.

[0183] The sixth current detection component 218 can also be connected in series between the PV- terminal and the negative terminal of the DC bus 130, and detect the current flowing through the output terminal of the transformer circuit 150.

[0184] During the testing of inverter 100, a preset external interference signal can be provided to inverter 100 to generate a corresponding preset test surge current in the surge circuit inside inverter 100. The position of the sixth current detection component 218 and the detected value are recorded to determine the correspondence between the current flowing through the input and output terminals of transformer circuit 150 and the preset test surge current.

[0185] The correspondence between the current flowing through the input and output terminals of the transformer circuit 150 and the preset test surge current can be preset in the control program inside the controller 220, so that the controller 220 can determine the surge current based on the position of the sixth current detection component 218 and the detected current. Before the surge current rises to the first preset voltage value, the controller 220 can determine that the electrical parameters meet the lightning surge conditions based on the surge current and control the switching devices in the inverter circuit 140 to turn off.

[0186] Thus, the controller 220 can control the switching devices of the inverter circuit 140 to turn off according to the current flowing through the input or output terminal of the transformer circuit 150.

[0187] Referring to FIG19, this disclosure also provides a photovoltaic energy storage system 1000, which may include a surge protection device 200 and an inverter 100 provided in this disclosure.

[0188] In some embodiments, the photovoltaic energy storage system 1000 may include a photovoltaic module 300, which may be connected to a DC port 110, and the DC port 110 may be connected to a DC voltage provided by the photovoltaic module 300.

[0189] In this embodiment, the photovoltaic energy storage system 1000 can be installed outdoors and distributed on mountains or rooftops. The photovoltaic module 300 can be configured as a solar panel, and the photovoltaic energy storage system 1000 can be built relatively high. The frame of the solar panel can be configured as a conductor so that the solar panel can face the sun and be installed without shading, so that the solar panel can convert solar energy into electrical energy and provide DC voltage to the DC port 110.

[0190] When thunderstorms occur, solar panels or lightning arresters may be damaged by lightning surges. Inverter 100 will sense large surge currents and voltages, which may cause inverter 100 to fail due to overvoltage or overcurrent.

[0191] In the photovoltaic energy storage system 1000 of this disclosure embodiment, the controller 220 can control each switching device in the inverter circuit 140 to turn off before the surge current value rises to a first preset current value, so that each switching device is in the off state before overcurrent or overvoltage, avoiding overvoltage or overcurrent failure of the switching device caused by high voltage and high current.

[0192] In this document, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes that element. Furthermore, the scope of the methods and apparatuses in the embodiments of this disclosure is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0193] Through the description of the above embodiments, those skilled in the art can clearly understand that the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better embodiment. Based on this understanding, the technical solutions of this disclosure can essentially be embodied in the form of a computer software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of this disclosure.

[0194] The embodiments of this disclosure have been described above with reference to the accompanying drawings. However, this disclosure is not limited to the specific embodiments described above. The embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this disclosure without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this disclosure.

[0195] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0196] Although embodiments of this disclosure have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this disclosure, the scope of which is defined by the claims and their equivalents.

Claims

1. An inverter, wherein, The inverter includes a DC surge protection device, a DC bus, an inverter circuit, a detection device, an AC surge protection device, a detection device, and a controller; The DC terminal of the inverter circuit is connected to the DC port of the inverter via the DC bus, and the AC terminal of the inverter circuit is connected to the AC port of the inverter. The detection device is configured to be installed in the surge circuit of the inverter and is configured to detect the electrical parameters of the surge circuit, which is the flow path of the surge current in the inverter. The controller is configured to control each switching device in the inverter circuit to turn off when the electrical parameters detected by the detection device meet the lightning surge conditions, and to activate the DC surge protection device and the AC surge protection device after each switching device is turned off.

2. The inverter of claim 1, wherein, The detection device includes a first current detection component; The first current detection component is configured to be located at the positive and / or negative terminal of the DC port, and is configured to detect the current information of the positive or negative terminal of the DC port as the electrical parameter; The controller is configured to control the switching devices in the inverter circuit to turn off when at least one parameter of the current information of the positive and negative terminals of the DC port satisfies the lightning surge condition.

3. The inverter of claim 2, wherein, The DC port includes a positive terminal and a negative terminal. The positive terminal is configured to be connected to the positive terminal of a DC source, and the negative terminal is configured to be connected to the negative terminal of a DC source. The positive terminal of the DC port is connected to the positive terminal of the connection, and the negative terminal of the DC port is connected to the negative terminal of the connection. The first current detection component is configured to be connected in series with the positive terminal of the connection terminal, and is configured to detect the current flowing through the positive terminal of the connection terminal as the electrical parameter, and / or The first current detection component is configured to be connected in series with the negative terminal of the connection terminal, and is configured to detect the current flowing through the negative terminal of the connection terminal as the electrical parameter; The controller is configured to turn off each switching device in the inverter circuit when at least one parameter of the current flowing through the positive terminal of the connection and the current flowing through the negative terminal of the connection satisfies the lightning surge condition.

4. The inverter of claim 2 or 3, wherein, The DC port includes multiple positive terminals and multiple negative terminals. Each positive terminal is configured to be connected to a corresponding positive DC source, and each negative terminal is configured to be connected to a corresponding negative DC source. The positive terminal of the DC port is connected to multiple positive terminals and connected to multiple positive DC sources through the multiple positive terminals. The negative terminal of the DC port is connected to multiple negative terminals and connected to multiple negative DC sources through the multiple negative terminals. The first current detection component includes a plurality of first current detection elements and second current detection elements. Each first current detection element is configured to be connected in series with any one of the positive terminals and / or any one of the negative terminals, and is configured to detect the current flowing through any one of the positive terminals and / or any one of the negative terminals as the electrical parameter. The second current sensing element is configured to be located at the positive and / or negative terminal of the DC port, and is configured to detect the total current flowing through the positive terminals of the plurality of connection terminals and / or the total current flowing through the negative terminals of the plurality of connection terminals, as the electrical parameter; The controller is configured to control each switching device in the inverter circuit to turn off when at least one of the following parameters—the current flowing through any one of the positive terminals, the current flowing through any one of the negative terminals, the total current flowing through multiple positive terminals, and the total current flowing through multiple negative terminals—satisfies the lightning surge condition.

5. The inverter according to any one of claims 1 to 4, wherein The detection device includes a first voltage detection component; The first voltage detection component is configured to be located at the positive and / or negative terminal of the DC port, and is configured to detect the voltage information of the positive and / or negative terminal of the DC port as the electrical parameter; The controller is configured to control the switching devices in the inverter circuit to turn off when at least one parameter of the voltage information of the positive and negative terminals of the DC port meets the lightning surge condition.

6. The inverter of claim 5, wherein, The first voltage detection component is connected in parallel between the positive and negative terminals of the DC port. The first voltage detection component is configured to detect the voltage difference between the positive and negative terminals of the DC port as the electrical parameter. The controller is configured to turn off each switching device in the inverter circuit when the voltage difference between the positive and negative terminals of the DC port meets the lightning surge condition.

7. The inverter according to any one of claims 1 to 6, wherein The detection device includes a second voltage detection component; The second voltage detection component is configured to be located at at least one of the positive, negative, or midpoint of the DC bus, and is configured to detect voltage information of at least one of the positive, negative, or midpoint of the DC bus as the electrical parameter; The controller is configured to control the switching devices in the inverter circuit to turn off when the voltage information of at least one of the positive, negative, or midpoint of the DC bus meets the lightning surge condition.

8. The inverter of claim 7, wherein, The second voltage detection component is connected in parallel between the positive and negative terminals of the DC bus. The second voltage detection component is configured to detect the voltage difference between the positive and negative terminals of the DC bus as an electrical parameter, and / or The second voltage detection component is connected in parallel between the positive terminal and the midpoint of the DC bus. The second voltage detection component is configured to detect the voltage difference between the positive terminal and the midpoint of the DC bus as an electrical parameter, and / or The second voltage detection component is connected in parallel between the negative terminal and the midpoint of the DC bus. The second voltage detection component is configured to detect the voltage difference between the negative terminal and the midpoint of the DC bus as the electrical parameter. The controller is configured to control each switching device in the inverter circuit to turn off when at least one of the following parameters—the voltage difference between the positive and negative terminals of the DC bus, the voltage difference between the positive terminal and the midpoint of the DC bus, and the voltage difference between the negative terminal and the midpoint of the DC bus—satisfies the lightning surge condition.

9. The inverter according to any one of claims 1 to 8, wherein The detection device includes a second current detection component; The second current detection component is configured to be disposed in the connection line between the DC bus and the inverter circuit, and is configured to detect the current information of the connection line between the DC bus and the inverter circuit as the electrical parameter; The controller is configured to control each switching device in the inverter circuit to turn off when at least one parameter in the current information of the connection line between the DC bus and the inverter circuit meets the lightning surge condition.

10. The inverter of claim 9, wherein, The positive terminal of the DC bus is connected to the DC terminal of the inverter circuit at a first node, the midpoint of the DC bus is connected to the DC terminal of the inverter circuit at a second node, and the negative terminal of the DC bus is connected to the DC terminal of the inverter circuit at a third node. The second current detection component is configured as a connection line between the positive terminal of the DC bus and the first node, and is configured to detect the current flowing through the positive terminal of the DC bus and the first node; and / or The second current detection component is configured to be disposed in a connection line between the midpoint of the DC bus and the second node, and is configured to detect the current flowing through the midpoint of the DC bus and the second node; and / or The second current detection component is configured as a connection line between the negative terminal of the DC bus and the third node, and is configured to detect the current flowing through the negative terminal of the DC bus and the third node; The controller is configured to control the switching devices in the inverter circuit to turn off when at least one of the following parameters—the current flowing between the positive terminal of the DC bus and the first node, the current flowing between the midpoint of the DC bus and the second node, and the current flowing between the negative terminal of the DC bus and the third node—satisfies the lightning surge condition.

11. The inverter according to any one of claims 1 to 10, wherein The DC surge protection device is connected between the DC port and the ground electrode and is configured to connect the DC port and the ground electrode during startup; The detection device includes a third current detection component, which is configured to be disposed between the DC surge protection device and the ground electrode, and is configured to detect the current flowing through the DC surge protection device and the ground electrode. The controller is configured to turn off each switching device in the inverter circuit when the current flowing between the DC surge protection device and the ground electrode meets the lightning surge conditions.

12. The inverter according to any one of claims 1 to 11, wherein The AC surge protection device is connected between the AC port and the ground electrode and is configured to connect the AC port and the ground electrode during startup; The detection device includes a fourth current detection component, which is configured to be disposed between the AC surge protection device and the ground electrode, and is configured to detect the current flowing through the AC surge protection device and the ground electrode. The controller is configured to turn off each switching device in the inverter circuit when the current flowing between the AC surge protection device and the ground electrode meets the lightning surge condition.

13. The inverter according to any one of claims 1 to 12, wherein The inverter includes an AC filter capacitor, with a first end of the AC filter capacitor connected to the AC port and a second end of the AC filter capacitor connected to the midpoint of the DC bus. The detection device includes a fifth current detection component, which is configured to be connected in series with the AC filter capacitor and configured to detect the current flowing through the AC filter capacitor. The controller is configured to turn off each switching device in the inverter circuit when the current flowing through the AC filter capacitor meets the lightning surge condition.

14. The inverter of claim 13, wherein, The AC port includes multiple AC connection terminals, the inverter includes multiple AC filter capacitors, the first end of each AC filter capacitor is connected to the corresponding AC connection terminal, the second end of each AC filter capacitor is connected to the fourth node, and the fourth node is connected to the midpoint of the DC bus. The fifth current detection component includes a plurality of third current detection elements and / or fourth current detection elements. Each of the third current detection elements is configured to be connected in series with any one of the AC filter capacitors and is configured to detect the current flowing through any one of the AC filter capacitors as the electrical parameter. The fourth current detection element is disposed between the midpoint of the fourth node and the DC bus, and is configured to detect the total current flowing through the multiple AC filter capacitors as the electrical parameter. The controller is configured to turn off each switching device in the inverter circuit when at least one of the parameters, namely the current flowing through any one of the AC filter capacitors and the total current flowing through the multiple AC filter capacitors, satisfies the lightning surge condition.

15. The inverter according to any one of claims 1 to 14, wherein The inverter includes a transformer circuit, the DC port is connected to the input terminal of the transformer circuit, and the output terminal of the transformer circuit is connected to the DC bus. The detection device includes a sixth current detection component, which is configured to be disposed at the input and / or output terminals of the transformer circuit and configured to detect the current information at the input and / or output terminals of the transformer circuit as the electrical parameter. The controller is configured to control each switching device in the inverter circuit to turn off when at least one parameter in the current information at the input or output of the transformer circuit meets the lightning surge condition.

16. The inverter of claim 15, wherein, The sixth current detection component is configured to be connected in series with the input terminal of the transformer circuit, and is configured to detect the current flowing through the input terminal of the transformer circuit as the electrical parameter, and / or The sixth current detection component is configured to be connected in series with the output terminal of the transformer circuit, and is configured to detect the current flowing through the output terminal of the transformer circuit as the electrical parameter; The controller is configured to turn off each switching device in the inverter circuit when at least one of the parameters, the current flowing through the input terminal of the transformer circuit and the current flowing through the output terminal of the transformer circuit, satisfies the lightning surge condition.

17. The inverter according to any one of claims 1 to 16, wherein The controller is configured to: Obtain the electrical parameters of the surge circuit within the inverter; The surge current of the surge circuit is determined based on the electrical parameters of the surge circuit; Before the surge current rises to a first preset current value, the switching devices in the inverter circuit are controlled to turn off, and after the switching devices are turned off, the DC surge protection device and the AC surge protection device are activated.

18. A control method of an inverter, wherein, The inverter includes a DC surge protection device, a DC bus, an inverter circuit, a detection device, and an AC surge protection device. The DC terminal of the inverter circuit is connected to the DC port of the inverter via the DC bus, and the AC terminal of the inverter circuit is connected to the AC port of the inverter. The detection device is configured to be located in the surge circuit of the inverter and is configured to detect the electrical parameters of the surge circuit. The surge circuit is the path for the surge current within the inverter. The method includes: When the electrical parameters detected by the detection device meet the lightning surge conditions, the switching devices in the inverter circuit are controlled to turn off, and after the switching devices are turned off, the DC surge protection device and the AC surge protection device are activated.

19. A photovoltaic energy storage system, wherein, The photovoltaic energy storage system includes the inverter as described in any one of claims 1 to 17.

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