Relay fault detection method and device, electronic equipment and storage medium

Abstract

The invention discloses a relay fault detection method and device, electronic equipment and a storage medium. The relay fault detection method is applied to a three-phase inverter system. The relay fault detection method comprises the following steps: controlling a to-be-detected relay group in a three-phase inverter system to be switched off and controlling an auxiliary relay group to be switched on; wherein the relay group to be tested is a relay group to be tested in the three-phase inverter system, and other relay groups except the relay group to be tested in the three-phase inverter system are auxiliary relay groups; obtaining a midpoint voltage between a bus midpoint of the three-phase inverter system and a neutral point of a power grid, an output voltage of each phase of the three-phase inverter system and a voltage of each phase of the power grid; and according to the neutral-point voltage, the output voltage of each phase of the three-phase inverter system and the voltage of each phase of the power grid, determining whether the relay group to be tested has an adhesion fault. According to the relay fault detection method provided by the embodiment of the invention, the detection method is simple, the detection logicality is high, and the detection accuracy and the detection efficiency can be improved.

Description

Technical Field

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

[0002] Relays are important power devices that realize circuit disconnection and conduction, and are also important devices for protecting the safety of power equipment. Therefore, relays are widely used in power equipment such as inverter systems to disconnect and close inverters and power grids. In actual applications, relays are prone to adhesion failures due to aging.

[0003] However, in the prior art, the relay adhesion fault detection method is complicated and the control logic during relay detection is poor, which also results in low accuracy and efficiency of relay fault detection. Summary of the invention

[0004] The present invention provides a relay fault detection method, device, electronic equipment and storage medium to improve detection accuracy and detection efficiency.

[0005] According to one aspect of the present invention, a relay fault detection method is provided, which is applied to a three-phase inverter system, wherein the three-phase inverter system includes at least one relay group; the relay group is used to control the connection between the three-phase inverter system and a power grid; each phase of the three-phase inverter system is connected to each phase of the power grid in a one-to-one correspondence; the relay fault detection method includes:

[0006] Controlling the relay group to be tested in the three-phase inverter system to be disconnected and controlling the auxiliary relay group to be closed; wherein the relay group to be tested is the relay group to be tested in the three-phase inverter system, and the remaining relay groups in the three-phase inverter system except the relay group to be tested are all auxiliary relay groups;

[0007] Obtaining a midpoint voltage between a bus midpoint of the three-phase inverter system and a neutral point of a power grid, an output voltage of each phase of the three-phase inverter system, and a voltage of each phase of the power grid;

[0008] Whether the relay group to be tested has a sticking fault is determined according to the midpoint voltage, the output voltage of each phase of the three-phase inverter system, and the voltage of each phase of the power grid.

[0009] Optionally, each of the relay groups includes three relays; the specific method for determining whether the relay group to be tested has a sticking fault according to the midpoint voltage, the output voltage of each phase of the three-phase inverter system, and the voltage of each phase of the power grid includes:

[0010] If the midpoint voltage is equal to zero, determining whether a three-point adhesion fault occurs in the relay group to be tested according to the output voltage of each phase of the three-phase inverter system and the voltage of each phase of the power grid;

[0011] If the midpoint voltage is greater than zero or less than zero, it is determined whether a single-point adhesion fault or a two-point adhesion fault occurs in the relay group to be tested according to the midpoint voltage and the voltages of each phase of the power grid.

[0012] Optionally, the three-phase inverter system includes a first output phase, a second output phase and a third output phase; the power grid includes a first phase, a second phase and a third phase; the specific method for determining whether the relay group to be tested has a three-point adhesion fault according to the output voltage of each phase of the three-phase inverter system and the voltage of each phase of the power grid includes:

[0013] If the output voltage of the first output phase is equal to the voltage of the first phase, the output voltage of the second output phase is equal to the voltage of the second phase, and the output voltage of the third output phase is equal to the voltage of the third phase, then a three-point adhesion fault occurs in the relay group to be tested;

[0014] If the output voltage of the first output phase is not equal to the voltage of the first phase, the output voltage of the second output phase is not equal to the voltage of the second phase, and the output voltage of the third output phase is not equal to the voltage of the third phase, then the relay group to be tested does not have a sticking fault.

[0015] Optionally, the relay group to be tested includes a first relay to be tested, a second relay to be tested and a third relay to be tested; the first relay to be tested is connected between the three-phase inverter system and the first phase of the power grid; the second relay to be tested is connected between the three-phase inverter system and the second phase of the power grid; the third relay to be tested is connected between the three-phase inverter system and the third phase of the power grid; the specific method for determining whether the relay group to be tested has a single-point adhesion fault or a two-point adhesion fault according to the midpoint voltage and the voltages of each phase of the power grid includes:

[0016] If the midpoint voltage is equal to the voltage of the first phase, a sticking fault occurs in the first relay to be tested;

[0017] If the midpoint voltage is equal to the voltage of the second phase, a sticking fault occurs in the second relay to be tested;

[0018] If the midpoint voltage is equal to the voltage of the third phase, a sticking fault occurs in the third relay to be tested;

[0019] If the midpoint voltage is equal to half of the negative voltage of the first phase, a sticking fault occurs between the second relay to be tested and the third relay to be tested;

[0020] If the midpoint voltage is equal to half of the negative voltage of the second phase, a sticking fault occurs between the first relay to be tested and the third relay to be tested;

[0021] If the midpoint voltage is equal to half of the negative voltage of the third phase, a sticking fault occurs between the first relay to be tested and the second relay to be tested.

[0022] Optionally, after determining whether the relay group to be tested has a sticking fault according to the midpoint voltage, the output voltage of each phase of the three-phase inverter system, and the voltage of each phase of the power grid, the method further includes:

[0023] Controlling the relay group to be tested to close and controlling the auxiliary relay group to close;

[0024] Re-obtaining the output voltage of each phase of the three-phase inverter system and the voltage of each phase of the power grid;

[0025] Whether the relay group to be tested has a circuit breaker fault is determined based on the re-acquired output voltage of each phase of the three-phase inverter system and the voltage of each phase of the power grid.

[0026] Optionally, the first output phase of the three-phase inverter system is connected to the first phase of the power grid; the second output phase of the three-phase inverter system is connected to the second phase of the power grid; the third output phase of the three-phase inverter system is connected to the third phase of the power grid; the specific method of determining whether the relay group to be tested has a circuit breaker fault according to the output voltage of each phase of the three-phase inverter system and the voltage of each phase of the power grid includes:

[0027] If the voltage of the first output phase reacquired is equal to the voltage of the first phase reacquired, the voltage of the second output phase reacquired is equal to the voltage of the second phase reacquired, and the voltage of the third output phase reacquired is equal to the voltage of the third phase reacquired, then the relay group to be tested does not have a circuit breaker fault;

[0028] If the re-acquired voltage of the first output phase is not equal to the re-acquired voltage of the first phase, a circuit breaker fault occurs in the relay between the first output phase and the first phase;

[0029] If the reacquired voltage of the second output phase is not equal to the reacquired voltage of the second phase, a circuit breaker fault occurs in the relay between the second output phase and the second phase;

[0030] If the re-acquired voltage of the third output phase is not equal to the re-acquired voltage of the third phase, a circuit breaker fault occurs in the relay between the third output phase and the third phase.

[0031] Optionally, a specific method for obtaining the midpoint voltage includes:

[0032] Acquiring the potential of the bus midpoint of the three-phase inverter system and the potential of the neutral point of the power grid;

[0033] The midpoint voltage is calculated according to the potential of the bus midpoint of the three-phase inverter system and the potential of the neutral point of the power grid.

[0034] According to another aspect of the present invention, a relay fault detection device is provided, which is applied to a three-phase inverter system, wherein the three-phase inverter system includes at least one relay group; the relay group is used to control the connection between the three-phase inverter system and the power grid; each phase of the three-phase inverter system is connected to each phase of the power grid in a one-to-one correspondence; the relay fault detection device includes:

[0035] A relay control module, used for controlling the disconnection of the relay group to be tested in the three-phase inverter system and controlling the closing of the auxiliary relay group; wherein the relay group to be tested is the relay group to be tested in the three-phase inverter system, and the remaining relay groups in the three-phase inverter system except the relay group to be tested are all auxiliary relay groups;

[0036] An acquisition module, used to obtain the midpoint voltage between the bus midpoint of the three-phase inverter system and the neutral point of the power grid, the output voltage of each phase of the three-phase inverter system, and the voltage of each phase of the power grid;

[0037] A fault diagnosis module is used to determine whether the relay group to be tested has a sticking fault according to the midpoint voltage, the output voltage of each phase of the three-phase inverter system and the voltage of each phase of the power grid.

[0038] According to another aspect of the present invention, there is also provided an electronic device, the electronic device comprising:

[0039] at least one processor; and

[0040] a memory communicatively connected to the at least one processor; wherein,

[0041] The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the relay fault detection method described in any one of the above embodiments.

[0042] According to another aspect of the present invention, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the relay fault detection method described in any of the above embodiments when executed.

[0043] The embodiment of the present invention determines whether a single-point or two-point adhesion occurs in the three-phase inverter system based on the midpoint voltage between the potential of the busbar midpoint of the three-phase inverter system and the potential of the neutral point of the power grid, and when the midpoint voltage is zero, it determines whether a three-point adhesion occurs in the three-phase inverter system based on the output voltage of each phase of the three-phase inverter system and the voltage of each phase of the power grid. The embodiment of the present invention detects the fault of the relay based on the midpoint voltage between the potential of the busbar midpoint of the three-phase inverter system and the potential of the neutral point of the power grid, the output voltage of each phase of the three-phase inverter system, and the voltage of each phase of the power grid. The detection method is simple, the detection logic is strong, and it is conducive to improving the detection efficiency.

[0044] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0046] Figure 1 is a structural schematic diagram of a three-phase inverter system provided by an embodiment of the present invention;

[0047] Figure 2 is a flow chart of a relay fault detection method provided by an embodiment of the present invention;

[0048] Figure 3 is a flow chart of another relay fault detection method provided by an embodiment of the present invention;

[0049] Figure 4 is a voltage vector diagram provided by an embodiment of the present invention;

[0050] Figure 5 is a flow chart of another relay fault detection method provided by an embodiment of the present invention;

[0051] Figure 6 is a schematic diagram of a relay fault detection device provided by an embodiment of the present invention;

[0052] Figure 7 It is a structural schematic diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0053] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0054] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0055] An embodiment of the present invention provides a relay fault detection method. The relay fault detection method can be applied to a three-phase inverter system. The three-phase inverter system includes at least one relay group, and each phase of the three-phase inverter system is connected to each phase of the power grid in a one-to-one correspondence, and the relay group is used to control the connection between the three-phase inverter system and the power grid. In addition, the three-phase inverter system also includes at least one control module, which is used to execute the relay fault detection method provided by any embodiment of the present invention. In order to facilitate the understanding of the relay fault detection method provided by an embodiment of the present invention, the electrical structure of the three-phase inverter system to which the relay fault detection method is applied is first described.

[0056] Figure 1 Schematic diagram of a three-phase inverter system provided by an embodiment of the present invention. Figure 1 The three-phase inverter system includes: a control module 110, an inverter module 120, a filter module 130, a switch module 140 and a grid-connected stabilization module 150. The switch module 140 includes at least one relay group 141. Each relay group 141 includes three relays, and each relay in the same relay group 141 is connected to a different phase. Each relay in the switch module 140 is connected to the control module 110.

[0057] Continue to refer to Figure 1, the inverter module 120, the filter module 130, the switch module 140 and the grid-connected stabilization module 150 are connected in sequence. Among them, the inverter module 120 includes a plurality of switch tubes. The filter module 130 includes: a first inductor L1, a second inductor L2, a third inductor L3, a first capacitor C1, a second capacitor C2 and a third capacitor C3. The switch module 140 includes two relay groups 141. The grid-connected stabilization module 150 includes: a first resistor R1, a second resistor R2 and a third resistor R3. It should be noted that the first relay group 141 includes: a first relay RY1, a second relay RY2, and a third relay RY3; the second relay group 141 includes: a fourth relay RY4, a fifth relay RY5 and a sixth relay RY6.

[0058] The first end of the first inductor L1 is connected to the inverter module 120, the second end of the first inductor L1 is connected to the first end of the first relay RY1, the second end of the first relay RY1 is connected to the first end of the fourth relay RY4, the second end of the fourth relay RY4 is connected to the first phase GIRD-R of the power grid, the first end of the first capacitor C1 is connected to the second end of the first inductor L1; the second end of the first capacitor C1 is connected to the bus midpoint BUSN of the inverter module 120, the first end of the first resistor R1 is connected to the second end of the fourth relay RY4, and the second end of the first resistor R1 is connected to the neutral point GIRD-N of the power grid; the first end of the second inductor L2 is connected to the inverter module 120, the second end of the second inductor L2 is connected to the first end of the second relay RY2, the second end of the second relay RY2 is connected to the first end of the fifth relay RY5, the second end of the fifth relay RY5 is connected to the second phase GIRD-S of the power grid, and the The first end of the second capacitor C2 is connected to the second end of the second inductor L2; the second end of the second capacitor C2 is connected to the bus midpoint BUSN of the inverter module 120, the first end of the second resistor R2 is connected to the second end of the fifth relay RY5, and the second end of the second resistor R2 is connected to the neutral point GIRD-N of the power grid; the first end of the third inductor L3 is connected to the inverter module 120, the second end of the third inductor L3 is connected to the first end of the third relay RY3, the second end of the third relay RY3 is connected to the first end of the sixth relay RY6, the second end of the sixth relay RY6 is connected to the third phase GIRD-T of the power grid, the first end of the third capacitor C3 is connected to the second end of the third inductor L3; the second end of the third capacitor C3 is connected to the bus midpoint BUSN of the inverter module 120, the first end of the third resistor R3 is connected to the second end of the sixth relay RY6, and the second end of the third resistor R3 is connected to the neutral point GIRD-N of the power grid. The first relay RY1, the second relay RY2, the third relay RY3, the fourth relay RY4, the fifth relay RY5 and the sixth relay RY6 are also connected to the control module 110.

[0059] The control module 110 is used to control the opening or closing of the first relay RY1 , the second relay RY2 , the third relay RY3 , the fourth relay RY4 , the fifth relay RY5 and the sixth relay RY6 .

[0060] The embodiment of the present invention also provides a relay fault detection method. The method is applicable to a three-phase inverter system for relay fault detection. The fault detection method can be executed by a relay fault detection device, which can be implemented by software and / or hardware, and the device can be integrated in a control module of the three-phase inverter system. The control module performs fault detection on the relay in the three-phase inverter system by executing the relay fault detection method. The following embodiment will specifically illustrate the relay fault detection method executed by the control module.

[0061] Figure 2 1 is a flow chart of a relay fault detection method provided by an embodiment of the present invention. Figure 2 , the relay fault detection method comprises:

[0062] S110, controlling the relay group to be tested in the three-phase inverter system to be disconnected and controlling the auxiliary relay group to be closed; wherein, the relay group to be tested is the relay group to be tested in the three-phase inverter system, and the remaining relay groups in the three-phase inverter system except the relay group to be tested are all auxiliary relay groups.

[0063] Specifically, refer to Figure 1 , taking the first relay group as the relay group to be tested and the second relay group as the auxiliary relay group as an example. Exemplarily, the control module generates a closing instruction and an opening instruction respectively. The first relay group obtains an opening instruction, and the second relay group obtains a closing instruction, and the first relay group and the second relay group respectively act according to the instructions they obtain. At this time, under ideal conditions, the relay group to be tested (the first relay group) is in an open state, and the auxiliary relay group (the second relay group) is in a closed state. It should be noted that when there are multiple relay groups in the three-phase inverter system, when fault detection is performed on each relay in the three-phase inverter system, there is one and only one group of relay groups to be tested in the three-phase inverter system, and the rest are auxiliary relay groups.

[0064] S120, obtaining a midpoint voltage between a bus midpoint of a three-phase inverter system and a neutral point of a power grid, an output voltage of each phase of the three-phase inverter system, and a voltage of each phase of the power grid.

[0065] Specifically, the bus midpoint of the three-phase inverter system is the bus midpoint of the inverter module in the three-phase inverter system. Among them, the bus midpoint of the three-phase inverter system can be calculated by the potential of the bus midpoint of the three-phase inverter system (the bus midpoint of the inverter module) and the potential of the neutral point of the power grid. It should be noted that the potential of the bus midpoint of the three-phase inverter system and the potential of the neutral point of the power grid can be obtained by detection or calculation, and the potential of the bus midpoint of the three-phase inverter system and the potential of the neutral point of the power grid are obtained in a variety of ways. In actual application, different acquisition methods can be selected according to actual needs, and this embodiment does not limit this.

[0066] Exemplarily, the output voltage of each phase of the three-phase inverter system and the voltage of each phase of the power grid can be obtained by a voltage detection device. Among them, the output voltage of each phase of the three-phase inverter system is the voltage of each output phase of the three-phase inverter system relative to the bus midpoint of the three-phase inverter system; the voltage of each phase of the power grid is the voltage of each phase of the power grid relative to the neutral point of the power grid. It should be noted that the three-phase inverter system has three output phases, which are the first output phase, the second output phase and the third output phase. Specifically, the voltage of the first output phase of the three-phase inverter system is the voltage of one end of the first inductor connected to the first relay relative to the bus midpoint of the three-phase inverter system, that is, the voltage across the first capacitor; the voltage of the second output phase of the three-phase inverter system is the voltage of one end of the second inductor connected to the second relay relative to the bus midpoint of the three-phase inverter system, that is, the voltage across the second capacitor; the voltage of the third output phase of the three-phase inverter system is the voltage of one end of the third inductor connected to the third relay relative to the bus midpoint of the three-phase inverter system, that is, the voltage across the third capacitor.

[0067] S130, determining whether a sticking fault occurs in the relay group to be tested according to the midpoint voltage, the output voltage of each phase of the three-phase inverter system, and the voltage of each phase of the power grid.

[0068] Specifically, continue to refer to Figure 1, when the three-phase inverter system does not have a sticking fault, since the relay to be tested is in a disconnected state at this time, there is no connection between the three-phase inverter system and the power grid, and the output of the three-phase inverter system is alternating current, the first capacitor, the second capacitor and the third capacitor will not be charged, and the voltage of the first output phase, the voltage of the second output phase and the voltage of the third output phase of the three-phase inverter system are equal and all zero. In addition, there is no connection between the three-phase inverter system and the power grid, the potential of the bus midpoint of the three-phase inverter system is equal to the potential of the neutral point of the power grid, and the midpoint voltage is zero. It should be noted that in actual applications, the potential of the bus midpoint of the three-phase inverter system may have a suspended voltage. Therefore, when determining the potential of the bus midpoint of the three-phase inverter system, the suspended voltage should be subtracted to obtain the actual potential of the bus midpoint of the three-phase inverter system. When the three relays of the relay to be tested in the three-phase inverter system are all stuck, at this time, each phase of the three-phase inverter system is connected to each phase of the power grid one by one, the potential of the busbar midpoint of the three-phase inverter system is equal to the potential of the neutral point of the power grid, and the midpoint voltage is zero, but at this time the voltage of each phase of the three-phase inverter system is also the same as the voltage of each phase of the power grid. Whether the three relays in the relay group to be tested of the three-phase inverter system have all had sticking faults can be judged based on this.

[0069] When one or two of the three relays of the relay group to be tested of the three-phase inverter system have a sticking fault, since one or two phases of the three-phase inverter system are connected to the power grid at this time, the potential of the busbar midpoint of the three-phase inverter system deviates from the potential of the neutral point of the power grid. Therefore, when the midpoint voltage is not equal to zero, the relay group to be tested of the three-phase inverter system has a sticking fault. Among them, whether one or two of the three relays of the relay group to be tested of the three-phase inverter system have a sticking fault can be judged based on the comparison of the midpoint voltage with the voltage of each phase of the power grid.

[0070] The embodiment of the present invention determines whether a single-point or two-point adhesion occurs in the three-phase inverter system based on the midpoint voltage between the potential of the busbar midpoint of the three-phase inverter system and the potential of the neutral point of the power grid, and when the midpoint voltage is zero, it determines whether a three-point adhesion occurs in the three-phase inverter system based on the output voltage of each phase of the three-phase inverter system and the voltage of each phase of the power grid. The embodiment of the present invention detects the fault of the relay based on the midpoint voltage between the potential of the busbar midpoint of the three-phase inverter system and the potential of the neutral point of the power grid, the output voltage of each phase of the three-phase inverter system, and the voltage of each phase of the power grid. The detection method is simple and the detection logic is strong, which is conducive to improving the detection accuracy and detection efficiency.

[0071] Figure 3It is a flow chart of another relay fault detection method provided by an embodiment of the present invention. Each relay group includes three relays; the power grid includes a first phase, a second phase and a third phase; the relay group to be tested includes a first relay to be tested, a second relay to be tested and a third relay to be tested; the first relay to be tested is connected between the three-phase inverter system and the first phase of the power grid; the second relay to be tested is connected between the three-phase inverter system and the second phase of the power grid; the third relay to be tested is connected between the three-phase inverter system and the third phase of the power grid. Wherein, continue to refer to Figure 1 , taking the first relay group as the relay group to be tested as an example, the first relay is used as the first relay to be tested, the second relay is used as the second relay to be tested, and the third relay is used as the third relay to be tested.

[0072] Based on the above embodiment, optionally, refer to Figure 3 The specific method of determining whether the relay group to be tested has a sticking fault according to the midpoint voltage, the output voltage of each phase of the three-phase inverter system and the voltage of each phase of the power grid includes:

[0073] S131, determine whether the midpoint voltage is equal to zero; if so, execute S132; if not, execute S133.

[0074] Specifically, when there is no adhesion fault in the three-phase inverter system, since the relay to be tested is in a disconnected state at this time, there is no connection between the three-phase inverter system and the power grid, the potential of the busbar midpoint of the three-phase inverter system is equal to the potential of the neutral point of the power grid, and the midpoint voltage is zero. When the three relays of the relay to be tested in the three-phase inverter system are all adhered, at this time, each phase of the three-phase inverter system is connected to each phase of the power grid one by one, and the potential of the busbar midpoint of the three-phase inverter system is also equal to the potential of the neutral point of the power grid. At this time, it can be determined whether the relay group to be tested has a three-point adhesion fault based on the output voltage of each phase of the three-phase inverter system and the voltage of each phase of the power grid.

[0075] When one or two of the three relays in the relay group to be tested of the three-phase inverter system have a sticking fault, since one or two phases of the three-phase inverter system are connected to the power grid at this time, the potential of the busbar midpoint of the three-phase inverter system deviates from the potential of the neutral point of the power grid, and the midpoint voltage is not equal to zero. At this time, it can be determined whether the relay group to be tested has a single-point sticking fault or a two-point sticking fault based on the midpoint voltage and the voltage of each phase of the power grid.

[0076] S132. Determine whether a three-point adhesion fault occurs in the relay group to be tested according to the output voltage of each phase of the three-phase inverter system and the voltage of each phase of the power grid.

[0077] Specifically, on the basis of the midpoint voltage being zero, when the output voltage of the first output phase is equal to the voltage of the first phase, the output voltage of the second output phase is equal to the voltage of the second phase, and the output voltage of the third output phase is equal to the voltage of the third phase, it indicates that the phases of the three-phase inverter system are connected one by one to the phases of the power grid, and a three-point adhesion fault occurs in the relay group to be tested; when the output voltage of the first output phase is not equal to the voltage of the first phase, the output voltage of the second output phase is not equal to the voltage of the second phase, and the output voltage of the third output phase is not equal to the voltage of the third phase, it indicates that there is no connection between the three-phase inverter system and the power grid, and no adhesion fault occurs in the relay group to be tested.

[0078] S133. Determine whether a single-point adhesion fault or a two-point adhesion fault occurs in the relay group to be tested according to the midpoint voltage and the voltage of each phase of the power grid.

[0079] Specifically, when one or two phases of the three-phase inverter system are connected to the power grid, the potential of the busbar midpoint of the three-phase inverter system deviates from the potential of the neutral point of the power grid, and the midpoint voltage is not equal to zero. The magnitude of the midpoint voltage when a single-point adhesion fault occurs in the relay group to be tested is different from the magnitude when a two-point adhesion fault occurs in the relay group to be tested. In addition, when adhesion faults occur in different relays in the relay to be tested, the magnitude of the midpoint voltage is also different.

[0080] When the midpoint voltage is equal to the voltage of the first phase, it indicates that the first relay to be tested has a sticking fault; when the midpoint voltage is equal to the voltage of the second phase, it indicates that the second relay to be tested has a sticking fault; when the midpoint voltage is equal to the voltage of the third phase, it indicates that the third relay to be tested has a sticking fault; when the midpoint voltage is equal to half of the negative voltage of the first phase, it indicates that the second relay to be tested and the third relay to be tested have a sticking fault; when the midpoint voltage is equal to half of the negative voltage of the second phase, it indicates that the first relay to be tested and the third relay to be tested have a sticking fault; when the midpoint voltage is equal to half of the negative voltage of the third phase, it indicates that the first relay to be tested and the second relay to be tested have a sticking fault.

[0081] Figure 4 It is a voltage vector diagram provided by an embodiment of the present invention. Take the case where the first relay to be tested and the second relay to be tested in the relay group to be tested have a sticking fault as an example. The midpoint of the three-phase inverter system is point O, the neutral point of the power grid is point N, R is the connection point between the first output phase and the first phase, S is the connection point between the second output phase and the second phase, and T is the connection point between the third output phase and the third phase. Figure 4 , at this time the absolute value of the midpoint voltage satisfies the following equation.

[0082] |V on |=1 / 2×|V Ro |=|V SO ×sin(30°)|=|V TO×sin(30°)|;

[0083] Among them, V on is the midpoint voltage; V Ro is the voltage of the first output phase; V SO is the voltage of the second output phase; V TO is the voltage of the third output phase.

[0084] Reference Figure 4 It can be seen that the midpoint voltage is opposite to the direction of the voltage of the first output phase. Therefore, when the first relay to be tested and the second relay to be tested have a sticking fault, the midpoint voltage is equal to half of the negative third phase voltage.

[0085] Among them, when a adhesion fault occurs in the relay group to be tested, there is AC between the bus midpoint of the three-phase inverter system and the neutral point of the power grid, and the voltage on the power grid side is also AC. At this time, both the midpoint voltage and the power grid voltage use effective values.

[0086] Figure 5 is a flowchart of another relay fault detection method provided by an embodiment of the present invention. Based on the above embodiments, optionally, refer to Figure 5 After determining whether the relay group to be tested has a sticking fault according to the midpoint voltage, the output voltage of each phase of the three-phase inverter system and the voltage of each phase of the power grid, it also includes:

[0087] S140, controlling the relay group to be tested to close and controlling the auxiliary relay group to close.

[0088] Exemplarily, the control module regenerates closing instructions respectively. The first relay group and the second relay group obtain closing instructions, and the first relay group and the second relay group respectively act according to the instructions obtained. At this time, under ideal conditions, the relay group to be tested (the first relay group) and the auxiliary relay group (the second relay group) are both in a closed state. It should be noted that when there are multiple relay groups in the three-phase inverter system, when fault detection is performed on each relay in the three-phase inverter system, there is only one group of relay groups to be tested in the three-phase inverter system, and the rest are auxiliary relay groups.

[0089] S150, reacquiring the output voltage of each phase of the three-phase inverter system and the voltage of each phase of the power grid.

[0090] Specifically, the bus midpoint of the three-phase inverter system can be calculated by the potential of the bus midpoint of the three-phase inverter system (the bus midpoint of the inverter module) and the potential of the neutral point of the power grid. It should be noted that the potential of the bus midpoint of the three-phase inverter system and the potential of the neutral point of the power grid can be obtained by detection or calculation, and the potential of the bus midpoint of the three-phase inverter system and the potential of the neutral point of the power grid can be obtained in a variety of ways. In actual application, different acquisition methods can be selected according to actual needs, and this embodiment does not limit this.

[0091] S160, determining whether the relay group to be tested has a circuit breaker fault according to the re-acquired output voltage of each phase of the three-phase inverter system and the voltage of each phase of the power grid.

[0092] Specifically, under ideal conditions, that is, when no open-circuit fault occurs in each relay in the relay group to be tested, at this time, each phase of the three-phase inverter system is connected to each phase of the power grid in a one-to-one correspondence, and the voltage of each phase of the three-phase inverter system is equal to the voltage of each phase of the power grid, that is, the voltage of the first output phase reacquired is equal to the voltage of the first phase reacquired, the voltage of the second output phase reacquired is equal to the voltage of the second phase reacquired, and the voltage of the third output phase reacquired is equal to the voltage of the third phase reacquired. Therefore, the open-circuit fault detection of each relay in the relay group to be tested can be achieved by comparing the output voltage of each phase of the three-phase inverter system with the voltage of each phase of the power grid.

[0093] Continue to refer to Figure 1 The three-phase inverter system includes two relay groups, the first relay group is used as the relay group to be tested, and the second relay group is used as the auxiliary relay group. The first relay in the first relay group is used as the first relay to be tested, the second relay is used as the second relay to be tested, and the third relay is used as the third relay to be tested; the fourth relay in the second relay group is used as the first auxiliary relay, the fifth relay is used as the second auxiliary relay, and the sixth relay is used as the third auxiliary relay.

[0094] When the voltage of the reacquired first output phase is equal to the voltage of the reacquired first phase, the voltage of the reacquired second output phase is equal to the voltage of the reacquired second phase, and the voltage of the reacquired third output phase is equal to the voltage of the reacquired third phase, it indicates that the relay group to be tested has not had a circuit break fault; when the voltage of the reacquired first output phase is not equal to the voltage of the reacquired first phase, it indicates that a circuit break fault has occurred in the relay between the first output phase and the first phase, and at this time, a short circuit fault has occurred in the first relay to be tested and / or the first auxiliary relay; when the voltage of the reacquired second output phase is not equal to the voltage of the reacquired second phase, it indicates that a circuit break fault has occurred in the relay between the second output phase and the second phase, and at this time, a circuit break fault has occurred in the second relay to be tested and / or the second auxiliary relay; when the voltage of the reacquired third output phase is not equal to the voltage of the reacquired third phase, it indicates that a circuit break fault has occurred in the relay between the third output phase and the third phase, and at this time, a circuit break fault has occurred in the third relay to be tested and / or the third auxiliary relay.

[0095] The embodiment of the present invention further provides a relay fault detection device. The device can be applied to a three-phase inverter system. The device can be implemented by software and / or hardware, and the device can be integrated into a three-phase inverter system. The device can be used to execute the relay fault detection method provided by any embodiment of the present invention, and its technical principle and the effect produced are similar, and will not be repeated.

[0096] The three-phase inverter system includes at least one relay group; the relay group is used to control the connection between the three-phase inverter system and the power grid; each phase of the three-phase inverter system is connected to each phase of the power grid in a one-to-one correspondence.

[0097] Figure 6 Schematic diagram of a relay fault detection device provided by an embodiment of the present invention. Figure 6 The relay fault detection device 100 includes: a relay control module 110 , a collection module 120 and a fault diagnosis module 130 .

[0098] The relay control module 110 is used to control the disconnection of the relay group to be tested in the three-phase inverter system and to control the closing of the auxiliary relay group; wherein, the relay group to be tested is the relay group to be tested in the three-phase inverter system, and the remaining relay groups in the three-phase inverter system except the relay group to be tested are all auxiliary relay groups; the acquisition module 120 is used to obtain the midpoint voltage between the bus midpoint of the three-phase inverter system and the neutral point of the power grid, the output voltage of each phase of the three-phase inverter system and the voltage of each phase of the power grid; the fault diagnosis module 130 is used to determine whether the relay group to be tested has a sticking fault based on the midpoint voltage, the output voltage of each phase of the three-phase inverter system and the voltage of each phase of the power grid.

[0099] Among them, the relay fault detection device 100 provided in the embodiment of the present invention has the beneficial effects of the relay fault detection method provided in any of the above embodiments, which will not be described in detail here.

[0100] Figure 7 : is a schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device may also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0101] like Figure 7 As shown, the electronic device 10 includes at least one processor 11, and a memory connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 to the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0102] A number of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0103] The processor 11 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as a relay fault detection method.

[0104] In some embodiments, the relay fault detection method may be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed on the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the relay fault detection method described above may be performed. Alternatively, in other embodiments, the processor 11 may be configured to perform the relay fault detection method in any other appropriate manner (e.g., by means of firmware).

[0105] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0106] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0107] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in combination with an instruction execution system, device or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0108] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0109] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0110] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0111] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0112] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A relay fault detection method, characterized in that: Applied to a three-phase inverter system, the three-phase inverter system includes at least one relay group; the relay group is used to control the connection between the three-phase inverter system and the power grid; each phase of the three-phase inverter system is connected to each phase of the power grid in a one-to-one correspondence; the relay fault detection method includes: Controlling the relay group to be tested in the three-phase inverter system to be disconnected and controlling the auxiliary relay group to be closed; wherein the relay group to be tested is the relay group to be tested in the three-phase inverter system, and the remaining relay groups in the three-phase inverter system except the relay group to be tested are all auxiliary relay groups; Obtaining a midpoint voltage between a bus midpoint of the three-phase inverter system and a neutral point of a power grid, an output voltage of each phase of the three-phase inverter system, and a voltage of each phase of the power grid; Whether the relay group to be tested has a sticking fault is determined according to the midpoint voltage, the output voltage of each phase of the three-phase inverter system, and the voltage of each phase of the power grid.

2. The relay fault detection method according to claim 1, characterized in that: Each of the relay groups includes three relays; the specific method for determining whether the relay group to be tested has a sticking fault according to the midpoint voltage, the output voltage of each phase of the three-phase inverter system, and the voltage of each phase of the power grid includes: If the midpoint voltage is equal to zero, determining whether a three-point adhesion fault occurs in the relay group to be tested according to the output voltage of each phase of the three-phase inverter system and the voltage of each phase of the power grid; If the midpoint voltage is greater than zero or less than zero, it is determined whether a single-point adhesion fault or a two-point adhesion fault occurs in the relay group to be tested according to the midpoint voltage and the voltages of each phase of the power grid.

3. The relay fault detection method according to claim 2, characterized in that: The three-phase inverter system includes a first output phase, a second output phase and a third output phase; the power grid includes a first phase, a second phase and a third phase; the specific method for determining whether the relay group to be tested has a three-point adhesion fault according to the output voltage of each phase of the three-phase inverter system and the voltage of each phase of the power grid includes: If the output voltage of the first output phase is equal to the voltage of the first phase, the output voltage of the second output phase is equal to the voltage of the second phase, and the output voltage of the third output phase is equal to the voltage of the third phase, then a three-point adhesion fault occurs in the relay group to be tested; If the output voltage of the first output phase is not equal to the voltage of the first phase, the output voltage of the second output phase is not equal to the voltage of the second phase, and the output voltage of the third output phase is not equal to the voltage of the third phase, then the relay group to be tested does not have a sticking fault.

4. The relay fault detection method according to claim 2, characterized in that: The relay group to be tested includes a first relay to be tested, a second relay to be tested and a third relay to be tested; the first relay to be tested is connected between the three-phase inverter system and the first phase of the power grid; the second relay to be tested is connected between the three-phase inverter system and the second phase of the power grid; the third relay to be tested is connected between the three-phase inverter system and the third phase of the power grid; the specific method for determining whether the relay group to be tested has a single-point adhesion fault or a two-point adhesion fault according to the midpoint voltage and the voltages of each phase of the power grid includes: If the midpoint voltage is equal to the voltage of the first phase, a sticking fault occurs in the first relay to be tested; If the midpoint voltage is equal to the voltage of the second phase, a sticking fault occurs in the second relay to be tested; If the midpoint voltage is equal to the voltage of the third phase, a sticking fault occurs in the third relay to be tested; If the midpoint voltage is equal to half of the negative voltage of the first phase, a sticking fault occurs between the second relay to be tested and the third relay to be tested; If the midpoint voltage is equal to half of the negative voltage of the second phase, a sticking fault occurs between the first relay to be tested and the third relay to be tested; If the midpoint voltage is equal to half of the negative voltage of the third phase, a sticking fault occurs between the first relay to be tested and the second relay to be tested.

5. The relay fault detection method according to claim 1, characterized in that: After determining whether the relay group to be tested has a sticking fault according to the midpoint voltage, the output voltage of each phase of the three-phase inverter system, and the voltage of each phase of the power grid, the method further includes: Controlling the relay group to be tested to close and controlling the auxiliary relay group to close; Re-obtaining the output voltage of each phase of the three-phase inverter system and the voltage of each phase of the power grid; Whether the relay group to be tested has a circuit breaker fault is determined based on the re-acquired output voltage of each phase of the three-phase inverter system and the voltage of each phase of the power grid.

6. The relay fault detection method according to claim 5, characterized in that: The first output phase of the three-phase inverter system is connected to the first phase of the power grid; the second output phase of the three-phase inverter system is connected to the second phase of the power grid; the third output phase of the three-phase inverter system is connected to the third phase of the power grid; the specific method of determining whether the relay group to be tested has a circuit breaker fault according to the output voltage of each phase of the three-phase inverter system and the voltage of each phase of the power grid includes: If the voltage of the first output phase reacquired is equal to the voltage of the first phase reacquired, the voltage of the second output phase reacquired is equal to the voltage of the second phase reacquired, and the voltage of the third output phase reacquired is equal to the voltage of the third phase reacquired, then the relay group to be tested does not have a circuit breaker fault; If the re-acquired voltage of the first output phase is not equal to the re-acquired voltage of the first phase, a circuit breaker fault occurs in the relay between the first output phase and the first phase; If the reacquired voltage of the second output phase is not equal to the reacquired voltage of the second phase, a circuit breaker fault occurs in the relay between the second output phase and the second phase; If the re-acquired voltage of the third output phase is not equal to the re-acquired voltage of the third phase, a circuit breaker fault occurs in the relay between the third output phase and the third phase.

7. The relay fault detection method according to claim 1, characterized in that: The specific method for obtaining the midpoint voltage includes: Acquiring the potential of the bus midpoint of the three-phase inverter system and the potential of the neutral point of the power grid; The midpoint voltage is calculated according to the potential of the bus midpoint of the three-phase inverter system and the potential of the neutral point of the power grid.

8. A relay fault detection device, characterized in that: Applied to a three-phase inverter system, the three-phase inverter system includes at least one relay group; the relay group is used to control the connection between the three-phase inverter system and the power grid; each phase of the three-phase inverter system is connected to each phase of the power grid in a one-to-one correspondence; the relay fault detection device includes: A relay control module, used for controlling the disconnection of the relay group to be tested in the three-phase inverter system and controlling the closing of the auxiliary relay group; wherein the relay group to be tested is the relay group to be tested in the three-phase inverter system, and the remaining relay groups in the three-phase inverter system except the relay group to be tested are all auxiliary relay groups; An acquisition module, used to obtain the midpoint voltage between the bus midpoint of the three-phase inverter system and the neutral point of the power grid, the output voltage of each phase of the three-phase inverter system, and the voltage of each phase of the power grid; A fault diagnosis module is used to determine whether the relay group to be tested has a sticking fault according to the midpoint voltage, the output voltage of each phase of the three-phase inverter system and the voltage of each phase of the power grid.

9. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the relay fault detection method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the relay fault detection method according to any one of claims 1 to 7 when executed.

Images