Energy storage inverter circuit, fault judgment method and device, inverter and medium

Abstract

The invention discloses an energy storage inverter circuit, a fault judgment method and device, an inverter and a medium. The fault judgment method comprises the steps of obtaining a first voltage value, a second voltage value, a third voltage value and a fourth voltage value when all relays in two power supply branches are in a closed state; determining the working state of the energy storage inverter circuit according to the first voltage value, the second voltage value, the third voltage value and the fourth voltage value; wherein the second voltage value represents a voltage value sampled by the first signal processing module through the second sampling module, the third voltage value represents a voltage value sampled by the first signal processing module through the third sampling module, and the first voltage value represents a voltage value sampled by the first signal processing module through the first sampling module; and the fourth voltage value represents a voltage value sampled by the second signal processing module through the first sampling module. And the fault condition of the energy storage inverter circuit can be effectively judged.

Description

Technical Field

[0001] The present invention relates to the field of power grid fault judgment, and in particular to an energy storage inverter circuit, a fault judgment method, a device, an inverter and a medium. Background Art

[0002] At present, grid-connected safety regulations in various countries require that relays must be installed between grid-connected inverters and the mains, and redundant protection functions must be met. Relays are important safety devices. If relays fail and are not discovered in time, accidents may occur. In related technologies, the voltage at both ends of the relay group is sampled by a sampling circuit to determine whether the relay is faulty. However, sampling circuit failures and relay failures will both cause voltage abnormalities. Summary of the invention

[0003] The embodiments of the present invention provide an energy storage inverter circuit, a fault judgment method, a device, an inverter, and a medium, which can effectively judge the fault condition of the energy storage inverter circuit.

[0004] In a first aspect, an embodiment of the present invention provides a fault judgment method for an energy storage inverter circuit, wherein the energy storage inverter circuit comprises a first signal processing module, a second signal processing module and two power supply branches, wherein the power supply branch comprises a grid access point, a first relay, a second relay, a third relay and an inverter access point which are arranged in sequence, wherein the grid access point is used to connect to a grid and is connected to a first sampling module, a connection point between the first relay and the second relay is connected to a second sampling module, a connection point between the second relay and the third relay is connected to a third sampling module, and the inverter access point is used to connect to an output end of an inverter, wherein the first sampling module is connected to the first signal processing module and the second signal processing module at the same time, and the second sampling module and the third sampling module are connected to the first signal processing module at the same time;

[0005] The fault judgment method comprises:

[0006] Obtaining a first voltage value, a second voltage value, a third voltage value, and a fourth voltage value when all relays in the two power supply branches are in a closed state;

[0007] Determining a working state of the energy storage inverter circuit according to the first voltage value, the second voltage value, the third voltage value, and the fourth voltage value;

[0008] Among them, the second voltage value represents the voltage value sampled by the first signal processing module through the second sampling module, the third voltage value represents the voltage value sampled by the first signal processing module through the third sampling module, the first voltage value represents the voltage value sampled by the first signal processing module through the first sampling module, and the fourth voltage value represents the voltage value sampled by the second signal processing module through the first sampling module.

[0009] According to the fault judgment method of the energy storage inverter circuit of the first aspect of the present invention, there are at least the following beneficial effects: when all relays in the two power supply branches are in a closed state, if the relay or sampling module in the energy storage inverter circuit does not fail, the voltage difference between the two power supply branches sampled by the signal processing module will not change significantly. Similarly, when a relay or a sampling module in the energy storage inverter circuit fails, it will cause the voltage difference between the fault point and the normal point to change significantly. By sampling the first voltage value between the first relay and the grid access point, the second voltage value between the first relay and the second relay, and the third voltage value between the second relay and the third relay, and then comparing the voltage difference between the first voltage value, the second voltage value, and the third voltage value, it can be determined which position has a fault. In addition, since the first signal processing module and the second signal processing module both sample the voltage value between the first relay and the grid access point through the first sampling module, when the voltage values ​​sampled by the first signal processing module and the second signal processing module are different, it indicates that the first signal processing module or the second signal processing module has a fault. Therefore, the fault condition of the energy storage inverter circuit can be accurately determined by the first voltage value, the second voltage value, the third voltage value and the fourth voltage value.

[0010] In the fault judgment method of the energy storage inverter circuit provided in an embodiment of the present invention, determining the working state of the energy storage inverter circuit according to the first voltage value, the second voltage value, the third voltage value and the fourth voltage value includes:

[0011] When the voltage difference between the first voltage value and the fourth voltage value is greater than a first preset threshold, it is determined whether the first signal processing module and the second signal processing module are in a fault state according to the first voltage value, the second voltage value, the third voltage value and the fourth voltage value.

[0012] In the fault judgment method of the energy storage inverter circuit provided in an embodiment of the present invention, determining whether the first signal processing module and the second signal processing module are in a fault state according to the first voltage value, the second voltage value, the third voltage value, and the fourth voltage value includes:

[0013] When the voltage difference between the first voltage value and the second voltage value is less than or equal to the second preset threshold and the difference between the first voltage value and the third voltage value is less than or equal to the second preset threshold, it is determined that the second signal processing module is in a fault state and the first preset threshold is less than the second preset threshold.

[0014] In the fault judgment method of the energy storage inverter circuit provided in an embodiment of the present invention, the determining whether the first signal processing module and the second signal processing module are in a fault state according to the first voltage value, the second voltage value, the third voltage value, and the fourth voltage value further includes:

[0015] When the difference between the fourth voltage value and the second voltage value is less than or equal to the second preset threshold and the difference between the fourth voltage value and the third voltage value is less than or equal to the second preset threshold, it is determined that the first signal processing module is in a fault state and the first preset threshold is less than the second preset threshold.

[0016] In the fault judgment method of the energy storage inverter circuit provided in an embodiment of the present invention, determining the working state of the energy storage inverter circuit according to the first voltage value, the second voltage value, the third voltage value and the fourth voltage value includes:

[0017] When the voltage difference between the first voltage value and the fourth voltage value is less than or equal to a first preset threshold, it is determined whether each sampling module is in a fault state according to the first voltage value, the second voltage value and the third voltage value.

[0018] In the fault judgment method of the energy storage inverter circuit provided in an embodiment of the present invention, determining whether each sampling module is in a fault state according to the first voltage value, the second voltage value, and the third voltage value includes:

[0019] When the difference between the first voltage value and the second voltage value is greater than a second preset threshold and the voltage difference between the second voltage value and the third voltage value is less than or equal to the second preset threshold, it is determined that the first sampling module is in a fault state, and the first preset threshold is less than the second preset threshold;

[0020] or,

[0021] When the difference between the first voltage value and the second voltage value is greater than the second preset threshold and the voltage difference between the first voltage value and the third voltage value is less than or equal to the second preset threshold, determining that the second sampling module is in a fault state;

[0022] or,

[0023] When the difference between the first voltage value and the third voltage value is greater than the second preset threshold and the voltage difference between the first voltage value and the second voltage value is less than or equal to the second preset threshold, it is determined that the third sampling module is in a fault state.

[0024] In the fault judgment method of the energy storage inverter circuit provided in an embodiment of the present invention, the determining the working state of the energy storage inverter circuit according to the first voltage value, the second voltage value, the third voltage value and the fourth voltage value further includes:

[0025] When the first voltage value and the fourth voltage value are less than or equal to a first preset threshold, and the voltage difference between any two of the first voltage value, the second voltage value and the third voltage value are less than or equal to a second preset threshold, it is determined that the energy storage inverter circuit is in a normal working state, and the first preset threshold is less than the second preset threshold.

[0026] The method for determining a fault in an energy storage inverter circuit provided in an embodiment of the present invention further includes:

[0027] Acquire the first voltage value, the second voltage value, and the third voltage value when the energy storage inverter circuit is in different relay self-test states;

[0028] Determine the working state of each relay according to the first voltage value, the second voltage value and the third voltage value when the energy storage inverter circuit is in different relay self-test states;

[0029] Among them, different relay self-test states indicate that the first relay, the second relay and the third relay in each power supply branch are in different on-off conditions.

[0030] In the second aspect, an embodiment of the present invention provides an energy storage inverter circuit, the energy storage inverter circuit includes a first signal processing module, a second signal processing module and two power supply branches, the power supply branch includes a grid access point, a first relay, a second relay, a third relay and an inverter access point arranged in sequence, the grid access point is used to connect to the grid and is connected to a first sampling module, the connection point between the first relay and the second relay is connected to a second sampling module, the connection point between the second relay and the third relay is connected to a third sampling module, the inverter access point is used to connect to the output end of the inverter, the first sampling module is connected to the first signal processing module and the second signal processing module at the same time, and the second sampling module and the third sampling module are connected to the first signal processing module at the same time. Wherein, the first signal processing module is used to execute the fault judgment method described in the first aspect above; or, the second signal processing module is used to execute the fault judgment method described in the first aspect above; or, it also includes a control module connected to the first signal processing module and the second signal processing module, and the control module is used to execute the fault judgment method described in the first aspect above.

[0031] The energy storage inverter circuit provided according to the embodiment of the present invention has at least the following beneficial effects: when all relays in the two power supply branches are in a closed state, if the relays or sampling modules in the energy storage inverter circuit do not fail, the voltage difference between the two power supply branches sampled by the signal processing module will not change significantly. Similarly, when a relay or a sampling module in the energy storage inverter circuit fails, the voltage difference between the fault point and the normal point will change significantly. By sampling the first voltage value between the first relay and the grid access point, the second voltage value between the first relay and the second relay, and the third voltage value between the second relay and the third relay, and then comparing the voltage difference between the first voltage value, the second voltage value, and the third voltage value, it can be determined which position has a fault. In addition, since the first signal processing module and the second signal processing module both sample the voltage value between the first relay and the grid access point through the first sampling module, when the voltage values ​​sampled by the first signal processing module and the second signal processing module are different, it indicates that the first signal processing module or the second signal processing module has a fault. Therefore, the fault condition of the energy storage inverter circuit can be accurately determined by the first voltage value, the second voltage value, the third voltage value, and the fourth voltage value.

[0032] In a third aspect, an embodiment of the present invention provides an operation control device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the energy storage inverter circuit fault judgment method as described in the embodiment of the first aspect above.

[0033] According to the operation control device provided by the embodiment of the present invention, at least the following beneficial effects are achieved: when all relays in the two power supply branches are in a closed state, if the relays or sampling modules in the energy storage inverter circuit do not fail, the voltage difference between the two power supply branches sampled by the signal processing module will not change significantly. Similarly, when a relay or a sampling module in the energy storage inverter circuit fails, the voltage difference between the fault point and the normal point will change significantly. By sampling the first voltage value between the first relay and the grid access point, the second voltage value between the first relay and the second relay, and the third voltage value between the second relay and the third relay, and then comparing the voltage difference between the first voltage value, the second voltage value, and the third voltage value, it can be determined which position has failed. In addition, since the first signal processing module and the second signal processing module both sample the voltage value between the first relay and the grid access point through the first sampling module, when the voltage values ​​sampled by the first signal processing module and the second signal processing module are different, it indicates that the first signal processing module or the second signal processing module has failed. Therefore, the fault condition of the energy storage inverter circuit can be accurately determined by the first voltage value, the second voltage value, the third voltage value, and the fourth voltage value.

[0034] In a fourth aspect, an embodiment of the present invention provides an inverter, comprising the energy storage inverter circuit described in the embodiment of the second aspect or the operation control device described in the embodiment of the third aspect.

[0035] The inverter provided according to the embodiment of the present invention has at least the following beneficial effects: when all relays in the two power supply branches are in a closed state, if the relay or sampling module in the energy storage inverter circuit does not fail, the voltage difference between the two power supply branches sampled by the signal processing module will not change significantly. Similarly, when a relay or a sampling module in the energy storage inverter circuit fails, the voltage difference between the fault point and the normal point will change significantly. By sampling the first voltage value between the first relay and the grid access point, the second voltage value between the first relay and the second relay, and the third voltage value between the second relay and the third relay, and then comparing the voltage difference between the first voltage value, the second voltage value, and the third voltage value, it can be determined which position has a fault. In addition, since the first signal processing module and the second signal processing module both sample the voltage value between the first relay and the grid access point through the first sampling module, when the voltage values ​​sampled by the first signal processing module and the second signal processing module are different, it indicates that the first signal processing module or the second signal processing module has a fault. Therefore, the fault condition of the energy storage inverter circuit can be accurately determined by the first voltage value, the second voltage value, the third voltage value, and the fourth voltage value.

[0036] In a fifth aspect, an embodiment of the present invention further provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the energy storage inverter circuit fault judgment method as described in the embodiment of the first aspect above.

[0037] The computer-readable storage medium provided according to the embodiment of the present invention has at least the following effects: when all relays in the two power supply branches are in a closed state, if the relay or sampling module in the energy storage inverter circuit does not fail, the voltage difference between the two power supply branches sampled by the signal processing module will not change significantly. Similarly, when a relay or a sampling module in the energy storage inverter circuit fails, the voltage difference between the fault point and the normal point will change significantly. By sampling the first voltage value between the first relay and the grid access point, the second voltage value between the first relay and the second relay, and the third voltage value between the second relay and the third relay, and then comparing the voltage difference between the first voltage value, the second voltage value, and the third voltage value, it can be determined which position has a fault. In addition, since the first signal processing module and the second signal processing module both sample the voltage value between the first relay and the grid access point through the first sampling module, when the voltage values ​​sampled by the first signal processing module and the second signal processing module are different, it indicates that the first signal processing module or the second signal processing module has a fault. Therefore, the fault condition of the energy storage inverter circuit can be accurately determined by the first voltage value, the second voltage value, the third voltage value, and the fourth voltage value.

[0038] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0040] Figure 1 is a partial schematic diagram of an energy storage inverter circuit provided by an embodiment of the present invention;

[0041] Figure 2 is a partial schematic diagram of an energy storage inverter circuit provided by another embodiment of the present invention;

[0042] Figure 3is a flow chart of a method for determining a fault in an energy storage inverter circuit provided by an embodiment of the present invention;

[0043] Figure 4 yes Figure 3 Specific flow chart of step S200;

[0044] Figure 5 yes Figure 4 Specific flow chart of step S210;

[0045] Figure 6 yes Figure 3 Another specific flow chart of step S200;

[0046] Figure 7 yes Figure 6 Specific flow chart of step S220;

[0047] Figure 8 yes Figure 3 Another specific flow chart of step S200;

[0048] Fig. 9 is a flow chart of a method for determining a fault of an energy storage inverter circuit provided by another embodiment of the present invention;

[0049] Fig.10 An embodiment of the present invention provides an operation control device. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0051] It is understood that although the functional modules are divided in the device schematic diagram and the logical order is shown in the flow chart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flow chart. The terms "first", "second", etc. in the specification, claims or the above drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0052] At present, grid-connected safety regulations in various countries require that relays must be installed between grid-connected inverters and the mains, and redundant protection functions must be met. Relays are important safety devices. If relays fail and are not discovered in time, accidents may occur. In related technologies, the voltage at both ends of the relay group is sampled by a sampling circuit to determine whether the relay is faulty. However, sampling circuit failures and relay failures will both cause voltage abnormalities.

[0053] Based on this, the embodiment of the present invention discloses an energy storage inverter circuit, a fault judgment method, an apparatus, an inverter, and a medium. When all relays in two power supply branches are in a closed state, if the relays or sampling modules in the energy storage inverter circuit are not faulty, the voltage difference between the two power supply branches sampled by the signal processing module will not change significantly. Similarly, when a relay or a sampling module in the energy storage inverter circuit fails, the voltage difference between the fault point and the normal point will change significantly. By sampling the first voltage value between the first relay and the grid access point, the second voltage value between the first relay and the second relay, and the third voltage value between the second relay and the third relay, and then comparing the voltage differences between the first voltage value, the second voltage value, and the third voltage value, it can be determined which position has a fault.

[0054] In addition, since the first signal processing module and the second signal processing module both sample the voltage value between the first relay and the grid access point through the first sampling module, when the voltage values ​​sampled by the first signal processing module and the second signal processing module are different, it indicates that the first signal processing module or the second signal processing module has a fault. Therefore, the fault condition of the energy storage inverter circuit can be accurately determined through the first voltage value, the second voltage value, the third voltage value and the fourth voltage value.

[0055] The embodiments of the present invention are further described below in conjunction with the accompanying drawings.

[0056] Reference Figure 1 , Figure 1 It is a partial schematic diagram of an energy storage inverter circuit provided by an embodiment of the present invention.

[0057] It can be understood that the energy storage inverter circuit includes an inverter 100, a power grid 200 and a load output module 300, and the inverter 100 and the power grid 200 are connected by two power supply branches, wherein the two power supply branches include a first power supply branch 400 and a second power supply branch 410, the first power supply branch 400 includes a first relay KA1, a second relay KA2 and a third relay KA3, the second power supply branch 410 includes a fourth relay KA4, a fifth relay KA5 and a sixth relay KA6, the first end of the first relay KA1 is connected to the first power grid access point of the power grid 200, and the first relay KA2 is connected to the first power grid access point of the power grid 200. The second end of KA1 is connected to the first end of the second relay KA2, the second end of the second relay KA2 is connected to the first end of the third relay KA3, the second end of the third relay KA3 is connected to the first inverter 100 access point of the inverter 100, the first end of the fourth relay KA4 is connected to the second grid access point of the power grid 200, the second end of the fourth relay KA4 is connected to the first end of the fifth relay KA5, the second end of the fifth relay KA5 is connected to the first end of the sixth relay KA6, and the second end of the sixth relay KA6 is connected to the second inverter 100 access point of the inverter 100. The connection point between the first end of the first relay KA1 and the first grid access point of the power grid 200 is the first connection point A1, the connection point between the second end of the first relay KA1 and the first end of the second relay KA2 is the second connection point B1, the connection point between the second end of the second relay KA2 and the first end of the third relay KA3 is the first load access point, and a third connection point C1 is also provided between the first load access point and the first end of the third relay KA3. The connection point between the first end of the fourth relay KA4 and the second grid access point of the grid 200 is the fourth connection point A2, the connection point between the second end of the fourth relay KA4 and the first end of the fifth relay KA5 is the fifth connection point B2, the connection point between the second end of the fifth relay KA5 and the first end of the sixth relay KA6 is the second load access point, and a sixth connection point C2 is also provided between the second load access point and the first end of the sixth relay KA6. The load output module 300 is connected to the first load access point and the second load access point respectively. When the inverter 100 circuit is in an off-grid state, the inverter 100 supplies power to the load output module 300 through the first load access point and the second load access point. When the inverter 100 circuit is in a grid-connected state, the inverter 100 and the grid 200 supply power to the load output module 300 through the first load access point and the second load access point.

[0058] Reference Figure 2 , Figure 2 It is a partial schematic diagram of an energy storage inverter circuit provided by another embodiment of the present invention.

[0059] It can be understood that the energy storage inverter circuit further includes a first sampling module 700, a second sampling module 710, a third sampling module 720, a first signal processing module 500 and a second signal processing module 600. The input end of the first sampling module 700 is simultaneously connected to the first connection point A1 and the fourth connection point A2, the output end of the first sampling module 700 is simultaneously connected to the first sampling end of the first signal processing module 500 and the fourth sampling end of the second signal processing module 600, the input end of the second sampling module 710 is simultaneously connected to the second connection point B1 and the fifth connection point B2, the output end of the second sampling module 710 is connected to the second sampling end of the first signal processing module 500, the input end of the third sampling module 720 is simultaneously connected to the third connection point C1 and the sixth connection point C2, and the output end of the third sampling module 720 is connected to the third end of the first signal processing module 500. Among them, the first sampling module 700, the second sampling module 710 and the third sampling module 720 all include a plurality of resistors and amplifiers.

[0060] It should be noted that the first sampling module 700 is connected to the first connection point A1 and the fourth connection point A2 at the same time, so that the first signal processing module 500 and the second signal processing module 600 can sample the voltage value between the power grid 200 and the first relay KA1 and the fourth relay KA4. The second sampling module 710 is connected to the second connection point B1 and the fifth connection point B2 at the same time, so that the first signal processing module 500 can sample the voltage value between the first relay KA1 and the fourth relay KA4 and the second relay KA2 and the fifth relay KA5. The third sampling module 720 is connected to the third connection point C1 and the sixth connection point C2 at the same time, so that the first signal processing module 500 can sample the voltage value between the third relay KA3 and the sixth relay KA6 and the load output module 300.

[0061] It should be noted that when the first sampling module 700 is in a fault state, but the second sampling module 710 and the third sampling module 720 are both in normal working state, the voltage value sampled by the first sampling end of the first signal processing module 500 and the fourth sampling end of the second signal processing module 600 will not be equal to the voltage value sampled by the second sampling end of the first signal processing module 500 and the third sampling end of the first signal processing module 500.

[0062] It should be noted that when the second sampling module 710 is in a fault state, but the first sampling module 700 and the third sampling module 720 are both in normal working state, the voltage value sampled by the second sampling end of the first signal processing module 500 will be unequal to the voltage value sampled by the first sampling end of the first signal processing module 500 and the third sampling end of the first signal processing module 500.

[0063] It should be noted that when the third sampling module 720 is in a fault state, but the first sampling module 700 and the second sampling module 710 are both in a normal working state, the voltage value sampled by the third sampling terminal of the first signal processing module 500 will be different from the voltage values ​​sampled by the first sampling terminal of the first signal processing module 500 and the second sampling terminal of the first signal processing module 500. Therefore, the first signal processing module 500 can determine whether the first sampling module 700, the second sampling module 710 and the third sampling module 720 are in a fault state according to the voltage values ​​sampled by the first sampling terminal, the second sampling terminal and the third sampling terminal.

[0064] It should be noted that since the sampling module is composed of multiple electrical components, when an electrical component in the sampling module fails, the voltage value obtained by the signal processing chip through the faulty sampling module will have a significant deviation from the voltage value obtained by the signal processing chip through the normal sampling module.

[0065] Specifically, other electrical components are included between the first relay KA1 and the first grid access point and between the fourth relay KA4 and the second grid access point. When the electrical components between the first relay KA1 and the first grid access point and between the fourth relay KA4 and the second grid access point fail, it will also cause a deviation between the voltage value sampled by the first sampling end of the first signal processing module 500 and the voltage values ​​sampled by the second sampling end of the first signal processing module 500 and the third sampling end of the first signal processing module 500.

[0066] Specifically, other electrical components are included between the first relay KA1 and the second relay KA2 and between the fourth relay KA4 and the fifth relay KA5. When the electrical components between the first relay KA1 and the second relay KA2 and between the fourth relay KA4 and the fifth relay KA5 fail, it will also cause a deviation between the voltage value sampled by the second sampling end of the first signal processing module 500 and the voltage sampled by the first sampling end of the first signal processing module 500 and the third sampling end of the first signal processing module 500.

[0067] Specifically, other electrical components are included between the third relay KA3 and the first load access point and between the sixth relay KA6 and the second load access point. When the electrical components between the third relay KA3 and the first load access point and between the sixth relay KA6 and the second load access point fail, it will also cause a deviation between the voltage value sampled by the third sampling end of the first signal processing module 500 and the voltage value sampled by the first sampling end of the first signal processing module 500 and the second sampling end of the first signal processing module 500. Therefore, the first signal processing module 500 can determine the fault point in the energy storage inverter circuit based on the voltage values ​​sampled by the first sampling end, the second sampling end, and the third sampling end.

[0068] It can be understood that the first signal processing module 500 and the second signal processing module 600 are connected in communication, so the first signal processing module 500 can also obtain the voltage value sampled by the fourth sampling end of the second signal processing module 600, so that the first signal processing module 500 obtains the voltage values ​​sampled by the first sampling end, the second sampling end, the third sampling end and the fourth sampling end, and then judges the fault condition of the energy storage inverter circuit. In addition, the second signal processing module 600 can also obtain the voltage values ​​sampled by the first sampling end, the second sampling end, the third sampling end and the fourth sampling end through the communication connection with the first signal processing module 500, and then judges the fault condition of the energy storage inverter circuit.

[0069] First, refer to Figure 3 , Figure 3 is a flow chart of a method for determining a fault in an energy storage inverter circuit provided by an embodiment of the present invention. The method for determining a fault in an energy storage inverter circuit can be applied to the above Figure 1 and Figure 2 The energy storage inverter circuit, the fault judgment method includes but is not limited to the following steps:

[0070] Step S100, obtaining a first voltage value, a second voltage value, a third voltage value and a fourth voltage value when all relays in two power supply branches are in a closed state;

[0071] Step S200, determining the working state of the energy storage inverter circuit according to the first voltage value, the second voltage value, the third voltage value and the fourth voltage value.

[0072] It can be understood that when all the relays in the first power supply branch and the second power supply branch are in a closed state, if the relays or sampling modules in the energy storage inverter circuit do not fail, then the voltage values ​​at various points in the energy storage inverter circuit will not change significantly, that is, the voltage value sampled by the first signal processing module through the first sampling module, the voltage value sampled by the first signal processing module through the second sampling module, and the voltage value sampled by the first signal processing module through the third sampling module will not change significantly from each other.

[0073] It should be noted that if a fault occurs in the electrical components or the first sampling module between the first relay and the first grid access point and between the fourth relay and the second grid access point, it will cause a deviation between the voltage value sampled by the first sampling end of the first signal processing module and the voltage values ​​sampled by the second sampling end of the first signal processing module and the third sampling end of the first signal processing module.

[0074] It should be noted that if a fault occurs in the electrical components or the second sampling module between the first relay and the second relay and between the fourth relay and the fifth relay, the voltage value sampled by the second sampling end of the first signal processing module will deviate from the voltage sampled by the first sampling end of the first signal processing module and the third sampling end of the first signal processing module.

[0075] It should be noted that if a fault occurs in the electrical components or the third sampling module between the third relay and the first load access point and between the sixth relay and the second load access point, the voltage value sampled by the third sampling end of the first signal processing module will deviate from the voltage values ​​sampled by the first sampling end of the first signal processing module and the second sampling end of the first signal processing module.

[0076] In addition, since the first signal processing module and the second signal processing module both perform sampling through the first sampling module, if there is a deviation between the voltage value sampled by the first signal processing module through the first sampling module and the voltage value sampled by the second signal processing module through the first sampling module, it indicates that the first sampling module is in a faulty state or the second sampling module is in a faulty state. Therefore, the first voltage value, the second voltage value, the third voltage value and the fourth voltage value when all relays in the first power supply branch and the second power supply branch are in a closed state can be obtained, and then the working state of the energy storage inverter circuit can be determined by the first voltage value, the second voltage value, the third voltage value and the fourth voltage value.

[0077] It should be noted that the first voltage value is a voltage value obtained by the first signal processing module after processing the sampled voltage sampled by the first sampling module, the second voltage value is a voltage value obtained by the first signal processing module after processing the sampled voltage sampled by the second sampling module, the third voltage value is a voltage value obtained by the first signal processing module after processing the sampled voltage sampled by the third sampling module, and the fourth voltage value is a voltage value obtained by the second signal processing module after processing the sampled voltage sampled by the first sampling module.

[0078] It should be noted that the first signal processing module and the second signal processing module can also be connected to the control module, and the control module is used to receive the first voltage value obtained by the first signal processing module after processing the sampled voltage sampled by the first sampling module, the second voltage value obtained by the first signal processing module after processing the sampled voltage sampled by the second sampling module, the third voltage value obtained by the first signal processing module after processing the sampled voltage sampled by the third sampling module, and the fourth voltage value is the voltage value obtained by the second signal processing module after processing the sampled voltage sampled by the first sampling module. The control module judges the working state of the energy storage inverter circuit according to the received first voltage value, second voltage value, third voltage value and fourth voltage value.

[0079] It should be noted that, since the first sampling module is connected to the connection point between the power grid and the first relay and the fourth relay, that is, the first signal processing module and the second signal processing module can sample the voltage input from the power grid through the first sampling module. Therefore, the first signal processing module and the second signal processing module can also determine whether the voltage input from the power grid is normal according to the first voltage value.

[0080] Reference Figure 4 , Figure 4 yes Figure 3 The specific flow chart of step S200 includes but is not limited to the following steps:

[0081] Step S210, when the voltage difference between the first voltage value and the fourth voltage value is greater than the first preset threshold, determine whether the first signal processing module and the second signal processing module are in a fault state according to the first voltage value, the second voltage value, the third voltage value and the fourth voltage value.

[0082] It can be understood that since the first sampling end of the first signal processing module and the fourth sampling end of the second signal processing module both sample the first connection point and the fourth connection point through the first sampling module, if there is no failure in the first signal processing module and the second signal processing module, then the first voltage value sampled by the first signal processing module through the first sampling module and the fourth voltage value sampled by the second signal processing module through the first sampling module are equal, or due to problems such as the sampling accuracy of the first signal processing module and the second signal processing module, there is a small voltage difference between the first voltage value and the fourth voltage value.

[0083] That is, if both the first signal processing module and the second signal processing module are not faulty, then the voltage difference between the first voltage value sampled by the first signal processing module through the first sampling module and the fourth voltage value sampled by the second signal processing module through the first sampling module should be less than or equal to the first preset threshold value, wherein the first preset threshold value is the error value between the first voltage value and the second voltage value. When the voltage difference between the first voltage value and the fourth voltage value is greater than the first preset threshold value, it indicates that the first signal processing module or the second signal processing module is in a faulty state. Since both the first signal processing module and the second signal processing module are sampled through the first sampling module, it is not possible to determine whether the first signal processing module is in a faulty state or the second signal processing module is in a faulty state only through the first voltage value and the fourth voltage value. However, the second signal processing module only samples through the first sampling module, and the first signal processing module also samples through the second sampling module and the third sampling module. When all relays in the first power supply branch and the second power supply branch are in a closed state, the voltage difference between each point on the power supply branch will only fluctuate within a certain amplitude. Therefore, when the voltage difference between the first voltage value and the fourth voltage value is greater than the first preset threshold, it can be judged whether the first signal processing module is in a fault state or the second signal processing module is in a fault state based on the first voltage value, the second voltage value, the third voltage value and the fourth voltage value.

[0084] Reference Figure 5 , Figure 5 yes Figure 4 The specific flow chart of step S210 includes but is not limited to the following steps:

[0085] Step S211, when the voltage difference between the first voltage value and the second voltage value is less than or equal to the second preset threshold and the difference between the first voltage value and the third voltage value is less than or equal to the second preset threshold, determining that the second signal processing module is in a fault state;

[0086] Step S212: when the difference between the fourth voltage value and the second voltage value is less than or equal to the second preset threshold and the difference between the fourth voltage value and the third voltage value is less than or equal to the second preset threshold, it is determined that the first signal processing module is in a fault state.

[0087] It can be understood that when all relays in the first power supply branch and the second power supply branch are in a closed state, if the first power supply branch and the second power supply branch are in a normal working state, the voltage values ​​of each point in the first power supply branch and the second power supply branch are equal, but because the electrical components in the first power supply branch and the second power supply branch may have internal resistance, when all relays in the first power supply branch and the second power supply branch are in a closed state, there may be a voltage difference between the voltage values ​​of each point in the first power supply branch and the second power supply branch. Therefore, when the voltage difference between the first voltage value and the fourth voltage value is greater than the first preset threshold, if only the second signal processing module is in a fault state, and the various ports of the first signal processing module and the electrical components in the first power supply branch and the second power supply branch are not faulty, then the voltage difference between the first voltage value and the second voltage value should be less than or equal to the second preset threshold and the difference between the first voltage value and the third voltage value should be less than or equal to the second preset threshold, wherein the second preset threshold is the error value generated by the internal resistance of the electrical components at each point in the first power supply branch and the second power supply branch. That is, when the voltage difference between the first voltage value and the fourth voltage value is greater than the first preset threshold, the voltage difference between the first voltage value and the second voltage value is less than or equal to the second preset threshold and the difference between the first voltage value and the third voltage value is less than or equal to the second preset threshold, it can be determined that the second signal processing module is in a fault state.

[0088] It should be noted that since there are more electrical components in the first power supply branch and the second power supply branch, that is, the first voltage value, the second voltage value and the third voltage value are more affected by the internal resistance than the first voltage value and the second voltage value, so the first preset threshold is smaller than the second preset threshold.

[0089] It can be understood that when the voltage difference between the first voltage value and the fourth voltage value is greater than the first preset threshold, if only the first sampling end of the first signal processing module is in a fault state, and the second sampling end and the third sampling end of the first signal processing module, the second signal processing module, and the electrical components in the first power supply branch and the second power supply branch are not faulty, then the difference between the fourth voltage value and the second voltage value should be less than or equal to the second preset threshold and the difference between the fourth voltage value and the third voltage value should be less than or equal to the second preset threshold, that is, when the voltage difference between the first voltage value and the fourth voltage value is greater than the first preset threshold, the voltage difference between the fourth voltage value and the second voltage value is less than or equal to the second preset threshold and the difference between the fourth voltage value and the third voltage value is less than or equal to the second preset threshold, it can be determined that the first sampling end of the first signal processing module is in a fault state.

[0090] It should be noted that if the first signal processing module has an internal fault, it may cause errors in the sampling of the first sampling end, the second sampling end and the third sampling end. Therefore, when the voltage difference between the first voltage value and the fourth voltage value is greater than the first preset threshold, the voltage difference between the fourth voltage value and the second voltage value is greater than the second preset threshold, or the difference between the fourth voltage value and the third voltage value is greater than the second preset threshold and the voltage difference between the first voltage value and the second voltage value is greater than the second preset threshold and the difference between the first voltage value and the third voltage value is greater than the second preset threshold, it can be considered that there is an internal fault in the first signal processing module.

[0091] Reference Figure 6 , Figure 6 yes Figure 3 Another specific flow chart of step S200 includes but is not limited to the following steps:

[0092] Step S220: when the voltage difference between the first voltage value and the fourth voltage value is less than or equal to the first preset threshold, determine whether each sampling module is in a fault state according to the first voltage value, the second voltage value and the third voltage value.

[0093] It is understandable that, since both the first signal processing module and the second signal processing module perform sampling through the first sampling module, if the first signal processing module and the second signal processing module are in normal working state, the voltage difference between the first voltage value sampled by the first signal processing module through the first sampling module and the fourth voltage value sampled by the second signal processing module through the first sampling module should be less than the first preset threshold value. When the first signal processing module and the second signal processing module are in normal working state, if any sampling module among the first sampling module, the second sampling module or the third sampling module is in a faulty state, it will cause the voltage value sampled by the signal processing module through the faulty sampling module to be abnormal, but the voltage value sampled by the non-faulty sampling module will not be affected.

[0094] Specifically, when the first sampling module is in a fault state, it will only affect the first voltage value sampled by the first sampling end of the first signal processing module and the fourth voltage value sampled by the fourth sampling end of the fourth sampling module, and will not affect the voltage values ​​sampled by the second sampling end and the third sampling end of the first signal processing module.

[0095] For example, when the second sampling module is in a fault state, it will only affect the second voltage value sampled by the second sampling terminal of the first signal processing module and will not affect the voltage values ​​sampled by the first sampling terminal and the third sampling terminal of the first signal processing module.

[0096] In addition, when the voltage difference between the first voltage value and the fourth voltage value sampled by the second signal processing module through the first sampling module is less than the first preset threshold value, it can be considered that the first voltage value is equal to or close to the fourth voltage value, that is, there is no fault in the first signal processing module and the second signal processing module. Therefore, when the voltage difference between the first voltage value and the fourth voltage value is less than or equal to the first preset threshold value, the first voltage value, the second voltage value and the third voltage value can be used to determine whether each sampling module is in a faulty state.

[0097] Reference Figure 7 , Figure 7 yes Figure 6 The specific flow chart of step S220 includes but is not limited to the following steps:

[0098] Step S221, when the difference between the first voltage value and the second voltage value is greater than the second preset threshold and the voltage difference between the second voltage value and the third voltage value is less than or equal to the second preset threshold, determining that the first sampling module is in a fault state;

[0099] Step S222, when the difference between the first voltage value and the second voltage value is greater than the second preset threshold and the voltage difference between the first voltage value and the third voltage value is less than or equal to the second preset threshold, determining that the second sampling module is in a fault state;

[0100] Step S223: when the difference between the first voltage value and the third voltage value is greater than the second preset threshold and the voltage difference between the first voltage value and the second voltage value is less than or equal to the second preset threshold, it is determined that the third sampling module is in a fault state.

[0101] It can be understood that when the first sampling module is in a fault state, it will only affect the first voltage value sampled by the first sampling end of the first signal processing module and the fourth voltage value sampled by the fourth sampling end of the fourth sampling module, and will not affect the voltage values ​​obtained by the second sampling end and the third sampling end of the first signal processing module, that is, the voltage difference between the second voltage value and the third voltage value will be less than or equal to the second preset threshold.

[0102] Therefore, when the difference between the first voltage value and the second voltage value is greater than the second preset threshold and the voltage difference between the second voltage value and the third voltage value is less than or equal to the second preset threshold, it is determined that the first sampling module is in a fault state.

[0103] It can be understood that when the second sampling module is in a faulty state, it will only affect the second voltage value obtained by the second sampling end of the first signal processing module and will not affect the voltage values ​​obtained by the first sampling end and the third sampling end of the first signal processing module, that is, the voltage difference between the first voltage value and the third voltage value will be less than or equal to the second preset threshold. Therefore, when the difference between the first voltage value and the second voltage value is greater than the second preset threshold and the voltage difference between the first voltage value and the third voltage value is less than or equal to the second preset threshold, it is determined that the second sampling module is in a faulty state.

[0104] It can be understood that when the third sampling module is in a faulty state, it will only affect the third voltage value obtained by the third sampling end of the first signal processing module and will not affect the voltage values ​​obtained by the first sampling end and the second sampling end of the first signal processing module, that is, the voltage difference between the first voltage value and the second voltage value will be less than or equal to the second preset threshold. Therefore, when the difference between the first voltage value and the third voltage value is greater than the second preset threshold and the voltage difference between the first voltage value and the second voltage value is less than or equal to the second preset threshold, it is determined that the third sampling module is in a faulty state.

[0105] Reference Figure 8 , Figure 8 yes Figure 3 Another specific flow chart of step S200 includes but is not limited to the following steps:

[0106] Step S230, when the first voltage value and the fourth voltage value are less than or equal to the first preset threshold, and the voltage difference between any two voltage values ​​among the first voltage value, the second voltage value and the third voltage value is less than or equal to the second preset threshold, it is determined that the energy storage inverter circuit is in a normal working state.

[0107] It can be understood that, when all relays in the first power supply branch and the second power supply branch are in a closed state, if the first power supply branch, the second power supply branch, the first sampling module, the second sampling module, the third sampling module, the first signal processing module and the second signal processing module are all in a normal working state, the first voltage value obtained by the first sampling end of the first signal processing module, the second voltage value obtained by the second sampling end of the first signal processing module and the third voltage value obtained by the third sampling end of the first signal processing module are equal or close, and the first voltage value obtained by the first sampling end of the first signal processing module and the fourth voltage value obtained by the fourth sampling end of the second signal processing module are also equal or close. Therefore, when the first voltage value and the fourth voltage value are less than or equal to the first preset threshold value, and the voltage difference between any two voltage values ​​among the first voltage value, the second voltage value and the third voltage value are less than or equal to the second preset threshold value, it can be determined that the energy storage inverter circuit is in a normal working state.

[0108] Reference Fig. 9 , Fig. 9: is a flow chart of a fault judgment method of an energy storage inverter circuit provided by another embodiment of the present invention, including but not limited to the following steps:

[0109] Step S300, obtaining a first voltage value, a second voltage value, and a third voltage value of the energy storage inverter circuit in different relay self-test states;

[0110] Step S400, determining the working state of each relay according to the first voltage value, the second voltage value and the third voltage value when the energy storage inverter circuit is in different relay self-test states.

[0111] It is understandable that when the energy storage inverter circuit switches from an off-grid state to a grid-connected state, in order to ensure the normal operation of the circuit, it is necessary to perform self-inspection on the first relay, the second relay, the fourth relay and the fifth relay to avoid failure of one or more of the first relay, the second relay, the fourth relay or the fifth relay, resulting in the energy storage inverter circuit being unable to switch normally from an off-grid state to a grid-connected state.

[0112] Since the input end of the second sampling module is simultaneously connected to the first relay and the second relay and the fourth relay and the fifth relay, when the on-off status of the first relay, the second relay, the fourth relay and the fifth relay changes, the voltage value sampled by the first signal processing module through the second sampling module will change, that is, the second voltage value will change with the conduction and cutoff of the first relay, the second relay, the fourth relay and the fifth relay.

[0113] In addition, the input end of the first sampling module is simultaneously connected to the first end of the first relay and the first grid access point of the grid and the first end of the fourth relay and the second grid access point of the grid. When the voltage of the grid input remains unchanged, the first voltage value sampled by the first signal processing module through the first sampling module remains unchanged. Similarly, the input end of the third sampling module is simultaneously connected to the first load access point and the first end of the third relay and the second load access point and the first end of the sixth relay, and when the energy storage inverter circuit is in an off-grid state, the third relay and the sixth relay remain in a conducting state. When the voltage of the inverter input remains unchanged, the third voltage value sampled by the first signal processing module through the third sampling module remains unchanged.

[0114] When the energy storage inverter circuit is in different relay self-test states, the conduction and cutoff conditions of the first relay, the second relay, the fourth relay and the fifth relay are also different. Therefore, the first voltage value, the second voltage value and the third voltage value of the energy storage inverter circuit in different relay self-test states can be taken, and then the working state of each relay can be determined based on the first voltage value, the second voltage value and the third voltage value.

[0115] Specifically, in the self-checking state of the first relay, the first relay, the second relay, the fourth relay and the fifth relay are in the off state at the same time. Since the first relay and the fourth relay are in the off state at the same time, the first relay, the fourth relay and the second sampling module cannot form a current loop, that is, the second voltage value sampled by the first signal processing module through the second sampling module is zero, and the voltage difference between the first voltage value sampled by the first signal processing module through the first sampling module and the second voltage value sampled by the first signal processing module through the second sampling module is greater than the second preset threshold. Similarly, since the second relay and the fifth relay are in the off state at the same time, the second relay, the fifth relay and the second sampling module cannot form a current loop, and the voltage difference between the second voltage value sampled by the first signal processing module through the second sampling module and the third voltage value sampled by the first signal processing module through the third sampling module is greater than the second preset threshold. If the first relay and the fourth relay have the abnormality of contact sticking at the same time, the voltage difference between the first voltage value and the second voltage value will be less than or equal to the second preset threshold; if the second relay and the fifth relay have the abnormality of contact sticking at the same time, the voltage difference between the second voltage value and the third voltage value will be less than or equal to the second preset threshold. Therefore, in the self-test state of the first relay, if the voltage difference between the first voltage value and the second voltage value is less than or equal to the second preset threshold value, it means that the first relay and the fourth relay have the same abnormality of contact sticking; if the voltage difference between the second voltage value and the third voltage value is less than or equal to the second preset threshold value, it means that the second relay and the fifth relay have the same abnormality of contact sticking.

[0116] Specifically, if in the first relay self-checking state, the first relay, the second relay, the fourth relay and the fifth relay are all normal, then the second relay self-checking state is entered, and in the second relay self-checking state, the first relay is controlled to be in the on state, and the second relay, the fourth relay and the fifth relay are controlled to be in the off state. If the fourth relay has an abnormality of contact sticking, it will cause the first relay, the fourth relay and the second sampling module to form a current loop, that is, the voltage difference between the first voltage value and the second voltage value is less than or equal to the second preset threshold value. Therefore, in the second relay self-checking state, if the voltage difference between the first voltage value and the second voltage value is less than or equal to the second preset threshold value, it means that the fourth relay has an abnormality of contact sticking.

[0117] Specifically, if in the second relay self-checking state, the first relay, the second relay, the fourth relay and the fifth relay are all normal, then the third relay self-checking state is entered, and in the third relay self-checking state, the first relay and the fourth relay are controlled to be in the on state at the same time, and the second relay and the fifth relay are controlled to be in the off state at the same time. If the first relay or the fourth relay has a contact non-closing abnormality, it will cause the first relay, the fourth relay and the second sampling module to be unable to form a current loop, that is, the voltage difference between the first voltage value and the second voltage value is greater than the second preset threshold value. Therefore, in the third relay self-checking state, if the voltage difference between the first voltage value and the second voltage value is greater than the second preset threshold value, it means that the fourth relay has a contact non-closing abnormality or the first relay has a contact non-closing abnormality.

[0118] Specifically, if in the third relay self-check state, the first relay, the second relay, the fourth relay and the fifth relay are all normal, then the fourth relay self-check state is entered, and in the fourth relay self-check state, the fourth relay is controlled to be in the on state, and the first relay, the second relay and the fifth relay are controlled to be in the off state. If the first relay has an abnormality of contact sticking, it will cause the first relay, the fourth relay and the second sampling module to form a current loop, that is, the voltage difference between the first voltage value and the second voltage value is less than or equal to the second preset threshold. Therefore, in the fourth relay self-check state, if the voltage difference between the first voltage value and the second voltage value is less than or equal to the second preset threshold, it means that the first relay has an abnormality of contact sticking.

[0119] Specifically, if in the first relay self-checking state, the first relay, the second relay, the fourth relay and the fifth relay are all normal, the fifth relay self-checking state can also be entered. In the fifth relay self-checking state, the second relay is controlled to be in the on state, and the first relay, the fourth relay and the fifth relay are controlled to be in the off state. If the fifth relay has an abnormality of contact sticking, it will cause the second relay, the fifth relay and the second sampling module to form a current loop, that is, the voltage difference between the second voltage value and the third voltage value is less than or equal to the second preset threshold value. Therefore, in the fifth relay self-checking state, if the voltage difference between the second voltage value and the third voltage value is less than or equal to the second preset threshold value, it means that the fifth relay has an abnormality of contact sticking.

[0120] Specifically, if in the fifth relay self-check state, the first relay, the second relay, the fourth relay and the fifth relay are all normal, then the sixth relay self-check state is entered, and in the sixth relay self-check state, the second relay and the fifth relay are controlled to be in the on state at the same time, and the first relay and the fourth relay are controlled to be in the off state. If the second relay or the fifth relay has a contact non-closing abnormality, it will cause the second relay, the fifth relay and the second sampling module to be unable to form a current loop, that is, the voltage difference between the second voltage value and the third voltage value is greater than the second preset threshold value. Therefore, in the sixth relay self-check state, if the voltage difference between the second voltage value and the third voltage value is greater than the second preset threshold value, it means that the second relay has a contact non-closing abnormality or the fifth relay has a contact non-closing abnormality.

[0121] Specifically, if in the sixth relay self-check state, the first relay, the second relay, the fourth relay and the fifth relay are all normal, then the seventh relay self-check state is entered, and in the seventh relay self-check state, the fifth relay is controlled to be in the on state, and the first relay, the second relay and the fourth relay are controlled to be in the off state. If the second relay has an abnormality of contact sticking, it will cause the second relay, the fifth relay and the second sampling module to form a current loop, that is, the voltage difference between the second voltage value and the third voltage value is less than or equal to the second preset threshold. Therefore, in the seventh relay self-check state, if the voltage difference between the second voltage value and the third voltage value is less than or equal to the second preset threshold, it means that the second relay has an abnormality of contact sticking.

[0122] It should be noted that if no abnormality is found in the relay in the first relay self-test state, the second relay self-test state, the third relay self-test state, the fourth relay self-test state, the fifth relay self-test state, the sixth relay self-test state and the seventh relay self-test state, the first relay, the second relay, the fourth relay and the fifth relay are all in normal working condition.

[0123] It should be noted that when the energy storage inverter circuit switches from the shutdown state to the startup state, the third relay and the sixth relay will also be self-checked. Since the relays on the first power supply branch and the second power supply branch are both in the off state when the energy storage inverter circuit is in the shutdown state, that is, the third voltage value is zero. For example, if the energy storage inverter circuit is in the shutdown state, the third voltage value is not zero, indicating that the third relay and the sixth relay have the abnormality of contact sticking at the same time. For another example, when the energy storage inverter circuit switches from the shutdown state to the startup state, the third relay is controlled to be in the on state and the sixth relay is controlled to be in the off state. If the third voltage value is not zero, it indicates that the sixth relay has the abnormality of contact sticking. For another example, when the energy storage inverter circuit switches from the shutdown state to the startup state, the sixth relay is controlled to be in the on state and the third relay is controlled to be in the off state. If the third voltage value is not zero, it indicates that the third relay has the abnormality of contact sticking. For another example, when the energy storage inverter circuit switches from the off state to the on state, the third relay and the sixth relay are controlled to be in the on state at the same time. If the third voltage value is zero, it means that the third relay and the sixth relay both have an abnormal contact failure.

[0124] Thirdly, refer to Fig.10 The embodiment of the present invention provides an operation control device 1000, including a memory 1010, a processor 1020, and a computer program stored in the memory 1010 and executable on the processor 1020. The processor 1020 executes the program to implement the energy storage inverter circuit fault judgment method of the first embodiment, for example, Figure 3 Method steps S100 to S200, Figure 4 In the method step S210, Figure 5 Steps S211 and S212 of the method, Figure 6 Step S220 of the method, Figure 7 Steps S221 to S223 in Figure 8 Step S230 in Fig. 9 The method comprises steps S300 to S400.

[0125] The memory 1010 is a non-transient computer-readable storage medium that can be used to store non-transient software programs and non-transient computer executable programs, such as the energy storage inverter circuit fault judgment method in the above embodiment of the present invention. The processor 1020 implements the energy storage inverter circuit fault judgment method in the above embodiment of the present invention by running the non-transient software program and instructions stored in the memory 1010.

[0126] The memory 1010 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required by at least one function; the data storage area may store data required to execute the fault judgment method of the energy storage inverter circuit in the above embodiment, etc. In addition, the memory 1010 may include a high-speed random access memory 1010, and may also include a non-transient memory 1010, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. It should be noted that the memory 1010 may optionally include a memory 1010 remotely arranged relative to the processor 1020, and these remote memories 1010 may be connected to the terminal via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0127] In a fourth aspect, an embodiment of the present invention provides an inverter, the inverter includes an operation control device 1000 as in the embodiment of the third aspect, when all relays in the two power supply branches are in a closed state, if the relay or sampling module in the energy storage inverter circuit does not fail, the voltage difference between the two power supply branches sampled by the signal processing module will not change significantly, similarly, when a relay or a sampling module in the energy storage inverter circuit fails, it will cause the voltage difference between the fault point and the normal point to change significantly. By sampling the first voltage value between the first relay and the grid access point, the second voltage value between the first relay and the second relay, and the third voltage value between the second relay and the third relay, and then comparing the voltage differences between the first voltage value, the second voltage value, and the third voltage value, it can be determined which position has a fault.

[0128] In addition, since the first signal processing module and the second signal processing module both sample the voltage value between the first relay and the grid access point through the first sampling module, when the voltage values ​​sampled by the first signal processing module and the second signal processing module are different, it indicates that the first signal processing module or the second signal processing module has a fault. Therefore, the fault condition of the energy storage inverter circuit can be accurately determined through the first voltage value, the second voltage value, the third voltage value and the fourth voltage value.

[0129] In a fifth aspect, an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the method for determining a fault of an energy storage inverter circuit according to the first aspect of the embodiment, for example, to execute Figure 3 Method steps S100 to S200, Figure 4 In the method step S210, Figure 5 Steps S211 and S212 of the method, Figure 6 Step S220 of the method, Figure 7 Steps S221 to S223 in Figure 8 Step S230 in Fig. 9 The method comprises steps S300 to S400.

[0130] It will be appreciated by those skilled in the art that all or some of the steps and systems in the methods disclosed above may be implemented as software, firmware, hardware, and appropriate combinations thereof. Some physical components or all physical components may be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or may be implemented as hardware, or may be implemented as an integrated circuit, such as an application specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium or a non-transitory medium and a communication medium or a temporary medium. As a term known to those skilled in the art, a computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information such as computer-readable instructions, data structures, program modules, or other data. Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory, or other memory technologies, CD-ROM, digital versatile disk DVD, or other optical disk storage, magnetic cassettes, magnetic tapes, disk storage, or other magnetic storage devices, or any other medium that may be used to store desired information and may be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically embodies computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0131] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the knowledge scope of ordinary technicians in the technical field without departing from the purpose of the present invention.

Claims

1. A method for determining a fault of an energy storage inverter circuit, characterized in that: The energy storage inverter circuit includes a first signal processing module, a second signal processing module and two power supply branches, the power supply branch includes a grid access point, a first relay, a second relay, a third relay and an inverter access point which are arranged in sequence, the grid access point is used to connect to the grid and is connected to a first sampling module, the connection point between the first relay and the second relay is connected to a second sampling module, the connection point between the second relay and the third relay is connected to a third sampling module, the inverter access point is used to connect to the output end of the inverter, the first sampling module is connected to the first signal processing module and the second signal processing module at the same time, and the second sampling module and the third sampling module are connected to the first signal processing module at the same time; The fault judgment method comprises: Obtaining a first voltage value, a second voltage value, a third voltage value, and a fourth voltage value when all relays in the two power supply branches are in a closed state; Determining a working state of the energy storage inverter circuit according to the first voltage value, the second voltage value, the third voltage value, and the fourth voltage value; Among them, the second voltage value represents the voltage value sampled by the first signal processing module through the second sampling module, the third voltage value represents the voltage value sampled by the first signal processing module through the third sampling module, the first voltage value represents the voltage value sampled by the first signal processing module through the first sampling module, and the fourth voltage value represents the voltage value sampled by the second signal processing module through the first sampling module.

2. The fault diagnosis method according to claim 1, characterized in that: The determining the working state of the energy storage inverter circuit according to the first voltage value, the second voltage value, the third voltage value, and the fourth voltage value includes: When the voltage difference between the first voltage value and the fourth voltage value is greater than a first preset threshold, it is determined whether the first signal processing module and the second signal processing module are in a fault state according to the first voltage value, the second voltage value, the third voltage value and the fourth voltage value.

3. The fault judgment method according to claim 2, characterized in that: The determining, according to the first voltage value, the second voltage value, the third voltage value, and the fourth voltage value, whether the first signal processing module and the second signal processing module are in a fault state comprises: When the voltage difference between the first voltage value and the second voltage value is less than or equal to the second preset threshold and the difference between the first voltage value and the third voltage value is less than or equal to the second preset threshold, it is determined that the second signal processing module is in a fault state and the first preset threshold is less than the second preset threshold.

4. The fault judgment method according to claim 2, characterized in that: The determining, according to the first voltage value, the second voltage value, the third voltage value, and the fourth voltage value, whether the first signal processing module and the second signal processing module are in a fault state further includes: When the difference between the fourth voltage value and the second voltage value is less than or equal to the second preset threshold and the difference between the fourth voltage value and the third voltage value is less than or equal to the second preset threshold, it is determined that the first signal processing module is in a fault state and the first preset threshold is less than the second preset threshold.

5. The fault diagnosis method according to claim 1, characterized in that: The determining the working state of the energy storage inverter circuit according to the first voltage value, the second voltage value, the third voltage value, and the fourth voltage value includes: When the voltage difference between the first voltage value and the fourth voltage value is less than or equal to a first preset threshold, it is determined whether each sampling module is in a fault state according to the first voltage value, the second voltage value and the third voltage value.

6. The fault judgment method according to claim 5, characterized in that: The determining, according to the first voltage value, the second voltage value, and the third voltage value, whether each sampling module is in a fault state includes: When the difference between the first voltage value and the second voltage value is greater than a second preset threshold and the voltage difference between the second voltage value and the third voltage value is less than or equal to the second preset threshold, it is determined that the first sampling module is in a fault state, and the first preset threshold is less than the second preset threshold; or, When the difference between the first voltage value and the second voltage value is greater than the second preset threshold and the voltage difference between the first voltage value and the third voltage value is less than or equal to the second preset threshold, determining that the second sampling module is in a fault state; or, When the difference between the first voltage value and the third voltage value is greater than the second preset threshold and the voltage difference between the first voltage value and the second voltage value is less than or equal to the second preset threshold, it is determined that the third sampling module is in a fault state.

7. The fault judgment method according to claim 1, characterized in that: The determining the working state of the energy storage inverter circuit according to the first voltage value, the second voltage value, the third voltage value and the fourth voltage value further includes: When the first voltage value and the fourth voltage value are less than or equal to a first preset threshold, and the voltage difference between any two of the first voltage value, the second voltage value and the third voltage value are less than or equal to a second preset threshold, it is determined that the energy storage inverter circuit is in a normal working state, and the first preset threshold is less than the second preset threshold.

8. The fault judgment method according to claim 1, characterized in that: The fault judgment method further includes: Acquire the first voltage value, the second voltage value, and the third voltage value when the energy storage inverter circuit is in different relay self-test states; Determine the working state of each relay according to the first voltage value, the second voltage value and the third voltage value when the energy storage inverter circuit is in different relay self-test states; Among them, different relay self-test states indicate that the first relay, the second relay and the third relay in each power supply branch are in different on-off conditions.

9. An energy storage inverter circuit, characterized in that: It comprises a first signal processing module, a second signal processing module and two power supply branches, wherein the power supply branch comprises a grid access point, a first relay, a second relay, a third relay and an inverter access point which are arranged in sequence, wherein the grid access point is used to connect to a grid and is connected to a first sampling module, a connection point between the first relay and the second relay is connected to a second sampling module, a connection point between the second relay and the third relay is connected to a third sampling module, and the inverter access point is used to connect to an output end of an inverter, the first sampling module is simultaneously connected to the first signal processing module and the second signal processing module, and the second sampling module and the third sampling module are simultaneously connected to the first signal processing module; in, The first signal processing module is used to execute the fault judgment method according to any one of claims 1 to 8; or, The second signal processing module is used to execute the fault judgment method according to any one of claims 1 to 8; or, It also includes a control module connected to the first signal processing module and the second signal processing module, and the control module is used to execute the fault judgment method according to any one of claims 1 to 8.

10. An operation control device, characterized in that: The invention comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the fault judgment method according to any one of claims 1 to 8.

11. An inverter, characterized in that: It includes the energy storage inverter circuit as claimed in claim 9 or the operation control device as claimed in claim 10.

12. A computer storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the fault judgment method according to any one of claims 1 to 8.

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