Fault detection method and device, electronic equipment and storage medium

Abstract

The embodiment of the invention provides a fault detection method, device and equipment and a medium, which are applied to an inverter system, the inverter system comprises at least two relay groups, the relay groups are connected in series, any relay group comprises at least two relays, and the relay groups are connected in series. The at least two relays are respectively arranged on different power supply lines of the inverter system; the method comprises the following steps: respectively sending driving signals to relays in each relay group; and generating a fault detection result of each relay based on the input side phase voltage sampling value and the output side phase voltage sampling value of each relay. And the fault detection accuracy is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of power supply, and in particular relates to a fault detection method, device, electronic equipment and storage medium. Background Art

[0002] With the development of power supply technology, the demand for inverters has gradually increased. Inverters can convert direct current into alternating current. In order to avoid safety hazards, one or more relays need to be set between the inverter and the grid to achieve electrical isolation. Correspondingly, if the relay fails, it will bring safety problems. Therefore, how to detect relay faults has become an urgent problem to be solved.

[0003] In current fault detection technology, in order to reduce device costs, multiple relays are often made to use the same drive signal, so that multiple relays are disconnected or closed at the same time, making it impossible to locate the faulty relay, resulting in poor accuracy in relay fault detection. Summary of the invention

[0004] The present invention provides a fault detection method, a device, an electronic device and a storage medium, so as to solve the problem of poor accuracy in fault detection of a relay.

[0005] In order to solve the above-mentioned technical problems, the present invention is achieved as follows:

[0006] In a first aspect, the present invention provides a fault detection method, which is applied to an inverter system, wherein the inverter system includes at least two relay groups, each of the relay groups is connected in series, and any of the relay groups includes at least two relays, and the at least two relays are respectively arranged on different power supply lines of the inverter system; the method includes:

[0007] Sending drive signals to the relays in each of the relay groups respectively;

[0008] Based on the input side phase voltage sampling value and the output side phase voltage sampling value of each relay, a fault detection result of each relay is generated.

[0009] In a second aspect, the present invention provides a fault detection device, which is applied to an inverter system, wherein the inverter system includes at least two relay groups, each of which is connected in series, and any of which includes at least two relays, and the at least two relays are respectively arranged on different power supply lines of the inverter system; the device includes:

[0010] A signal sending module, used for sending driving signals to the relays in each of the relay groups;

[0011] The result generating module is used to generate the fault detection result of each relay based on the input side phase voltage sampling value and the output side phase voltage sampling value of each relay.

[0012] In a third aspect, the present invention provides an electronic device comprising: a processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method described in the first aspect when executing the program.

[0013] In a fourth aspect, the present invention provides a readable storage medium, which, when instructions in the storage medium are executed by a processor of an electronic device, enables the electronic device to execute the method described in the first aspect above.

[0014] The fault detection method provided in the embodiment of the present invention is applied to the inverter system. By making the inverter system include at least two relay groups, each relay group is connected in series, any relay group includes at least two relays, and at least two relays are respectively arranged on different power supply lines of the inverter system, the electrical isolation of the inverter side and the grid end of the inverter system can be improved by increasing the number of relay groups, and the safety regulations can be further met. At the same time, by sending a drive signal to each relay respectively, the problem of poor accuracy of fault detection caused by all relays using the same drive signal can be avoided, and then the fault detection result can be generated through the input side phase voltage sampling value and the output side phase voltage sampling value of each relay, thereby improving the accuracy of relay fault detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 is a flowchart of a fault detection method provided by an embodiment of the present invention;

[0017] Figure 2 is a structural schematic diagram of an inverter system provided by an embodiment of the present invention;

[0018] Figure 3 is a structural schematic diagram of another inverter system provided by an embodiment of the present invention;

[0019] Figure 4 This is a schematic diagram of a control process of a main DSP chip provided by an embodiment of the present invention;

[0020] Figure 5 This is a schematic diagram of a control process of a slave DSP chip provided by an embodiment of the present invention;

[0021] Figure 6 is a structural diagram of a fault detection device provided by an embodiment of the present invention;

[0022] Figure 7 It is a structural diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] Figure 1 1 is a flowchart of a fault detection method provided by an embodiment of the present invention. The method is applied to an inverter system. The inverter system includes at least two relay groups. Each of the relay groups is connected in series. Any of the relay groups includes at least two relays. The at least two relays are respectively arranged on different power supply lines of the inverter system. Figure 1 As shown, the method may include the following steps:

[0025] Step 101: Send a drive signal to each relay in the relay group.

[0026] Step 102: Generate a fault detection result of each relay based on the input side phase voltage sampling value and the output side phase voltage sampling value of each relay.

[0027] With respect to the above steps 101 to 102, the embodiment of the present invention can be applied to any inverter system that has a need for fault detection, which can be a preliminary constructed inverter system, or an inverter system that has an operating abnormality or has been put into operation. It can be configured according to actual needs, and the embodiment of the present invention does not impose any restrictions on this.

[0028] Figure 2 is a structural diagram of an inverter system provided by an embodiment of the present invention, such as Figure 2 As shown, the inverter system may include at least two relay groups, each relay group is connected in series, any relay group includes at least two relays, and at least two relays in the same relay group are respectively arranged on different power supply lines of the inverter system.

[0029] Among them, the above-mentioned power supply line refers to a line used to provide electric energy to the power grid, which usually includes a phase line (live line) and a neutral line (zero line). Different inverter systems contain different numbers of power supply lines. On this basis, for different inverter systems, the number of relays contained in the relay group may be different. For example, in a single-phase inverter system, there is only one live line and one zero line, then any relay group included therein may include two relays. For another example, in a three-phase inverter system, there are three live lines and one zero line, then any relay group included therein may include four relays. For another example, in a split-phase inverter system, there are two live lines and one zero line, then any relay group included therein may include three relays.

[0030] Furthermore, if Figure 2 As shown, each relay group is connected in series, which means that each relay group is connected in series in sequence along the direction from the inverter side to the grid side, so that for any power supply line of the inverter system, the power supply line includes at least two relays connected in series in sequence, and these at least two relays belong to different relay groups respectively.

[0031] The above-mentioned driving signal refers to a signal for controlling the relay to be attracted or disconnected, and may include an attraction signal and / or a disconnection signal. Specifically, the attraction signal can make the relay attracted, so that the relay is turned on, and electric energy can be transmitted through the relay. Correspondingly, the disconnection signal can make the relay disconnect, so that the relay is turned off, so that electric energy cannot be transmitted through the relay.

[0032] Among them, the above-mentioned input side refers to the side of the relay close to the inverter unit (away from the grid end), and correspondingly, the output side refers to the side of the relay away from the inverter unit (close to the grid end). Phase voltage refers to the voltage between the live wire and the neutral wire, so the above-mentioned input side phase voltage sampling value refers to the phase voltage value sampled at the input side of the relay, and the above-mentioned output side phase voltage sampling value refers to the phase voltage value sampled at the output side of the relay. Specifically, the voltage sampling value can be obtained by calculating the average value of a mains power cycle and further calculating the effective value of the AC voltage. Of course, other sampling cycles and sampling methods can also be used, and the embodiments of the present invention are not limited to this.

[0033] It should be noted that as the working time of the relay increases, the relay will be worn out and prone to two types of failures: adhesion and non-attraction. The adhesion failure will cause the relay to be unable to disconnect normally, and correspondingly, the non-attraction failure will cause the relay to be unable to close normally. Therefore, when the relay has the above two failures, it will not be able to perform safe isolation according to the actual electrical isolation requirements, thereby bringing safety hazards. On this basis, since the current working state of the relay can be judged by its input side phase voltage and output side phase voltage, the embodiment of the present invention can generate fault detection results for each relay by sending a drive signal to the relay and based on the input side phase voltage sampling value and the output side phase voltage sampling value.

[0034] Specifically, an embodiment of the present invention can send a pull-in signal or a disconnection signal to a relay, and use a voltage sampling value to compare with a preset threshold, wherein the preset threshold can be obtained by pre-calibrating the inverter system, which may include the voltage sampling value of the relay when it is normally pulled in and normally disconnected. Therefore, based on the comparison result between the voltage sampling value and the preset threshold, it can be determined whether the relay can be normally pulled in and normally disconnected, thereby generating a fault detection result.

[0035] Specifically, the above fault detection result can indicate whether the relay has a fault and the type of fault.

[0036] Optionally, the embodiment of the present invention may further include:

[0037] Step 103: When the fault detection result of any relay indicates that the relay is faulty, output the fault detection result.

[0038] Specifically, when any relay fails, the fault detection result can be directly output, and can be output to a preset display terminal by wire or wirelessly, so that relevant personnel can repair or further process the faulty relay in time. Optionally, when the fault detection result of any relay indicates that the relay is faulty, the embodiment of the present invention can also generate a shutdown signal and send it to the inverter system, so that the inverter system immediately shuts down to avoid damage to the inverter system caused by the faulty relay.

[0039] In summary, the fault detection method provided by the embodiment of the present invention is applied to the inverter system. By making the inverter system include at least two relay groups, each relay group is connected in series, any relay group includes at least two relays, and at least two relays are respectively arranged on different power supply lines of the inverter system, the number of relay groups can be increased to improve the electrical isolation of the inverter side and the grid end of the inverter system, and further meet the requirements of safety regulations. At the same time, by sending a drive signal to each relay respectively, the problem of poor accuracy of fault detection caused by all relays using the same drive signal can be avoided, and then the fault detection result can be generated through the input side phase voltage sampling value and the output side phase voltage sampling value of each relay, thereby improving the accuracy of relay fault detection.

[0040] Optionally, in an embodiment of the present invention, the inverter system is a grid-connected inverter system of a split-phase power grid, and any of the relay groups includes a first subgroup and a second subgroup; the relays included in the first subgroup are located on the first phase line in the power supply line, and the relays included in the second subgroup are respectively located on the second phase line and the neutral line in the power supply line; the relays in each of the above relay groups respectively send drive signals, and the embodiments of the present invention may specifically include:

[0041] S21. Sending drive signals to the first subgroup and the second subgroup in each of the relay groups respectively through at least two control units; wherein any of the relay groups receives a drive signal from one of the control units.

[0042] Among them, the split-phase grid refers to the phase-split operation of the grid, that is, the 240V single-phase electricity is split into two-phase electricity of 120V each with a phase of 180 degrees, so the split-phase inverter system includes three power supply lines, namely: two live wires and one neutral wire. On this basis, any relay group in the embodiment of the present invention includes three relays, which are respectively located on the first phase line, the second phase line and the neutral line. Furthermore, the relays included in the above-mentioned first subgroup are located on the first phase line, and the relays included in the second subgroup are located on the second phase line.

[0043] The grid-connected inverter refers to an electric power device that converts direct current into alternating current and outputs the alternating current to the mains, and is usually used to connect a direct current voltage source and a power grid. The inverter system usually also includes an inverter unit. Furthermore, in the embodiment of the present invention, the relay group is located between the inverter unit and the power grid.

[0044] Among them, the above-mentioned control unit refers to a unit for issuing instructions, which can be a digital signal processing (DSP) chip. The DSP chip can send control instructions to the drive circuit, so that the drive circuit sends a drive signal to the corresponding relay based on the control instructions.

[0045] Specifically, since the driving signal of the relay in the related art is usually controlled by a separate DSP chip, if the DSP chip is in an abnormal state, it is impossible to effectively control the closing or disconnection of the relay, and it is impossible to disconnect the relay from the grid or completely disconnect the connection with the grid in time, which may lead to serious safety risks, and it is impossible to effectively judge the relay failure. On this basis, the embodiment of the present invention can use at least two control units to send a driving signal to the relay group, so that when one of the control units is in an abnormal state, the relay can also be controlled by other control units, thereby ensuring the normal realization of electrical isolation and increasing redundancy. At the same time, at least two groups of relays are controlled by at least two control units, and the first subgroup and the second subgroup are divided, so that the relays in the first subgroup and the second subgroup can be respectively driven individually and mixed with the same drive.

[0046] Specifically, one control unit can control at least one relay group, that is, any relay group receives a driving signal from a control unit, that is, the relays in the same relay group are controlled by the same control unit. This ensures that each control unit can independently control the electrical isolation of the inverter system. When other control units are abnormal, the on and off of all power supply lines can be effectively controlled by one control unit, which can effectively reduce the possibility of safety accidents.

[0047] At the same time, the embodiment of the present invention can send a driving signal to the first subgroup and the second subgroup, so that the relays in the first subgroup receive the same driving signal and the relays in the second subgroup receive the same driving signal, thereby reducing the system design cost while meeting the accuracy requirements of fault detection.

[0048] Optionally, the above-mentioned relay group includes a first relay group, a second relay group and a third relay group, and the first relay group, the second relay group and the third relay group are connected in series in sequence along the direction toward the power grid end; each of the relay groups includes a first relay, a second relay and a third relay, the first relay is located at the first phase line, the second relay is located at the second phase line, and the third relay is located at the neutral line.

[0049] Specifically, in order to reduce the device design cost while meeting the safety requirements, the embodiment of the present invention can set three relay groups in the inverter system, and the three relay groups are connected in series in the direction toward the grid end, namely the first relay group, the second relay group and the third relay group. At the same time, since the inverter system belongs to a split-phase grid, each relay group includes three relays, which are respectively located on the first phase line, the second phase line and the neutral line.

[0050] Figure 3 is a structural diagram of another inverter system provided by an embodiment of the present invention, such as Figure 3 As shown, the inverter system includes a photovoltaic power plant (PV), a non-isolated DC-to-DC converter (DC / DC), a capacitor, an inductor, and an inverter unit. The electric energy output by the inverter unit is split into phases through the inductor and the capacitor, and is transmitted to the grid through the first phase line (L1), the second phase line (L2), and the neutral line (N), so that the grid end can receive AC power.

[0051] like Figure 3 As shown, there are three groups of relays between the inverter unit and the grid end. The first relay group includes Kk1, Kk2 and Kk3, the second relay group includes K1, K2 and K3, and the third relay group includes K4, K5 and K6. Figure 3 S1~S6 in the figure are used to represent the driving signal. Figure 3 It can be seen that the Kk1 relay drive is controlled by S1, the Kk2 and Kk3 relay drives are controlled by S2, the K1 relay drive is controlled by S3, the K2 and K3 relay drives are controlled by S4, the K4 relay drive is controlled by S5, and the K5 and K6 relay drives are controlled by S6.

[0052] Correspondingly, V1 is the input side phase voltage sampling value of relay Kk1, V2 is the input side phase voltage sampling value of relay Kk3, V3 is the output side phase voltage sampling value of relay Kk1, and is also the input side phase voltage sampling value of relay K1, V4 is the output side phase voltage sampling value of relay Kk3, and is also the input side phase voltage sampling value of relay K3, V5 is the output side phase voltage sampling value of relay K1, and is also the input side phase voltage sampling value of relay K4, V6 is the output side phase voltage sampling value of relay K3, and is also the input side phase voltage sampling value of relay K6, V7 is the input side phase voltage sampling value of relay K4, and V8 is the input side phase voltage sampling value of relay K6.

[0053] Optionally, in the embodiment of the present invention, two DSP chips can be set to control the driving signals. For example, driving S1, S2, S3, and S4 can be controlled by the main DSP chip, and driving S5 and S6 can be controlled by the slave DSP chip. Of course, other combinations can also be used, and the embodiment of the present invention does not limit this. On this basis, Figure 4 FIG. 1 is a schematic diagram of a control process of a main DSP chip provided by an embodiment of the present invention. Figure 4 As shown, the main DSP chip can control the relay drive signals S1-S4.

[0054] Alternatively, if Figure 4As shown, the execution subject in the embodiment of the present invention can be the main DSP chip, so that the voltage sampling V1~V8 can be transmitted to the main DSP chip. Figure 3 Taking the inverter system structure in as an example, V1 is the inverter L1 voltage, V2 is the inverter L2 voltage, V3 is the load L1 voltage, V4 is the load L2 voltage, V5 is the middle L1 voltage, V6 is the middle L2 voltage, V7 is the grid L1 voltage, and V8 is the grid L2 voltage.

[0055] Figure 5 FIG. 1 is a schematic diagram of a control process from a DSP chip provided by an embodiment of the present invention. Figure 5 As shown, the relay drive signals S5 and S6 can be controlled from the DSP chip.

[0056] Optionally, the operation of generating the fault detection result of each relay based on the input side phase voltage sampling value and the output side phase voltage sampling value of each relay, in an embodiment of the present invention, may specifically include:

[0057] S31. After sending disconnection signals to the first subgroup and the second subgroup in each of the relay groups respectively, generate a sticking fault detection result for the first relay or the second relay in the third relay group based on the input side phase voltage sampling values ​​of the first relay and the second relay included in the third relay group.

[0058] S32: If neither the first relay nor the second relay in the third relay group has a sticking fault, send a pull-in signal to the first relay in the third relay group.

[0059] S33. Generate a sticking fault detection result for the third relay in the third relay group based on the input side phase voltage sampling value and the output side phase voltage sampling value of the first relay and the input side phase voltage sampling value and the output side phase voltage sampling value of the second relay.

[0060] Specifically, the above steps can be specifically that after sending a disconnection signal to the first sub-group and the second sub-group in each of the relay groups, when the input side phase voltage sampling value of the first relay or the second relay included in the third relay group is not less than the first voltage threshold, a first fault detection result is generated; the first fault detection result indicates that the first relay or the second relay in the third relay group has a adhesion fault.

[0061] When the input side phase voltage sampling value of the first relay or the second relay included in the third relay group is not less than the first voltage threshold, a pull-in signal is sent to the first relay in the third relay group.

[0062] When the voltage difference between the input side phase voltage sampling value and the output side phase voltage sampling value of the first relay is not greater than the second voltage threshold, or the voltage difference between the input side phase voltage sampling value and the output side phase voltage sampling value of the second relay is not greater than the third voltage threshold, a second fault detection result is generated; the second fault detection result indicates that the third relay in the third relay group has a adhesion fault.

[0063] Among them, after sending the disconnection signal to each relay group, all relays should be in the disconnected state, and the inverter unit does not supply power to the relay group. Since the third relay group is close to the grid side, the grid side will supply power to the relay group. At this time, it can be judged whether each relay can be disconnected normally through the phase voltage sampling value of each relay in the third relay group.

[0064] Among them, the first voltage threshold, the second voltage threshold and the third voltage threshold can be obtained by pre-calibration, and can be obtained by pre-detecting the phase voltage of each relay when each relay is in a normally disconnected state. The first voltage threshold, the second voltage threshold and the third voltage threshold can be set according to the actual inverter structure. Exemplarily, in one case, the embodiment of the present invention can set the first voltage threshold to 20V, the second voltage threshold to 10V, and the third voltage threshold to 20V through pre-calibration.

[0065] Specifically, when the input side phase voltage sampling value of the first relay or the second relay included in the third relay group is not less than the first voltage threshold, at this time, Figure 3 The voltage V5 is not less than 20V, or the voltage V6 is not less than 20V. However, when the first relay (K4) or the second relay (K6) included in the third relay group is disconnected, the detected V5 and V6 should be less than 20V. At this time, this condition is not met, indicating that at least one of K4 and K6 has a sticking fault and cannot be disconnected normally.

[0066] Specifically, when the voltage V5 is not less than 20 V, K4 has a sticking fault. Correspondingly, when the voltage V6 is not less than 20 V, K6 has a sticking fault.

[0067] Furthermore, it is possible to continue to determine whether relay K5 has a sticking fault. Specifically, K4 can be closed by sending a pull-in signal to K4. At this time, if K5 is normally disconnected, the difference between V5 and V7 should be greater than the second voltage threshold, and the difference between V6 and V8 should be greater than the third voltage threshold. When this condition is not met, that is, when the difference between V5 and V7 is not greater than the second voltage threshold, or when the difference between V6 and V8 is not greater than the third voltage threshold, it indicates that both K4 and K5 are in a closed state, so it can be determined that K5 has a sticking fault.

[0068] Optionally, the embodiment of the present invention may further include:

[0069] S41: If none of the relays in the third relay group has a sticking fault, a disconnection signal is sent to a first subgroup in the third relay group, and a pull-in signal is sent to a second subgroup in the third relay group.

[0070] S42: Generate a circuit breaker fault detection result for the second relay or the third relay in the third relay group based on the input side phase voltage sampling value and the output side phase voltage sampling value of the second relay.

[0071] S43: If neither the second relay nor the third relay in the third relay group has a circuit breaker fault, send a pull-in signal to the first subgroup in the third relay group.

[0072] S44. Generate a circuit breaker fault detection result for the first relay in the third relay group based on the input side phase voltage sampling value of the first relay in the third relay group.

[0073] Specifically, a disconnection signal may be sent to the first subgroup in the third relay group, and a pull-in signal may be sent to the second subgroup in the third relay group. When the voltage difference between the input side phase voltage sampling value and the output side phase voltage sampling value of the second relay is greater than the fourth voltage threshold, a third fault detection result is generated; the third fault detection result indicates that the second relay or the third relay in the third relay group has a circuit breaker fault.

[0074] When the voltage difference between the input side phase voltage sampling value and the output side phase voltage sampling value of the second relay is greater than the fourth voltage threshold, a pull-in signal is sent to the first subgroup in the third relay group.

[0075] When the input side phase voltage sampling value of the first relay in the third relay group is less than the fifth voltage threshold, a fourth fault detection result is generated; the fourth fault detection result indicates that a circuit breaker fault exists in the first relay in the third relay group.

[0076] Among them, the above-mentioned fourth voltage threshold and fifth voltage threshold can also be obtained by pre-calibration. The fourth voltage threshold can be obtained by pre-detecting the phase voltage of each relay when the first relay in the third relay group is normally disconnected and the second and third relays are normally attracted. Correspondingly, the fifth voltage threshold can be obtained by pre-detecting the phase voltage of each relay when the first relay, the second and the third relays in the third relay group are all normally attracted. It can be set according to the actual inverter structure, and the embodiment of the present invention does not limit this. For example, in one case, the embodiment of the present invention can set the fourth voltage threshold to 30V and the fifth voltage threshold to 180V through pre-calibration.

[0077] Specifically, after sending a disconnection signal to the first subgroup and sending a pull-in signal to the second subgroup, the first relay should be disconnected and the second and third relays should be closed. If there is no fault in the relay, the voltage difference between V6 and V8 should not be greater than the fourth voltage threshold. If the voltage difference between the input side phase voltage sampling value and the output side phase voltage sampling value of the second relay is greater than the fourth voltage threshold, it indicates that at least one of the second and third relays cannot be normally pulled in, that is, there is a circuit breaker fault.

[0078] Furthermore, if the second relay and the third relay do not have a circuit-breaking fault, K5 and K6 can be closed normally at this time, and the fault of K4 can be further determined. After sending the pull-in signal to the first subgroup, the first, second, and third relays should all be in a closed state. If the first relay does not have a fault at this time, the voltage V5 should not be less than the fifth voltage threshold. If it is less than, it indicates that the first relay is in an open state at this time, that is, the first relay has a circuit-breaking fault and cannot be closed normally.

[0079] Optionally, the inverter system further includes an inverter unit, and the operation of generating a fault detection result of each relay based on the input side phase voltage sampling value and the output side phase voltage sampling value of each relay, the embodiment of the present invention may specifically include:

[0080] S51, after sending a disconnection signal to the first subgroup and the second subgroup in each of the relay groups, sending a pull-in signal to the second subgroup in the first relay group, and controlling the output voltage of the inverter unit.

[0081] S52: Generate a sticking fault detection result for the first relay in the first relay group based on the input side phase voltage sampling value and the output side phase voltage sampling value of the first relay in the first relay group.

[0082] S53: If there is no adhesion fault in the first relay of the first relay group, after sending a disconnection signal to the first subgroup and the second subgroup in each of the relay groups respectively, a pull-in signal is sent to the first subgroup in the first relay group, and the output voltage of the inverter unit is controlled.

[0083] S54. Generate a sticking fault detection result for the second relay or the third relay in the first relay group based on the input side phase voltage sampling value and the output side phase voltage sampling value of the second relay in the first relay group and the input side phase voltage sampling value and the output side phase voltage sampling value of the first relay in the first relay group.

[0084] Specifically, the above steps may specifically include: after sending a disconnection signal to the first subgroup and the second subgroup in each relay group respectively, sending a pull-in signal to the second subgroup in the first relay group, and controlling the output voltage of the inverter unit.

[0085] When the voltage difference between the input side phase voltage sampling value and the output side phase voltage sampling value of the first relay in the first relay group is not greater than the sixth voltage threshold, a fifth fault detection result is generated; the fifth fault detection result indicates that the first relay in the first relay group has a adhesion fault.

[0086] When the voltage difference between the input side phase voltage sampling value and the output side phase voltage sampling value of the first relay in the first relay group is greater than the sixth voltage threshold, after sending a disconnection signal to the first subgroup and the second subgroup in each relay group respectively, a pull-in signal is sent to the first subgroup in the first relay group, and the output voltage of the inverter unit is controlled.

[0087] When the voltage difference between the input side phase voltage sampling value and the output side phase voltage sampling value of the second relay in the first relay group is not greater than the seventh voltage threshold, or the voltage difference between the input side phase voltage sampling value and the output side phase voltage sampling value of the first relay in the first relay group is not greater than the seventh voltage threshold, a sixth fault detection result is generated; the sixth fault detection result indicates that the second relay or the third relay in the first relay group has a adhesion fault.

[0088] Among them, the above-mentioned sixth voltage threshold and seventh voltage threshold can also be obtained by pre-calibration. It can be that when the second relay group and the third relay group are disconnected, the second and third relays in the first relay group are normally energized, and the inverter unit outputs the voltage, the phase voltage of the relay is pre-detected to obtain the sixth voltage threshold. Correspondingly, when the second relay group and the third relay group are disconnected, the first relay in the first relay group is normally energized, and the inverter unit outputs the voltage, the phase voltage of the relay is pre-detected to obtain the seventh voltage threshold. It can be set according to the actual inverter structure, and the embodiment of the present invention does not limit this. For example, in one case, when the output voltage of the inverter unit is 240V, the embodiment of the present invention can set the sixth voltage threshold to 30V and the seventh voltage threshold to 30V through pre-calibration.

[0089] Specifically, after sending a disconnection signal to each relay group and sending a pull-in signal to the second subgroup in the first relay group, the first relay should be disconnected, and the second and third relays should be closed. After the inverter unit outputs the voltage, if the relay is not faulty, the voltage difference between V1 and V3 should be greater than the sixth voltage threshold. At this time, if the voltage difference between the input side phase voltage sampling value and the output side phase voltage sampling value of the first relay is not greater than the sixth voltage threshold, it indicates that the first relay is not disconnected, that is, the first relay has a sticking fault.

[0090] Furthermore, if the first relay does not have a sticking fault, Kk1 can be disconnected normally at this time, and the faults of Kk2 and Kk3 can be further determined. After sending a disconnection signal to other relays and a pull-in signal to the first subgroup of the first relay group, the first relay should be in a closed state, and the second and third relays should be in a disconnected state. If the second and third relays do not have a fault at this time, the difference between the voltages V2 and V4 should be greater than the seventh voltage threshold and the difference between V1 and V3 should be greater than the seventh voltage threshold. If one of the two conditions is not met, it indicates that the second relay or the third relay cannot be disconnected normally at this time, that is, the second relay or the third relay has a sticking fault.

[0091] Optionally, after the above step S53, the embodiment of the present invention may further include:

[0092] S61. If none of the relays in the first relay group has a sticking fault, a circuit breaker fault detection result is generated for the second relay or the third relay in the first relay group based on the input side phase voltage sampling value and the output side phase voltage sampling value of the second relay in the first relay group.

[0093] S62. If neither the second relay nor the third relay in the first relay group has a circuit breaker fault, after sending a disconnection signal to the first subgroup and the second subgroup in each of the relay groups respectively, a pull-in signal is sent to the first subgroup and the second subgroup in the first relay group, and the output voltage of the inverter unit is controlled.

[0094] S63. Generate a circuit breaker fault detection result for the first relay in the first relay group based on the input side phase voltage sampling value and the output side phase voltage sampling value of the first relay in the first relay group.

[0095] Specifically, the above steps can be specifically: if the voltage difference between the input side phase voltage sampling value and the output side phase voltage sampling value of the second relay in the first relay group is greater than the seventh voltage threshold, and the voltage difference between the input side phase voltage sampling value and the output side phase voltage sampling value of the first relay in the first relay group is greater than the seventh voltage threshold, and the voltage difference between the input side phase voltage sampling value and the output side phase voltage sampling value of the second relay in the first relay group is not less than the eighth voltage threshold, a seventh fault detection result is generated; the seventh fault detection result indicates that there is a circuit breaker fault in the second relay or the third relay in the first relay group.

[0096] When the voltage difference between the input side phase voltage sampling value and the output side phase voltage sampling value of the second relay in the first relay group is less than the eighth voltage threshold, after sending a disconnection signal to the first subgroup and the second subgroup in each relay group respectively, a pull-in signal is sent to the first subgroup and the second subgroup in the first relay group, and the output voltage of the inverter unit is controlled.

[0097] When the voltage difference between the input side phase voltage sampling value and the output side phase voltage sampling value of the first relay in the first relay group is not less than the ninth voltage threshold, an eighth fault detection result is generated; the eighth fault detection result indicates that there is a circuit breaker fault in the first relay in the first relay group.

[0098] Among them, the above-mentioned eighth voltage threshold and ninth voltage threshold can also be obtained by pre-calibration. It can be that when the second relay group and the third relay group are both disconnected, the second and third relays in the first relay group are normally energized, and the inverter unit outputs the voltage, the phase voltage of the relay is pre-detected to obtain the eighth voltage threshold. Correspondingly, when the second relay group and the third relay group are both disconnected, the first, second, and third relays in the first relay group are normally energized, and the inverter unit outputs the voltage, the phase voltage of the relay is pre-detected to obtain the ninth voltage threshold. It can be set according to the actual inverter structure, and the embodiment of the present invention does not limit this. For example, in one case, when the output voltage of the inverter unit is 240V, the embodiment of the present invention can set the eighth voltage threshold to 180V and the ninth voltage threshold to 180V through pre-calibration.

[0099] Specifically, if the voltage difference between the input side phase voltage sampling value and the output side phase voltage sampling value of the second relay in the first relay group is greater than the seventh voltage threshold, at this time, the first, second, and third relays in the first relay group do not have adhesion faults, and it can be further determined whether there is a circuit breaker fault.

[0100] Specifically, when a pull-in signal is sent to the second subgroup in the first relay group, the second and third relays should be closed normally, and the first relay is disconnected. After controlling the output voltage of the inverter unit, if there is no circuit breakage fault in the second and third relays, the difference between V2 and V4 should be less than the eighth voltage threshold. If not, it indicates that at least one of the second and third relays has a circuit breakage fault.

[0101] Correspondingly, if it is less than, it indicates that the second and third relays do not have a circuit-breaking fault, and the first relay can be further judged at this time. Specifically, when the other relay groups are disconnected and the first relay group receives the pull-in signal, the first, second, and third relays should all be closed at this time, and after controlling the output voltage of the inverter unit, if the first relay does not have a circuit-breaking fault, the difference between V1 and V3 should be less than the ninth voltage threshold. If it is not less than, it indicates that the first relay has a circuit-breaking fault.

[0102] Optionally, the inverter system further includes an inverter unit; the operation of generating a fault detection result of each relay based on the input side phase voltage sampling value and the output side phase voltage sampling value of each relay, the embodiment of the present invention may specifically include:

[0103] S71, after sending a disconnect signal to the first subgroup and the second subgroup in each of the relay groups respectively, control the inverter unit to shut down the output, and send a disconnect signal to the first subgroup in the first relay group, and send a pull-in signal to the first subgroup and the second subgroup in the third relay group, and send a pull-in signal to the second subgroup in the second relay group.

[0104] S72: Generate a sticking fault detection result for the first relay in the second relay group based on the input side phase voltage sampling value of the first relay in the second relay group and the input side phase voltage sampling value of the third relay.

[0105] S73: If the first relay in the second relay group does not have a sticking fault, send a disconnection signal to the second subgroup in the second relay group, and send a pull-in signal to the first subgroup in the second relay group.

[0106] S74. Generate a sticking fault detection result for the second relay or the third relay in the second relay group based on the input side phase voltage sampling value of the first relay in the second relay group, the input side phase voltage sampling value of the third relay, and the input side phase voltage sampling value of the first relay in the second relay group.

[0107] Specifically, the above steps may be: after sending a disconnect signal to the first subgroup and the second subgroup in each relay group respectively, control the inverter unit to shut down the output, and send a disconnect signal to the first subgroup in the first relay group, and send a pull-in signal to the first subgroup and the second subgroup in the third relay group, and send a pull-in signal to the second subgroup in the second relay group.

[0108] When the voltage sum of the input side phase voltage sampling value of the first relay in the second relay group and the input side phase voltage sampling value of the third relay is not less than the tenth voltage threshold, a ninth fault detection result is generated; the ninth fault detection result indicates that there is a adhesion fault in the first relay in the second relay group.

[0109] When the voltage sum of the input side phase voltage sampling value of the first relay in the second relay group and the input side phase voltage sampling value of the third relay is less than the tenth voltage threshold, a disconnect signal is sent to the second subgroup in the second relay group, and a pull-in signal is sent to the first subgroup in the second relay group.

[0110] When the voltage sum of the input side phase voltage sampling value of the first relay in the second relay group and the input side phase voltage sampling value of the third relay is not less than the eleventh voltage threshold, or the input side phase voltage sampling value of the first relay in the second relay group is not less than the twelfth voltage threshold, a tenth fault detection result is generated; the tenth fault detection result indicates that the second relay or the third relay in the second relay group has a adhesion fault.

[0111] Among them, the above-mentioned tenth voltage threshold, eleventh voltage threshold and twelfth voltage threshold can also be obtained by pre-calibration, and the first relay in the first relay group can be normally disconnected, all relays in the third relay group are energized, the second and third relays in the second relay group are energized, and other relays are disconnected, and the inverter unit outputs voltage. The phase voltage of the first relay and the third relay is pre-detected to obtain the tenth voltage threshold. Correspondingly, when the first and third relay groups are disconnected, the second and third relays in the second relay group are disconnected, the first relay in the second relay group is normally energized, and the inverter unit outputs voltage, the phase voltage of the first and third relays is pre-detected to obtain the eleventh voltage threshold and the twelfth voltage threshold, which can be set according to the actual inverter structure, and the embodiment of the present invention does not limit this. For example, in one case, the embodiment of the present invention can set the tenth voltage threshold to 180V, the eleventh voltage threshold to 180V, and the twelfth voltage threshold to 90V through pre-calibration.

[0112] Specifically, after sending a pull-in signal to the first and second sub-groups in the third relay group and the second sub-group in the second relay group sends a pull-in signal, the second and third relays in the second relay group should be closed normally, and all relays in the third relay group are closed. At this time, since the first relay group is disconnected and the inverter unit turns off the output, the grid end will supply power to the relay group. If the first relay does not have a sticking fault, the sum of V3 and V4 should be less than the tenth voltage threshold. If not, it indicates that the first relay has a sticking fault.

[0113] Correspondingly, if it is less than, it indicates that there is no adhesion fault in the first relay, and the second and third relays in the second relay group can be further judged. Specifically, when the other relays are disconnected and the first subgroup of the second relay group receives the pull-in signal, the first relay should be closed at this time, and the second and third relays are disconnected. If there is no adhesion fault in the second and third relays, the sum of V3 and V4 should be less than the eleventh voltage threshold, and V3 is less than the twelfth voltage threshold. If one of them is not met, it indicates that there is a circuit breaker fault in the second relay or the third relay.

[0114] Optionally, the embodiment of the present invention may further include:

[0115] S81. If neither the second relay nor the third relay in the second relay group has a sticking fault, after sending a disconnection signal to the first subgroup and the second subgroup in each of the relay groups respectively, a pull-in signal is sent to the second subgroup in the third relay group, and a pull-in signal is sent to the second subgroup in the second relay group.

[0116] S82. Generate a circuit breaker fault detection result for the second relay or the third relay in the second relay group based on the input side phase voltage sampling value of the first relay in the second relay group and the input side phase voltage sampling value of the third relay.

[0117] S83: If neither the second relay nor the third relay in the second relay group has a circuit breaker fault, send a pull-in signal to the first subgroup in the third relay group, and send a pull-in signal to the first subgroup and the second subgroup in the second relay group.

[0118] S84. Generate a circuit breaker fault detection result for the first relay in the second relay group based on the input side phase voltage sampling value and the output side phase voltage sampling value of the first relay in the second relay group.

[0119] Specifically, the above steps can be specifically: if the voltage sum of the input side phase voltage sampling value of the first relay in the second relay group and the input side phase voltage sampling value of the third relay is less than the eleventh voltage threshold, and the input side phase voltage sampling value of the first relay in the second relay group is less than the twelfth voltage threshold, then after sending a disconnect signal to the first sub-group and the second sub-group in each relay group respectively, a pull-in signal is sent to the second sub-group in the third relay group, and a pull-in signal is sent to the second sub-group in the second relay group.

[0120] When the voltage sum of the input side phase voltage sampling value of the first relay and the input side phase voltage sampling value of the third relay in the second relay group is less than the thirteenth voltage threshold, an eleventh fault detection result is generated; the eleventh fault detection result indicates that there is a circuit breaker fault in the second relay or the third relay in the second relay group.

[0121] If the voltage sum of the input side phase voltage sampling value of the first relay in the second relay group and the input side phase voltage sampling value of the third relay is not less than the thirteenth voltage threshold, a pull-in signal is sent to the first subgroup in the third relay group, and a pull-in signal is sent to the first subgroup and the second subgroup in the second relay group.

[0122] When the voltage sum of the input side phase voltage sampling value and the output side phase voltage sampling value of the first relay in the second relay group is not less than the fourteenth voltage threshold, the twelfth fault detection result is generated; the twelfth fault detection result indicates that there is a circuit breaker fault in the first relay in the second relay group.

[0123] Among them, the above-mentioned thirteenth voltage threshold and fourteenth voltage threshold can also be obtained by pre-calibration. It can be that when the second and third relays in the second and third relay groups are normally energized and the other relays are disconnected, the phase voltages of the first and third relays are pre-detected to obtain the thirteenth voltage threshold. Correspondingly, when the first relay in the third relay group is normally energized, all relays in the second relay group are normally energized, and the other relays are disconnected, the phase voltage of the first relay is pre-detected to obtain the fourteenth voltage threshold. It can be set according to the actual inverter structure, and the embodiment of the present invention does not limit this. For example, in one case, the embodiment of the present invention can set the thirteenth voltage threshold to 30V and the fourteenth voltage threshold to 30V through pre-calibration.

[0124] Specifically, if the voltage sum of the input side phase voltage sampling value of the first relay in the second relay group and the input side phase voltage sampling value of the third relay is less than the eleventh voltage threshold, and the input side phase voltage sampling value of the first relay in the second relay group is less than the twelfth voltage threshold, then the first, second, and third relays in the second relay group do not have adhesion faults, and it can be further determined whether there is a circuit breaker fault.

[0125] Specifically, a pull-in signal is sent to the second subgroup in the second and third relay groups. At this time, the second and third relays in the second and third relay groups should be closed normally, and the first relay is disconnected. If there is no circuit breakage fault in the second and third relays, the sum of V3 and V4 should not be less than the thirteenth voltage threshold. If it is less than, it indicates that at least one of the second and third relays has a circuit breakage fault.

[0126] Correspondingly, if it is not less than, it indicates that there is no circuit-breaking fault in the second and third relays, and the first relay can be further judged at this time. Specifically, when the second relay group receives the pull-in signal and the first subgroup in the third relay group receives the pull-in signal, the first, second and third relays in the third relay group should be closed at this time, and the first, second and third relays in the second relay group should be closed. If there is no circuit-breaking fault in the first relay in the second relay group, the difference between V3 and V35 should not be less than the fourteenth voltage threshold at this time. If it is less than, it indicates that there is a circuit-breaking fault in the first relay and it cannot be normally pulled in.

[0127] In the embodiment of the present invention, by adopting a mixed design of a single drive and the same drive, by sending a disconnect signal or a pull-in signal to the relay respectively, and then comparing the phase voltage sampling value of the relay with the set threshold, the detection result of the relay fault can be obtained, while ensuring the accuracy of the fault detection and saving the device cost.

[0128] Optionally, since there is a device delay in the action of the relay, and sampling in a stable voltage state can further improve accuracy, after sending a disconnection signal or a pull-in signal to any relay in the above text, the next step can be executed after a preset delay. Exemplarily, the above preset time length can be 200ms, 400ms, 500ms, etc., and can be set according to the actual device and circuit structure, and the embodiment of the present invention does not limit this.

[0129] Figure 6 is a structural diagram of a fault detection device provided by an embodiment of the present invention, the device is applied to an inverter system, the inverter system includes at least two relay groups, each of the relay groups is connected in series, any of the relay groups includes at least two relays, and the at least two relays are respectively arranged on different power supply lines of the inverter system;

[0130] like Figure 6 As shown, the device 20 may include:

[0131] A signal sending module 201, used to send a driving signal to each relay in the relay group;

[0132] The result generating module 202 is used to generate the fault detection result of each relay based on the input side phase voltage sampling value and the output side phase voltage sampling value of each relay.

[0133] Optionally, the inverter system is a grid-connected inverter system of a split-phase power grid, and any of the relay groups includes a first subgroup and a second subgroup; the relays included in the first subgroup are located on a first phase line in the power supply line, and the relays included in the second subgroup are respectively located on a second phase line and a neutral line in the power supply line;

[0134] The signal sending module is specifically used for:

[0135] A driving signal is sent to the first subgroup and the second subgroup in each of the relay groups respectively through at least two control units; wherein any of the relay groups receives a driving signal from one of the control units.

[0136] Optionally, the relay group includes a first relay group, a second relay group and a third relay group, and the first relay group, the second relay group and the third relay group are connected in series in sequence along the direction toward the grid end; each of the relay groups includes a first relay, a second relay and a third relay, the first relay is located at the first phase line, the second relay is located at the second phase line, and the third relay is located at the neutral line.

[0137] Optionally, the result generation module includes:

[0138] A first generating submodule is used for generating a sticking fault detection result for the first relay or the second relay in the third relay group based on the input side phase voltage sampling values ​​of the first relay and the second relay included in the third relay group after sending a disconnection signal to the first subgroup and the second subgroup in each of the relay groups respectively;

[0139] A first sending submodule, configured to send a pull-in signal to the first relay in the third relay group if neither the first relay nor the second relay in the third relay group has a sticking fault;

[0140] The second generating submodule is used to generate a sticking fault detection result for the third relay in the third relay group based on the input side phase voltage sampling value, the output side phase voltage sampling value of the first relay, the input side phase voltage sampling value and the output side phase voltage sampling value of the second relay.

[0141] Optionally, the device further comprises:

[0142] A second sending module is used to send a disconnect signal to the first subgroup in the third relay group if none of the relays in the third relay group has a sticking fault, and to send a pull-in signal to the second subgroup in the third relay group;

[0143] A third generating module, configured to generate a circuit breaker fault detection result for the second relay or the third relay in the third relay group based on the input side phase voltage sampling value and the output side phase voltage sampling value of the second relay;

[0144] A third sending module, configured to send a pull-in signal to the first subgroup in the third relay group if neither the second relay nor the third relay in the third relay group has a circuit breaker fault;

[0145] The fourth generating module is used to generate a circuit breaker fault detection result for the first relay in the third relay group based on the input side phase voltage sampling value of the first relay in the third relay group.

[0146] Optionally, the inverter system further includes an inverter unit; and the result generating module further includes:

[0147] a fourth sending submodule, configured to send a closing signal to the second subgroup in the first relay group after sending a disconnection signal to the first subgroup and the second subgroup in each of the relay groups, and to control the output voltage of the inverter unit;

[0148] a fifth generating submodule, configured to generate a sticking fault detection result for the first relay in the first relay group based on the input side phase voltage sampling value and the output side phase voltage sampling value of the first relay in the first relay group;

[0149] a fifth sending submodule, configured to send a pull-in signal to the first subgroup in the first relay group after sending a disconnection signal to the first subgroup and the second subgroup in each of the relay groups respectively if the first relay in the first relay group does not have a sticking fault, and to control the output voltage of the inverter unit;

[0150] The sixth generation submodule is used to generate a adhesion fault detection result for the second relay or the third relay in the first relay group based on the input side phase voltage sampling value, the output side phase voltage sampling value of the second relay in the first relay group, the input side phase voltage sampling value and the output side phase voltage sampling value of the first relay in the first relay group.

[0151] Optionally, the device further comprises:

[0152] a seventh generating module, for generating a circuit breaker fault detection result for the second relay or the third relay in the first relay group based on the input side phase voltage sampling value and the output side phase voltage sampling value of the second relay in the first relay group if none of the relays in the first relay group have a sticking fault;

[0153] a sixth sending module, configured to send a pull-in signal to the first subgroup and the second subgroup in each of the relay groups if neither the second relay nor the third relay in the first relay group has a circuit breaker fault, and to control the output voltage of the inverter unit;

[0154] An eighth generating module is used to generate a circuit breaker fault detection result for the first relay in the first relay group based on the input side phase voltage sampling value and the output side phase voltage sampling value of the first relay in the first relay group.

[0155] Optionally, the inverter system further includes an inverter unit; and the result generating module includes:

[0156] a seventh sending submodule, configured to control the inverter unit to shut down the output after sending a disconnection signal to the first subgroup and the second subgroup in each of the relay groups, and to send a disconnection signal to the first subgroup in the first relay group, and to send a pull-in signal to the first subgroup and the second subgroup in the third relay group, and to send a pull-in signal to the second subgroup in the second relay group;

[0157] a ninth generating submodule, configured to generate a sticking fault detection result for the first relay in the second relay group based on the input side phase voltage sampling value of the first relay in the second relay group and the input side phase voltage sampling value of the third relay;

[0158] an eighth sending submodule, configured to send a disconnection signal to the second subgroup in the second relay group if the first relay in the second relay group does not have a sticking fault, and to send a pull-in signal to the first subgroup in the second relay group;

[0159] The tenth generating submodule is used to generate a sticking fault detection result for the second relay or the third relay in the second relay group based on the input side phase voltage sampling value of the first relay in the second relay group, the input side phase voltage sampling value of the third relay and the input side phase voltage sampling value of the first relay in the second relay group.

[0160] Optionally, the device further comprises:

[0161] a ninth sending module, configured to send a pull-in signal to the second subgroup in the third relay group after sending a disconnection signal to the first subgroup and the second subgroup in each of the relay groups respectively if neither the second relay nor the third relay in the second relay group has a sticking fault, and to send a pull-in signal to the second subgroup in the second relay group;

[0162] an eleventh generating module, configured to generate a circuit breaker fault detection result for the second relay or the third relay in the second relay group based on the input side phase voltage sampling value of the first relay in the second relay group and the input side phase voltage sampling value of the third relay;

[0163] a tenth sending module, configured to send a pull-in signal to the first subgroup in the third relay group if neither the second relay nor the third relay in the second relay group has a circuit-breaking fault, and to send a pull-in signal to the first subgroup and the second subgroup in the second relay group;

[0164] The twelfth generating module is used to generate a circuit breaker fault detection result for the first relay in the second relay group based on the input side phase voltage sampling value and the output side phase voltage sampling value of the first relay in the second relay group.

[0165] In summary, the fault detection device provided in the embodiment of the present invention is applied to the inverter system. By making the inverter system include at least two relay groups, each relay group is connected in series, any relay group includes at least two relays, and at least two relays are respectively arranged on different power supply lines of the inverter system, the number of relay groups can be increased to improve the electrical isolation of the inverter side and the grid end of the inverter system, and further meet the requirements of safety regulations. At the same time, by sending a drive signal to each relay respectively, the problem of poor accuracy of fault detection caused by all relays using the same drive signal can be avoided, and then the fault detection result can be generated through the input side phase voltage sampling value and the output side phase voltage sampling value of each relay, thereby improving the accuracy of relay fault detection.

[0166] The present invention also provides an electronic device, see Figure 7 , including: a processor 301, a memory 302, and a computer program 3021 stored in the memory and executable on the processor, wherein the processor implements the fault detection method of the aforementioned embodiment when executing the program.

[0167] The present invention also provides a readable storage medium, when the instructions in the storage medium are executed by a processor of an electronic device, the electronic device can execute the fault detection method of the aforementioned embodiment.

[0168] As for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0169] The algorithm and display provided herein are not inherently related to any particular computer, virtual system or other device. Various general purpose systems can also be used together with the teachings based on this. According to the above description, it is obvious that the structure required for constructing such systems. In addition, the present invention is not directed to any specific programming language either. It should be understood that various programming languages ​​can be utilized to realize the content of the present invention described herein, and the description of the above specific languages ​​is for disclosing the best mode of the present invention.

[0170] In the description provided herein, a large number of specific details are described. However, it is understood that embodiments of the present invention can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail so as not to obscure the understanding of this description.

[0171] Similarly, it should be understood that in order to streamline the present invention and aid in understanding one or more of the various inventive aspects, in the above description of exemplary embodiments of the present invention, the various features of the present invention are sometimes grouped together into a single embodiment, figure, or description thereof. However, this disclosed method should not be interpreted as reflecting the following intention: that the claimed invention requires more features than the features explicitly recited in each claim. More specifically, as reflected in the claims below, inventive aspects lie in less than all the features of the individual embodiments disclosed above. Therefore, the claims that follow the specific embodiment are hereby expressly incorporated into the specific embodiment, with each claim itself serving as a separate embodiment of the present invention.

[0172] Those skilled in the art will appreciate that the modules in the devices in the embodiments may be adaptively changed and arranged in one or more devices different from the embodiments. The modules or units or components in the embodiments may be combined into one module or unit or component, and in addition they may be divided into a plurality of submodules or subunits or subcomponents. Except that at least some of such features and / or processes or units are mutually exclusive, all features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this manner may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature providing the same, equivalent or similar purpose.

[0173] The various component embodiments of the present invention may be implemented in hardware, or in software modules running on one or more processors, or in a combination thereof. It should be understood by those skilled in the art that a microprocessor or digital signal processor (DSP) may be used in practice to implement some or all of the functions of some or all of the components in the sorting device according to the present invention. The present invention may also be implemented as a device or apparatus program for executing part or all of the methods described herein. Such a program for implementing the present invention may be stored on a computer-readable medium, or may be in the form of one or more signals. Such a signal may be downloaded from an Internet website, or provided on a carrier signal, or provided in any other form.

[0174] It should be noted that the above embodiments illustrate the present invention rather than limit it, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets shall not be construed as a limitation on the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention may be implemented by means of hardware comprising a number of different elements and by means of a suitably programmed computer. In a unit claim enumerating a number of devices, several of these devices may be embodied by the same hardware item. The use of the words first, second, and third, etc., does not indicate any order. These words may be interpreted as names.

[0175] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0176] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

[0177] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A fault detection method, characterized in that: The method is applied to an inverter system, wherein the inverter system comprises at least two relay groups, each of the relay groups is connected in series, any of the relay groups comprises at least two relays, and the at least two relays are respectively arranged on different power supply lines of the inverter system; the method comprises: Sending drive signals to the relays in each of the relay groups respectively; Based on the input side phase voltage sampling value and the output side phase voltage sampling value of each relay, a fault detection result of each relay is generated.

2. The method according to claim 1, characterized in that The inverter system is a grid-connected inverter system of a split-phase power grid, and any of the relay groups includes a first subgroup and a second subgroup; the relays included in the first subgroup are located on the first phase line in the power supply line, and the relays included in the second subgroup are respectively located on the second phase line and the neutral line in the power supply line; The sending of driving signals to the relays in each of the relay groups comprises: A driving signal is sent to the first subgroup and the second subgroup in each of the relay groups respectively through at least two control units; wherein any of the relay groups receives a driving signal from one of the control units.

3. The method according to claim 2, characterized in that The relay groups include a first relay group, a second relay group and a third relay group, which are connected in series in sequence along a direction toward the power grid end; each of the relay groups includes a first relay, a second relay and a third relay, the first relay is located on the first phase line, the second relay is located on the second phase line, and the third relay is located on the neutral line.

4. The method according to claim 3, characterized in that The generating of the fault detection result of each relay based on the input side phase voltage sampling value and the output side phase voltage sampling value of each relay comprises: After sending disconnection signals to the first subgroup and the second subgroup in each of the relay groups, respectively, generating a sticking fault detection result for the first relay or the second relay in the third relay group based on the input side phase voltage sampling values ​​of the first relay and the second relay included in the third relay group; If neither the first relay nor the second relay in the third relay group has a sticking fault, sending a pull-in signal to the first relay in the third relay group; Based on the input side phase voltage sampling value and the output side phase voltage sampling value of the first relay, the input side phase voltage sampling value and the output side phase voltage sampling value of the second relay, a sticking fault detection result is generated for the third relay in the third relay group.

5. The method according to claim 4, characterized in that The method further comprises: If none of the relays in the third relay group has a sticking fault, sending a disconnection signal to the first subgroup in the third relay group, and sending a pull-in signal to the second subgroup in the third relay group; generating a circuit breaker fault detection result for the second relay or the third relay in the third relay group based on the input side phase voltage sampling value and the output side phase voltage sampling value of the second relay; If neither the second relay nor the third relay in the third relay group has a circuit breaker fault, sending a pull-in signal to the first subgroup in the third relay group; Based on the input side phase voltage sampling value of the first relay in the third relay group, a circuit breaker fault detection result is generated for the first relay in the third relay group.

6. The method according to claim 3, characterized in that The inverter system further includes an inverter unit; the fault detection result of each relay is generated based on the input side phase voltage sampling value and the output side phase voltage sampling value of each relay, including: After sending a disconnection signal to the first subgroup and the second subgroup in each of the relay groups, sending a pull-in signal to the second subgroup in the first relay group, and controlling the output voltage of the inverter unit; generating a sticking fault detection result for the first relay in the first relay group based on the input side phase voltage sampling value and the output side phase voltage sampling value of the first relay in the first relay group; If the first relay in the first relay group does not have a sticking fault, after sending a disconnection signal to the first subgroup and the second subgroup in each of the relay groups, sending a pull-in signal to the first subgroup in the first relay group, and controlling the output voltage of the inverter unit; Based on the input side phase voltage sampling value, output side phase voltage sampling value of the second relay in the first relay group, the input side phase voltage sampling value and output side phase voltage sampling value of the first relay in the first relay group, a adhesion fault detection result is generated for the second relay or the third relay in the first relay group.

7. The method according to claim 6, characterized in that After controlling the output voltage of the inverter unit, the method further includes: If none of the relays in the first relay group has a sticking fault, generating a circuit breaker fault detection result for the second relay or the third relay in the first relay group based on the input side phase voltage sampling value and the output side phase voltage sampling value of the second relay in the first relay group; If neither the second relay nor the third relay in the first relay group has a circuit breaker fault, after sending a disconnection signal to the first subgroup and the second subgroup in each of the relay groups, sending a pull-in signal to the first subgroup and the second subgroup in the first relay group, and controlling the output voltage of the inverter unit; Based on the input side phase voltage sampling value and the output side phase voltage sampling value of the first relay in the first relay group, a circuit breaker fault detection result is generated for the first relay in the first relay group.

8. The method according to claim 3, characterized in that The inverter system further includes an inverter unit; the fault detection result of each relay is generated based on the input side phase voltage sampling value and the output side phase voltage sampling value of each relay, including: After sending a disconnect signal to the first subgroup and the second subgroup in each of the relay groups, the inverter unit is controlled to turn off the output, and a disconnect signal is sent to the first subgroup in the first relay group, and a pull-in signal is sent to the first subgroup and the second subgroup in the third relay group, and a pull-in signal is sent to the second subgroup in the second relay group; generating a sticking fault detection result for the first relay in the second relay group based on the input side phase voltage sampling value of the first relay in the second relay group and the input side phase voltage sampling value of the third relay; If the first relay in the second relay group does not have a sticking fault, sending a disconnection signal to the second subgroup in the second relay group, and sending a pull-in signal to the first subgroup in the second relay group; Based on the input side phase voltage sampling value of the first relay in the second relay group, the input side phase voltage sampling value of the third relay, and the input side phase voltage sampling value of the first relay in the second relay group, a sticking fault detection result is generated for the second relay or the third relay in the second relay group.

9. The method according to claim 8, characterized in that The method further comprises: If neither the second relay nor the third relay in the second relay group has a sticking fault, after sending a disconnection signal to the first subgroup and the second subgroup in each of the relay groups, sending a pull-in signal to the second subgroup in the third relay group, and sending a pull-in signal to the second subgroup in the second relay group; generating a circuit breaker fault detection result for the second relay or the third relay in the second relay group based on the input side phase voltage sampling value of the first relay in the second relay group and the input side phase voltage sampling value of the third relay; If neither the second relay nor the third relay in the second relay group has a circuit breaker fault, sending a pull-in signal to the first subgroup in the third relay group, and sending a pull-in signal to the first subgroup and the second subgroup in the second relay group; Based on the input side phase voltage sampling value and the output side phase voltage sampling value of the first relay in the second relay group, a circuit breaker fault detection result is generated for the first relay in the second relay group.

10. A fault detection device, characterized in that: The device is applied to an inverter system, the inverter system includes at least two relay groups, each of the relay groups is connected in series, any of the relay groups includes at least two relays, and the at least two relays are respectively arranged on different power supply lines of the inverter system; the device includes: A signal sending module, used for sending driving signals to the relays in each of the relay groups; The result generating module is used to generate the fault detection result of each relay based on the input side phase voltage sampling value and the output side phase voltage sampling value of each relay.

11. An electronic device, characterized in that: include: A processor, a memory, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method according to any one of claims 1 to 9 when executing the program.

12. A readable storage medium, characterized in that: When the instructions in the storage medium are executed by a processor of an electronic device, the electronic device is enabled to execute the method according to any one of claims 1 to 9.

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