Wiring detection method and device, electric energy conversion device and electric energy conversion system

Abstract

This application discloses a wiring detection method, apparatus, power conversion device, and power conversion system, belonging to the field of power electronics. The wiring detection method is applied to a power conversion system, which includes at least one power conversion device and multiple grid ports for connection to the power grid and multiple load ports for connection to loads. The method includes: acquiring the phase voltage corresponding to a target port while controlling each power conversion device to be in its corresponding operating state; the target port is at least one of the multiple grid ports and multiple load ports, and the target port is determined based on the detection target and the circuit structure of the power conversion system; and determining the wiring state corresponding to the detection target based on the phase voltage. This wiring detection method reduces redundant sampling and unnecessary detection of irrelevant ports by selectively selecting corresponding voltage sampling ports, thereby reducing the difficulty of wiring fault diagnosis and location.

Description

Technical Field

[0001] This application belongs to the field of power electronics, and in particular relates to a wiring detection method, device, power conversion equipment, and power conversion system. Background Technology

[0002] In related technologies, power conversion systems typically incorporate one or more power conversion devices to achieve connection and switching between the power grid and the load. Because power conversion devices usually have both grid and load ports, and involve single-phase or multi-phase conductor connections, the on-site wiring process is complex and prone to problems such as mixed connections, omissions, and incorrect connections. When multiple power conversion devices are operating in parallel, inconsistencies in the phase correspondence of the ports can lead to abnormal phase sequence, potentially causing phase-to-phase short circuits and other fault risks, making on-site troubleshooting and location difficult. Summary of the Invention

[0003] This application aims to address at least one of the technical problems existing in the prior art. To this end, this application proposes a wiring detection method, device, power conversion equipment, and power conversion system. By selectively selecting corresponding voltage sampling ports, redundant sampling and unnecessary detection of irrelevant ports are reduced, thereby lowering the difficulty of wiring fault diagnosis and location.

[0004] In a first aspect, this application provides a wiring detection method applied to a power conversion system, the power conversion system including at least one power conversion device, the power conversion system including multiple grid ports for connection to the power grid and multiple load ports for connection to a load; the method includes: While controlling each power conversion device to be in its corresponding working state, the phase voltage corresponding to the target port is obtained; the target port is at least one of the plurality of grid ports and the plurality of load ports, and the target port is determined based on the detection target and the circuit structure of the power conversion system; Based on the phase voltage, the wiring status corresponding to the detection target is determined.

[0005] According to the wiring detection method of this application, by acquiring the phase voltage of the target port while controlling each power conversion device to be in the corresponding working state, the electrical interference of internal unrelated circuits is reduced, so that the collected voltage data can truly reflect the external physical wiring situation. At the same time, the target port is determined based on the detection target and the circuit structure of the power conversion system. According to the specific fault type to be investigated and the single / parallel architecture, the corresponding voltage sampling port can be selectively selected, reducing redundant sampling and unnecessary detection of irrelevant ports, thereby reducing the difficulty of wiring fault investigation and location.

[0006] According to one embodiment of this application, when the circuit structure is a single power conversion device, the phase voltage of the grid port or load port is obtained based on a first detection target; the first detection target includes: missing wiring, incorrect wiring, or mixed wiring. In the case where the circuit structure consists of multiple power conversion devices, the phase voltage of the load port or the phase voltage of the load port and the phase voltage of the grid port are obtained based on the second detection target; the second detection target includes: missing wiring, incorrect wiring, or phase sequence consistency status.

[0007] According to one embodiment of this application, in the case where the circuit structure is a single power conversion device, obtaining the phase voltage of the grid port or load port based on a first detection target includes: When the first detection target is a mixed wiring, the phase voltage of each phase of the load port is determined as the phase voltage corresponding to the target port; If the first detection target is a missing or incorrect wiring connection, the phase voltage of each phase of the power grid port is determined as the phase voltage corresponding to the target port.

[0008] According to one embodiment of this application, determining the wiring state corresponding to the detection target based on the phase voltage includes: If the first detection target is a missing connection and the phase voltage is less than or equal to a first voltage threshold, it is determined that the missing connection exists at the power grid port corresponding to the phase voltage. If the first detection target is a wiring misconnection, and the difference between the phase voltage of one phase and the grid phase voltage is less than or equal to a second voltage threshold, and the difference between the phase voltage of the remaining phases and the grid line voltage is less than or equal to a third voltage threshold, then it is determined that the grid port corresponding to the phase voltage whose difference from the grid phase voltage is less than or equal to the second voltage threshold has the wiring misconnection. If the first detection target is a mixed wiring connection, and the phase voltage is less than or equal to the fourth voltage threshold, it is determined that there is no mixed wiring connection between the load port and the grid port corresponding to the phase voltage.

[0009] According to one embodiment of this application, when the circuit structure comprises multiple power conversion devices, obtaining the phase voltage of the load port or the phase voltage of the load port and the phase voltage of the grid port based on the second detection target includes: When the second detection target is a missing or incorrect wiring connection, the phase voltage of each phase of the load port is determined as the phase voltage corresponding to the target port. When the second detection target is in a phase sequence consistency state, the phase voltage of each phase of the grid port and the phase voltage of each phase of the load port are determined as the phase voltage corresponding to the target port.

[0010] According to one embodiment of this application, determining the wiring state corresponding to the detection target based on the phase voltage includes: If the second detection target is a missing connection and the phase voltage is less than or equal to the fifth voltage threshold, it is determined that the missing connection exists at the load port corresponding to the phase voltage. If the second detection target is a wiring misconnection, and the difference between the phase voltage of one phase and the grid phase voltage is less than or equal to the sixth voltage threshold, and the difference between the phase voltage of the remaining phases and the grid line voltage is less than or equal to the seventh voltage threshold, then it is determined that the load port corresponding to the phase voltage whose difference between the phase voltage and the grid phase voltage is less than or equal to the sixth voltage threshold has the wiring misconnection.

[0011] According to one embodiment of this application, determining the wiring state corresponding to the detection target based on the phase voltage includes: When the second detection target is a phase sequence consistency state, based on the phase voltage of each phase of the grid port and the phase voltage of each phase of the load port, the number of phases whose difference between the phase voltage difference and the grid line voltage is less than or equal to the eighth voltage threshold is obtained. When the number of phases is a first quantity, it is determined that the phase sequence between the power grid port and the load port is consistent; If the number of phases is not a first number, it is determined that the phase sequence between the power grid port and the load port is inconsistent.

[0012] According to one embodiment of this application, after determining that the phase sequence between the power grid port and the load port is inconsistent, the method further includes: Based on the number of phases, determine the number of times the phase sequence of the power grid port and the load port is inconsistent.

[0013] According to one embodiment of this application, determining the number of times the phase sequence of the grid port and the load port is inconsistent based on the number of phases includes: When the number of phases is the second quantity, it is determined that the phase sequence of the second quantity of phases at the power grid port and the load port is inconsistent; When the number of phases is the third number, it is determined that the phase sequence of the third number of phases at the power grid port and the load port is inconsistent; If the number of phases is greater than a third number, it is determined that the phase sequence of the third or more phases at the power grid port and the load port is inconsistent.

[0014] According to one embodiment of this application, obtaining the phase voltage corresponding to the target port while controlling each power conversion device to be in its corresponding operating state includes: In the case where the circuit structure is a single power conversion device, the electrical connection between the grid port and the load port of the power conversion device is disconnected. In the case where the circuit structure comprises multiple power conversion devices, an electrical connection is established between the grid port and the load port of the target power conversion device to bring the grid voltage to the load port, and the electrical connection between the grid port and the load port of all other power conversion devices except the target power conversion device is disconnected; wherein, the target power conversion device is any one of the multiple power conversion devices.

[0015] Secondly, this application provides a wiring detection device applied to a power conversion system, the power conversion system including at least one power conversion device, the power conversion system including a plurality of grid ports for connection to the power grid and a plurality of load ports for connection to a load, the device including: The first processing module is used to acquire the phase voltage corresponding to the target port while controlling each power conversion device to be in the corresponding working state; the target port is at least one of the plurality of grid ports and the plurality of load ports, and the target port is determined based on the detection target and the circuit structure of the power conversion system. The second processing module is used to determine the wiring status corresponding to the detection target based on the phase voltage.

[0016] According to the wiring detection device of this application, by controlling each power conversion device to be in the corresponding working state, the phase voltage of the target port is obtained, which reduces the electrical interference of internal unrelated circuits, so that the collected voltage data can truly reflect the external physical wiring situation. At the same time, the target port is determined based on the detection target and the circuit structure of the power conversion system. According to the specific fault type to be investigated and the single / parallel architecture, the corresponding voltage sampling port can be selectively screened, reducing redundant sampling and unnecessary detection of irrelevant ports, thereby reducing the difficulty of wiring fault investigation and location.

[0017] Thirdly, this application provides a power conversion device, comprising: Multiple terminals, including: a power grid terminal connected to a power grid port and a load terminal connected to a load port; The power conversion equipment detects the wiring status based on the wiring detection method described in the first aspect above.

[0018] According to one embodiment of this application, the power conversion device includes: Multiple switches are used to connect the load terminals and the corresponding power grid terminals.

[0019] Fourthly, this application provides a power conversion system, comprising: At least one power conversion device, the power conversion system comprising a plurality of grid ports for connection to the power grid and a plurality of load ports for connection to loads; The power conversion system detects the wiring status based on the wiring detection method described in the first aspect above.

[0020] According to one embodiment of this application, when the power conversion system includes multiple power conversion devices, the grid port of each power conversion device is connected in parallel to the power grid, and the load port of each power conversion device is connected in parallel to the load.

[0021] Fifthly, this application provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the wiring detection method as described in the first aspect above.

[0022] In a sixth aspect, this application provides a computer program product, including a computer program that, when executed by a processor, implements the wiring detection method as described in the first aspect above.

[0023] The above-described one or more technical solutions in the embodiments of this application have at least one of the following technical effects: By acquiring the phase voltage of the target port while controlling each power conversion device to be in its corresponding working state, electrical interference from unrelated internal circuits is reduced, ensuring that the collected voltage data accurately reflects the external physical wiring conditions. Simultaneously, by determining the target port based on the detection target and the circuit structure of the power conversion system, the corresponding voltage sampling port can be selectively chosen according to the specific fault type to be investigated and the single / parallel architecture. This reduces redundant sampling and unnecessary detection of irrelevant ports, thereby lowering the difficulty of troubleshooting and locating wiring faults.

[0024] Furthermore, in the case of a single power conversion device in the circuit structure, the phase voltage of the load port or grid port is obtained respectively for the fault categories of mixed wiring, missing wiring, and incorrect wiring in the detection target. By utilizing the voltage characteristics corresponding to different wiring topologies when the internal switch of the device is opened, the port or phase of the wiring abnormality can be determined. This helps to conduct targeted investigation of specific fault nodes, thereby reducing the difficulty of wiring fault investigation and location, and improving the efficiency of wiring fault investigation and location.

[0025] Furthermore, in the case of multiple power conversion devices in the circuit structure, corresponding to the missing wiring, incorrect wiring, and phase sequence consistency status in the detection target, under the premise that the switch of the target power conversion device is turned on and the switches of other power conversion devices are turned off, the phase voltage of the load port of the power conversion device under test, or the phase voltage of the grid port and the load port, are obtained respectively. Furthermore, combined with the specific voltage characteristics of the power conversion device under test under different wiring topologies, the port or phase of the wiring abnormality is determined, which helps to conduct targeted investigation of specific fault nodes, thereby reducing the difficulty of wiring fault investigation and location, and improving the efficiency of wiring fault investigation and location.

[0026] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0027] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is one of the flowcharts illustrating the wiring detection method provided in the embodiments of this application; Figure 2 This is one of the structural schematic diagrams of the power conversion system provided in the embodiments of this application; Figure 3 This is a second schematic diagram of the power conversion system provided in the embodiments of this application; Figure 4 This is the third schematic diagram of the power conversion system provided in the embodiments of this application; Figure 5 This is a second schematic flowchart of the wiring detection method provided in the embodiments of this application; Figure 6 This is the fourth schematic diagram of the power conversion system provided in the embodiments of this application; Figure 7 This is a voltage sampling phasor diagram provided in the embodiments of this application under the condition of incorrect grid port connection; Figure 8 This is the third flowchart illustrating the wiring detection method provided in the embodiments of this application; Figure 9 This is the fifth schematic diagram of the power conversion system provided in the embodiments of this application; Figure 10 This is the fourth flowchart illustrating the wiring detection method provided in the embodiments of this application; Figure 11 This is the sixth schematic diagram of the power conversion system provided in the embodiments of this application; Figure 12This is the seventh schematic diagram of the power conversion system provided in the embodiments of this application; Figure 13 This is the eighth schematic diagram of the power conversion system provided in the embodiments of this application; Figure 14 This is the fifth flowchart illustrating the wiring detection method provided in the embodiments of this application; Figure 15 This is the ninth schematic diagram of the power conversion system provided in the embodiments of this application; Figure 16 This is the tenth flowchart illustrating the wiring detection method provided in the embodiments of this application; Figure 17 This is eleventh of the structural schematic diagrams of the power conversion system provided in the embodiments of this application; Figure 18 This is the twelfth schematic diagram of the power conversion system provided in the embodiments of this application; Figure 19 This is the thirteenth schematic diagram of the power conversion system provided in the embodiments of this application; Figure 20 This is eleventh of the flowcharts illustrating the wiring detection method provided in the embodiments of this application; Figure 21 This is the fourteenth schematic diagram of the power conversion system provided in the embodiments of this application; Figure 22 This is the fifteenth schematic diagram of the power conversion system provided in the embodiments of this application; Figure 23 This is a schematic diagram of the wiring detection device provided in the embodiments of this application; Figure 24 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0028] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0029] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0030] The wiring detection method, wiring detection device, power conversion equipment, and power conversion system provided in this application will be described in detail below with reference to the accompanying drawings and through specific embodiments and application scenarios.

[0031] The wiring detection method can be applied to the terminal, and can be executed by the hardware or software in the terminal.

[0032] The wiring detection method provided in this application embodiment can be executed by a power conversion system or a functional module or entity within the power conversion system that can implement the wiring detection method. The wiring detection method provided in this application embodiment is described below using a power conversion system as the executing entity.

[0033] During the research and development process, the inventors discovered that in the process of connecting and interacting between the power grid and the load based on one or more power conversion devices, in scenarios with a power grid, the simultaneous presence of grid-connected and off-grid (load-load) ports on a single power conversion device leads to complex wiring, which can easily result in problems such as mixed connections, missing connections, and incorrect connections of individual devices, and makes on-site troubleshooting of wiring difficult. In addition, in scenarios with a power grid, the wiring is more complex when multiple power conversion devices are connected in parallel, which can easily result in problems such as abnormal phase sequence between multiple power conversion devices leading to phase-to-phase short circuit faults, and makes on-site troubleshooting of wiring difficult.

[0034] To address the challenge of detecting and locating wiring faults, the inventors, through in-depth research, designed a wiring detection method. This method includes: acquiring the phase voltage corresponding to the target port while controlling each power conversion device to operate in its corresponding state; the target port is at least one of multiple grid ports and multiple load ports, and the target port is determined based on the detection target and the circuit structure of the power conversion system; and determining the wiring state corresponding to the detection target based on the phase voltage.

[0035] According to the wiring detection method provided in this application embodiment, by acquiring the phase voltage of the target port while controlling each power conversion device to be in the corresponding working state, the electrical interference of internal unrelated circuits is reduced, so that the collected voltage data can truly reflect the external physical wiring situation; at the same time, the target port is determined based on the detection target and the circuit structure of the power conversion system, and the corresponding voltage sampling port can be selectively selected according to the specific fault type to be investigated and the single / parallel architecture, reducing redundant sampling and unnecessary detection of irrelevant ports, thereby reducing the difficulty of wiring fault investigation and location.

[0036] The wiring detection method of this application is applied to a power conversion system. The power conversion system includes at least one power conversion device, and includes multiple grid ports for connection to the power grid and multiple load ports for connection to loads. It should be noted that this wiring detection method can be applied to grid-connected scenarios.

[0037] In some embodiments, the wiring detection method can be applied to power supply systems with different phase line configurations, such as single-phase, three-phase, or multi-phase systems.

[0038] To clearly illustrate the technical solution of this application, the following description will use specific applications of grid-connected scenarios (i.e., scenarios with power grids) combined with three-phase AC systems as examples.

[0039] In some embodiments, the power conversion equipment may include, but is not limited to, an inverter and a grid-connected / off-grid switching device (also known as a gateway module), which are not specifically limited herein; wherein, the grid-connected / off-grid switching device may be located outside or inside the inverter or used as an independent device in conjunction with the inverter.

[0040] In some embodiments, the off-grid switching device has multiple switching units inside. Each switching unit contains at least one switching device.

[0041] In this embodiment, the switching device can be a relay, a contactor, a semiconductor switch, or a combination thereof, etc., and this application does not specifically limit it. For ease of description, a relay will be used as a specific example of the switching device in the following description.

[0042] In actual implementation, taking a three-phase power supply system as an example, such as Figure 2The circuit structure shown includes a single power conversion device with eight terminals, which are connected to four grid ports for connection to the power grid and four load ports for connection to the load. The grid ports include grid phase ports (i.e., grid A-phase, B-phase, and C-phase ports) and grid neutral ports (i.e., grid N-line ports) for connection to the corresponding phases of the power grid. The load ports include load phase ports (i.e., load A-phase, B-phase, and C-phase ports) and load neutral ports (i.e., load N-line ports) for connection to the corresponding loads.

[0043] It should be understood that in power supply systems with other phase line configurations, the number and correspondence of the above ports can be adjusted accordingly, and this application does not impose specific restrictions on this.

[0044] Continue to refer to Figure 2 The power conversion equipment includes a grid-connected / off-grid switching device (Gateway, GW) installed inside the inverter. For ease of description, the grid-connected / off-grid switching device installed inside the inverter will be referred to as the built-in GW in the following description.

[0045] The built-in GW contains four sets of switching units: Relay_1, Relay_2, Relay_3, and Relay_4. These sets of switching units are connected in series between the corresponding grid port and load port, and can be engaged or disengaged based on control commands.

[0046] Continue to refer to Figure 2 To enable wiring detection, voltage sampling circuits are installed on both the grid port side and the load port side of each phase. Taking phase A branch as an example, Figure 2 The specific connection methods of each component are as follows: Voltage sampling points near the grid side are connected between each phase grid port (e.g., A phase Grid_Port) and the corresponding switching unit (e.g., Relay_1) to obtain the phase voltage of each phase grid port; The voltage sampling circuit near the load side is connected between the corresponding switching unit (such as Relay_1) and each phase load port (such as phase A Load_Port). The sampling point can be led out through the resistor to obtain the phase voltage of each phase load port.

[0047] In other practical implementations, taking a three-phase power supply system as an example, such as... Figure 11 The circuit structure shown includes multiple power conversion devices connected in parallel, and correspondingly, multiple built-in power generators.

[0048] It should be noted that this application does not specifically limit the connection location of the aforementioned voltage sampling points and voltage sampling circuits. Any location that can achieve the acquisition of phase voltages at each phase of the power grid port and each phase of the load port is acceptable and is protected by this application. (Continue to refer to...) Figure 11 Each built-in GW's grid port (Grid_Port) is connected in parallel to the corresponding phase line of the power grid; each built-in GW's load port (Load_Port) is also connected in parallel to the corresponding phase line of the load. The circuit topology, terminal definitions, and voltage sampling circuit connection methods within each built-in GW are as described above. Figure 2 The embodiments of the single power conversion device shown are consistent and will not be repeated here.

[0049] It should be noted that the specific number and physical topology of the relays contained in each switching unit are not limited in the embodiments of this application.

[0050] In actual implementation, an inverter topology with a built-in GW is as follows: Figure 21 As shown.

[0051] In this topology, the power conversion equipment includes an inverter module (Inv), a built-in GW (Gateway), grid ports (Grid_Port) for connecting to the A, B, C, and N lines of the power grid, and load ports (Load_Port) for connecting to the A, B, C, and N lines of the load. The inverter module (Inv) is connected to the internal bus via relays S_1x (x=A, B, C, N).

[0052] Continue to refer to Figure 21 Each phase of the built-in GW is equipped with two relays, S_2x and S_3x (x=A, B, C, N). The grid port is connected to the internal bus through relay S_2x, and the load port is connected to the internal bus through relay S_3x. S_2x and S_3x together constitute a set of relays used to control the connection status of the connection.

[0053] In actual implementation, inverter topologies with built-in GW can also be used as follows: Figure 22 As shown.

[0054] This topology also includes an inverter module (Inv), an internal GW (Gateway), a grid port (Grid_Port), and a load port (Load_Port).

[0055] For phases A, B, and C, each phase is equipped with two relays, S_2x and S_3x (x=A, B, C), which together form a set of relays; while for phase N, a relay S_2N is configured on the grid port side, which forms a separate set of relays.

[0056] like Figure 1 As shown, the wiring detection method includes steps 110 and 120.

[0057] Step 110: Under the condition that each power conversion device is in the corresponding working state, obtain the phase voltage corresponding to the target port; In this step, the target port is at least one of multiple power grid ports and multiple load ports.

[0058] The target port is determined based on the detection target and the circuit structure of the power conversion system.

[0059] In some embodiments, step 110 includes: In the case of a single power conversion device in a circuit structure, the phase voltage of the grid port or load port is obtained based on the first detection target; In the case of a circuit structure consisting of multiple power conversion devices, the phase voltage of the load port or the phase voltage of the load port and the phase voltage of the grid port are obtained based on the second detection target.

[0060] In this step, the first detection targets include: missing wiring, incorrect wiring, or mixed wiring.

[0061] The second detection target includes: missing wiring, incorrect wiring, or phase sequence inconsistency.

[0062] In some embodiments, step 110 includes: In the case of a single power conversion device in a circuit structure, the electrical connection between the grid port and the load port of the power conversion device is disconnected. In the case of a circuit structure consisting of multiple power conversion devices, the system controls the establishment of an electrical connection between the grid port and the load port of the target power conversion device to bring the grid voltage to the load port, and controls the disconnection of the electrical connection between the grid port and the load port of all other power conversion devices except the target power conversion device.

[0063] In this embodiment, the target power conversion device is any one of a plurality of power conversion devices, such as a host power conversion device that serves as the master device; the remaining power conversion devices other than the host power conversion device are slave power conversion devices.

[0064] In actual operation, when the circuit structure is a single power conversion device, all the switching units inside the power conversion device are in the open state. In this operating state, the phase voltage of the grid port or the phase voltage of the load port is obtained.

[0065] Based on the phase voltage of the obtained power grid port or load port, the following wiring tests can be performed: (1) the wiring of the power grid port and the load port is mixed; (2) the wiring of the power grid port is incorrect; (3) the wiring of the power grid port is missing.

[0066] In other actual implementation processes, such as Figure 12 As shown, in the case where the circuit structure consists of multiple power conversion devices connected in parallel, each power conversion device is equipped with a built-in GW.

[0067] Continue to refer to Figure 12 From multiple power conversion devices, any one device can be selected as the target power conversion device. For example, the power conversion device that serves as the master device can be selected as the target power conversion device, and the remaining power conversion devices can be used as slave devices. The following explanation will use this as an example. The relays in each group of switching units (i.e., Relay_1 to Relay_4) inside the master device are energized, and the relays in the switching units inside the slave devices other than the master device are de-energized. At this time, the power grid is connected to the load port through the relays of the master device.

[0068] Continue to refer to Figure 12 Since the load ports of all power conversion devices are connected in parallel, the load ports of each power conversion device (including the master and each slave) can sense and collect the grid voltage guided by the master.

[0069] By sampling the three-phase voltage at the load port (x=A, B, C) or obtain the grid-load voltage difference. (x=A, B, C), the following wiring tests can be performed: (1) incorrect wiring of the load port; (2) missing wiring of the load port; (3) phase sequence consistency of the load port and the power grid port.

[0070] Understandable Figure 12 This example uses only one master and one slave, but in real-world applications, the number of slaves can be flexibly set, and this application does not limit this.

[0071] It should be noted that the above-mentioned phase voltage sampling method can be achieved through the voltage sampling circuit set in the power conversion equipment itself, or through external sensor sampling and other methods.

[0072] In some embodiments, when the circuit structure is a single power conversion device, obtaining the phase voltage of the grid port or load port based on a first detection target includes: When the first detection target is a mixed wiring, the phase voltage of each phase of the load port is determined as the phase voltage corresponding to the target port. When the first detection target is a missing or incorrect wiring connection, the phase voltage of each phase at the grid port is determined as the phase voltage corresponding to the target port.

[0073] In this embodiment, the first detection target refers to the wiring abnormality detection task performed on a single power conversion device, which specifically corresponds to different wiring fault types.

[0074] The following is a detailed description of a circuit structure consisting of a single power conversion device, with the primary detection target being a misconnected wire.

[0075] In practice, wiring misconnection detection refers to detecting whether there is a misconnection between the power grid port and the load port. Specific scenarios include: the power grid line being incorrectly connected to the load port, or the load line being incorrectly connected to the power grid port.

[0076] To achieve the above-mentioned wiring misconnection detection, it is necessary to disconnect the electrical connection between the grid port and the load port of the power conversion equipment (i.e., the internal relays of the power conversion equipment must be in the off state). Since the first detection target is wiring misconnection, the phase voltage corresponding to the target port is the phase voltage of each phase of the load port.

[0077] In such Figure 3 In the scenario depicting a single-phase misconnection between the grid port and the load port, the A-phase power supply line of the grid is incorrectly connected to the A-phase load port (Load_Port) of the device, while the A-phase line of the load is incorrectly connected to the A-phase grid port (Grid_Port) of the device; at this time, the B-phase, C-phase, and N-phase connections of the grid and the load are normal. Under this single-phase misconnection condition, because the grid is always energized, even if the internal relay of the device is disconnected, the A-phase load port of the power conversion device will still collect the voltage input from the grid.

[0078] It is understandable that the detection results of the load ports of phase B, phase C, and line N are consistent with the detection results of the load port of phase A mentioned above, and will not be repeated here.

[0079] exist Figure 4 In the scenario shown, where the grid port and load port are connected in a three-phase mixed manner, the A-phase, B-phase, C-phase, and N-phase lines of the grid are incorrectly connected to the corresponding load port (Load_Port) of the device, while the A-phase, B-phase, C-phase, and N-phase lines of the load are incorrectly connected to the corresponding grid port (Grid_Port) of the device. Under this three-phase mixed connection condition, since the grid is always energized, even if the internal relay of the device is disconnected, the A-phase, B-phase, and C-phase load ports of the power conversion device will abnormally collect the grid voltage of the corresponding phase.

[0080] By detecting whether the phase voltage corresponding to each load port is greater than the set voltage threshold (i.e., it is in a energized state), it can be determined whether there is a wiring misconnection between the grid port and the load port, and the specific phase where the misconnection occurred can be located based on the specific phase port of the collected voltage.

[0081] The following is a detailed description of a circuit structure consisting of a single power conversion device, where the primary detection target is incorrect wiring.

[0082] In practice, wiring misconnection detection refers to detecting whether the live wire (i.e., the aforementioned A-phase, B-phase, or C-phase wires) and the neutral wire (i.e., the aforementioned N-wire) are incorrectly connected at the power grid port. Specific examples include: a phase wire of the power grid is incorrectly connected to the N-wire terminal of the equipment's power grid port, while the N-wire of the power grid is incorrectly connected to the phase wire terminal of the equipment's power grid port.

[0083] To achieve the aforementioned wiring misconnection detection, it is necessary to disconnect the electrical connection between the grid port and the load port of the power conversion equipment. Since the primary detection target is wiring misconnection, the phase voltage corresponding to the target port is the phase voltage of each phase of the grid port.

[0084] In such Figure 6 In the scenario shown, where phase A and phase N of the power grid are incorrectly connected (referred to as AN incorrect connection), the A-phase power supply line of the power grid is incorrectly connected to the N-phase power grid port of the device, while the N-phase power grid line is incorrectly connected to the A-phase power grid port of the device; at this time, the B-phase and C-phase connections of the power grid are normal.

[0085] Combination Figure 7 As shown in the phasor diagram of grid voltage sampling when the grid port AN is misconnected, when the live wire and neutral wire of the grid port are misconnected, the phase voltage of the misconnected phase is sampled as the grid phase voltage, which is the rated phase voltage of the grid. The phase voltages of the other two phases are sampled as the grid line voltage, which is the rated line voltage of the grid.

[0086] By comparing the voltage amplitude characteristics collected from each phase of the power grid port, it is possible to determine whether there is a wiring error at the power grid port, and the specific phase where the error occurred can be located based on the voltage amplitude characteristics collected from each phase.

[0087] The following is a detailed explanation of a circuit structure consisting of a single power conversion device, with the primary detection target being a missing connection.

[0088] In practice, wire connection omission detection refers to detecting whether there is an omission in the live wire (i.e., the aforementioned A-phase, B-phase, or C-phase wire) at the power grid port. Specific examples include situations where one or more phases of the power grid supply line are not connected to the corresponding power grid port of the equipment (i.e., they are physically suspended or disconnected).

[0089] To achieve the aforementioned wire connection leakage detection, it is necessary to disconnect the electrical connection between the grid port and the load port of the power conversion equipment. Since the primary detection target is a wire connection leakage, the phase voltage corresponding to the target port is the phase voltage of each phase of the grid port.

[0090] In such Figure 9 In the scenario shown where phase A of the power grid port is missing, phases B, C, and N of the power grid are all normally connected to their respective power grid ports, while the power supply line for phase A is not connected to the A-phase power grid port of the device. Under this condition, because the internal relay of the device is in the open state and phase A is not connected, the A-phase power grid port of the power conversion device will not be able to collect the voltage of the power grid (i.e., the sampling voltage of phase A is zero or close to zero), while the B-phase and C-phase power grid ports can normally collect the corresponding phase voltages of the power grid.

[0091] By determining whether there is an abnormally low phase voltage (e.g., the voltage amplitude is less than or equal to the set low voltage threshold) in one or more phases of each power grid port, it can be determined whether there is a missing connection in the power grid port, and the specific phase where the missing connection occurred can be located based on the specific port where normal voltage was not collected.

[0092] According to the wiring detection method provided in the embodiments of this application, when the circuit structure is a single power conversion device, the phase voltage of the load port or the grid port is obtained respectively for the fault categories of mixed wiring, missing wiring and incorrect wiring in the detection target. By using the voltage characteristics corresponding to different wiring topologies when the internal switch of the device is opened, the port or phase of the wiring abnormality is determined. This helps to conduct targeted investigation of specific fault nodes, thereby reducing the difficulty of wiring fault investigation and location, and improving the efficiency of wiring fault investigation and location.

[0093] In some embodiments, when the circuit structure comprises multiple power conversion devices, obtaining the phase voltage of the load port or the phase voltage of the load port and the phase voltage of the grid port based on the second detection target includes: When the second detection target is a missing or incorrect wiring connection, the phase voltage of each phase of the load port is determined as the phase voltage corresponding to the target port. When the second detection target is the phase sequence consistency state, the phase voltage of each phase of the grid port and the phase voltage of each phase of the load port are determined as the phase voltage corresponding to the target port.

[0094] In this embodiment, the second detection target refers to the wiring anomaly detection task performed on multiple power conversion devices, which specifically corresponds to different wiring fault types.

[0095] The following is a detailed description of a circuit structure consisting of multiple power conversion devices, where the second detection target is incorrect wiring.

[0096] In practice, wiring misconnection detection refers to detecting whether the live wire (i.e., the aforementioned A-phase, B-phase, or C-phase wire) and the neutral wire (i.e., the aforementioned N-line) are incorrectly connected at the load port. The specific situation is similar to the aforementioned power grid port misconnection detection, and will not be repeated here to avoid repetition.

[0097] To achieve the above detection, it is necessary to control the relay in the main power conversion device (i.e., the main unit) to engage, so as to lead the grid voltage to the load port, and control the relays between the grid port and the load port of the remaining slave power conversion devices (i.e., the slaves) to disconnect. Since the second detection target is a wiring misconnection, the phase voltage corresponding to the target port is the phase voltage of each phase of the load port.

[0098] In such Figure 13 In the scenario shown, where the load port A phase and N phase are incorrectly connected (referred to as AN incorrect connection), the load's A phase line is incorrectly connected to the load N line port of one of the slave devices, while the load's N line is incorrectly connected to the load A phase port of that slave device; at this time, the wiring of the slave device's load B phase and C phase, as well as the wiring of other devices, are all normal.

[0099] Consistent with the aforementioned principle of detecting incorrect wiring at the power grid port, since the reference zero potential for voltage sampling inside the slave device has actually become the A-phase potential of the load, when the slave device obtains the phase voltage of its load port, the phase voltage sampling amplitude of the incorrectly connected phase still represents the power grid phase voltage, such as the rated phase voltage of the power grid, while the phase voltage sampling amplitude of the other two correctly connected phases represents the power grid line voltage, such as the rated line voltage of the power grid.

[0100] By judging the voltage amplitude characteristics collected from the load port, it is possible to determine whether there is a wiring error at the load port, and the specific phase where the error occurred can be located based on the collected voltage amplitude characteristics.

[0101] The following is a detailed explanation of a circuit structure consisting of multiple power conversion devices, with the second detection target being a missing connection.

[0102] In practice, wiring leak detection refers to detecting whether there is a missing connection of the live wire (i.e., the aforementioned A-phase, B-phase, or C-phase wire) at the load port. The specific situation is similar to that of the aforementioned power grid port leak detection, and will not be repeated here to avoid repetition.

[0103] To achieve the above detection, it is necessary to control the relays in the main power conversion device to engage, thereby bringing the grid voltage to the load port, and to control the relays in the other slave power conversion devices to disconnect between the grid port and the load port. Since the second detection target is a missing connection, the phase voltage corresponding to the target port is the phase voltage of each phase of the load port.

[0104] In such Figure 15In the scenario shown where load port A phase is missing, the load's B phase, C phase, and N line are all normally connected to the corresponding load ports of each power conversion device, but the load's A phase line is not connected to the A phase load port of one of the slave devices.

[0105] Consistent with the aforementioned principle of detecting missing connections at the power grid ports, under this condition, since the relay of the slave unit is in the off state and phase A is not connected, the phase A load port will not be able to collect the load voltage, that is, it will not be able to collect the power grid voltage, while the phase B and phase C load ports can normally collect the corresponding power grid phase voltages.

[0106] By determining whether there is an abnormally low phase voltage in one or more phases of each load port (e.g., the voltage amplitude is less than or equal to the set low voltage threshold), it can be determined whether there is a missing connection in the load port, and the specific phase where the missing connection occurred can be located based on the port with the abnormally low phase voltage.

[0107] The following is a detailed description of a circuit structure consisting of multiple power conversion devices, with the second detection target being the phase sequence consistency status.

[0108] Phase sequence consistency detection refers to checking whether the phase sequence of the grid port and load port of each power conversion device is consistent. To achieve this detection, it is necessary to control the relays in the master power conversion device to engage, so as to lead the grid voltage to the load port, and control the relays between the grid port and load port of the remaining slave power conversion devices to disengage. Since the second detection target is the phase sequence consistency status, the phase voltage corresponding to the target port is the phase voltage of each phase of the grid port and the phase voltage of each phase of the load port.

[0109] In actual implementation, specific situations where the phase sequence of each power grid port and the load port is inconsistent include: 1) In such Figure 17 In the scenario depicting an abnormal two-phase sequence in the power conversion equipment, the grid port (grid side) wiring of the slave power conversion equipment is normal, but two phases of its load port (load side) are incorrectly connected when the load is connected. For example, the load port corresponding to the first relay (Relay_1) of the slave power conversion equipment is incorrectly connected to phase B of the load, and the load port corresponding to the second relay (Relay_2) is incorrectly connected to phase A of the load. If the relays of the slave power conversion equipment are directly activated under this condition, the phase A voltage of the grid will sequentially pass through the relays of the master power conversion equipment, the phase A line of the load, the phase A connection terminal of the slave power conversion equipment, and the second relay (Relay_2) of the slave power conversion equipment, ultimately short-circuiting in reverse to the phase B line of the grid, thus causing a short circuit fault between the two phases of the grid.

[0110] 2) such as Figure 18 and Figure 19 The following scenario illustrates a three-phase sequence abnormality in a power conversion device: (e.g.) Figure 18 In the scenario shown, where the overall phase sequence of the grid ports leads the phase sequence of the load ports, the grid-side wiring of the slave energy conversion device is normal, but the load phases A, B, and C ports of the slave energy conversion device are incorrectly connected to phases B, C, and A of the load, respectively. In such cases... Figure 19 In the scenario shown where the overall phase sequence of the power grid ports lags behind the phase sequence of the load ports, the grid-side wiring of the slave power conversion device is normal, but the load phases A, B, and C ports of the slave power conversion device are incorrectly connected to phases C, A, and B of the load, respectively. Under any of these three-phase misalignment conditions, a short circuit will occur between the three phases of the power grid.

[0111] When the phase sequence of the grid ports and load ports is inconsistent, the voltage difference between the grid ports and load ports is the line voltage. Therefore, the voltage difference U between the three-phase grid ports and load ports can be sampled. grid_loadxn (x=A, B, C) and determine whether the voltage difference is the line voltage, thereby determining whether there is a phase sequence inconsistency; further, the number of phases with inconsistent phase sequence can be determined based on the number of phases with statistical voltage differences that are the line voltage.

[0112] According to the wiring detection method provided in the embodiments of this application, when the circuit structure consists of multiple power conversion devices, corresponding to the missing wiring, incorrect wiring, and phase sequence consistency status in the detection target, under the premise that the host relay is energized and the slave relay is de-energized, the phase voltage of the load port of the power conversion device under test, or the phase voltage of the grid port and the load port, are obtained respectively. Furthermore, combined with the specific voltage characteristics of the power conversion device under test under different wiring topologies, the port or phase of the wiring abnormality is determined, which helps to conduct targeted troubleshooting of specific fault nodes, thereby reducing the difficulty of wiring fault troubleshooting and location, and improving the efficiency of wiring fault troubleshooting and location.

[0113] Step 120: Determine the wiring status corresponding to the detection target based on the phase voltage.

[0114] In this step, the phase voltage is determined based on the detection target and the circuit structure of the power conversion system provided in step 110 above and any embodiment, and will not be described again.

[0115] In some embodiments, step 120 includes: If the first detection target is a missing connection and the phase voltage is less than or equal to the first voltage threshold, it is determined that there is a missing connection at the grid port corresponding to the phase voltage. If the first detection target is a wiring misconnection, and the difference between the phase voltage of one phase and the grid phase voltage is less than or equal to the second voltage threshold, and the difference between the phase voltage of the remaining phases and the grid line voltage is less than or equal to the third voltage threshold, then it is determined that there is a wiring misconnection at the grid port corresponding to the phase voltage whose difference between the phase voltage and the grid phase voltage is less than or equal to the second voltage threshold. If the first detection target is a mixed wiring connection and the phase voltage is less than or equal to the fourth voltage threshold, it is determined that there is no mixed wiring connection between the load port and the grid port corresponding to the phase voltage.

[0116] In this embodiment, the first voltage threshold, the second voltage threshold, the third voltage threshold, and the fourth voltage threshold are judgment criteria set based on the missing wiring, incorrect wiring, and mixed wiring in the first detection target, respectively. Depending on the actual application scenario, the values ​​of the above thresholds can be the same or different, and this application does not make specific limitations in this regard.

[0117] The difference between the phase voltage of one phase and the phase voltage (or line voltage) of the power grid refers to the difference or deviation between the actual value of the phase voltage at the power grid port of the power conversion equipment and the reference value of the corresponding phase voltage (or line voltage) of the power grid under normal wiring conditions.

[0118] In some embodiments, the first voltage threshold to the fourth voltage threshold may include, but are not limited to, the determination threshold corresponding to the effective value (Root Mean Square, RMS) of the phase voltage, the determination threshold corresponding to the voltage peak value, or the determination threshold corresponding to the instantaneous amplitude value.

[0119] For detecting missing or mixed wiring, the first and fourth voltage thresholds can be set to low effective value judgment thresholds, such as a small positive voltage value close to 0.

[0120] For the detection of incorrect wiring, the second and third voltage thresholds can be set based on the allowable error ranges of the grid phase voltage and grid line voltage, respectively.

[0121] For ease of description, the judgment case where "the difference between the phase voltage of one phase and the grid phase voltage is less than or equal to the second voltage threshold" will be referred to as "phase voltage equals grid phase voltage"; correspondingly, the judgment case where "the difference between the phase voltage of the remaining phases and the grid line voltage is less than or equal to the third voltage threshold" will be referred to as "phase voltage equals grid line voltage".

[0122] The following is combined Figure 5 This document explains the detection process for mixed wiring when the circuit structure is a single power conversion device.

[0123] Control the power conversion equipment to disconnect all relays so that the load port should be de-energized under normal wiring conditions; The three-phase phase voltage U at each load port of the sampling power conversion equipment load_xn (x=A, B, C); Determine whether all three phase voltages at the load port are less than or equal to the fourth voltage threshold (threshold, threshold). If the judgment result is yes (Y), that is, the three-phase voltage ≤ thres (fourth voltage threshold), then it is determined that the load port wiring is normal, that is, there is no wiring misconnection between the load port and the grid port corresponding to the three-phase voltage; If the judgment result is negative (N), that is, the phase voltage of a certain phase is greater than the fourth voltage threshold, then it is determined that there is a wiring misconnection between the load port and the grid port corresponding to the phase voltage.

[0124] The following is combined Figure 8 This document explains the detection process for incorrect wiring when the circuit structure is a single power conversion device.

[0125] Disconnect all relays from the control power conversion equipment; Sample the three-phase phase voltage U at the grid port grid_xn (x=A, B, C); Based on the acquired phase voltage, a judgment is made in conjunction with preset second and third voltage thresholds. The second voltage threshold is set based on the allowable error range between the phase voltage (Un) and the grid phase voltage, while the third voltage threshold is based on the grid line voltage (Un). Setting the allowable error range between Un); If the judgment result is (Y), that is, the phase voltage of a certain phase is equal to the grid phase voltage, such as the rated phase voltage of the grid, and the phase voltages of the other two phases are equal to the grid line voltage, such as the rated line voltage of the grid, then it is determined that there is a wiring misconnection (i.e., the live wire and neutral wire of that phase are misconnected) at the grid port corresponding to the phase voltage whose difference from the grid phase voltage is less than or equal to the second voltage threshold. If the judgment result is negative (N), that is, all three phase voltage samples are grid phase voltages, then it is determined that there is no incorrect wiring at the grid port (i.e., the wiring is normal).

[0126] The following is combined Figure 10 This document explains the detection process for missing wiring when the circuit structure is a single power conversion device.

[0127] Disconnect all relays from the power conversion equipment; Sample the three-phase phase voltage U at the grid port grid_xn (x=A, B, C); Determine whether the phase voltage of each phase at the grid port is less than or equal to the first voltage threshold (threshold, threshold). If the judgment result is yes (Y), that is, the phase voltage of a certain phase is ≤thres (first voltage threshold), then it is determined that there is a missing connection at the power grid port corresponding to the phase voltage (i.e., the live wire of that phase is missing). If the judgment result is negative (N), that is, the phase voltage of a certain phase is greater than the first voltage threshold, then it is determined that there is no missing connection at the grid port corresponding to the phase voltage (that is, the phase connection is normal).

[0128] In some embodiments, step 120 includes: If the second detection target is a missing connection and the phase voltage is less than or equal to the fifth voltage threshold, it is determined that there is a missing connection at the load port corresponding to the phase voltage. If the second detection target is a wiring misconnection, and the difference between the phase voltage of one phase and the grid phase voltage is less than or equal to the sixth voltage threshold, and the difference between the phase voltage of the remaining phases and the grid line voltage is less than or equal to the seventh voltage threshold, then it is determined that the load port corresponding to the phase voltage whose difference between the phase voltage and the grid phase voltage is less than or equal to the sixth voltage threshold has a wiring misconnection.

[0129] In this embodiment, the fifth voltage threshold, the sixth voltage threshold, and the seventh voltage threshold are judgment criteria set based on the missing and incorrect wiring in the first detection target, respectively. Depending on the actual application scenario, the values ​​of the above thresholds may be the same or different, and this application does not make specific limitations in this regard.

[0130] It is understandable that the fifth to seventh voltage thresholds are set in the same way as the first to fourth voltage thresholds mentioned earlier, so they will not be repeated here.

[0131] The difference between the phase voltage of one phase and the grid phase voltage (or grid line voltage) refers to the difference or deviation between the actual value of the phase voltage at the load port of the power conversion equipment and the reference value of the grid phase voltage (or grid line voltage) under normal wiring conditions.

[0132] For ease of description, the judgment case where "the difference between the phase voltage of one phase and the grid phase voltage is less than or equal to the sixth voltage threshold" will be referred to as "phase voltage equals grid phase voltage"; correspondingly, the judgment case where "the difference between the phase voltage of the remaining phases and the grid line voltage is less than or equal to the seventh voltage threshold" will be referred to as "phase voltage equals grid line voltage".

[0133] The following is combined Figure 14 This document explains the detection process for incorrect wiring when the circuit structure consists of multiple power conversion devices.

[0134] The relay inside the main power conversion device is activated to bring the grid voltage to the load port; at the same time, the relays of the other power conversion devices (slave devices) are kept in the open state. In the case where an electrical connection is established between the grid port and the load port of the target power conversion device to bring the grid voltage to the load port, and the electrical connection between the grid port and the load port of all other power conversion devices except the target power conversion device is disconnected, The three-phase phase voltage U at the sampling load port load_xn (x=A, B, C); Similar to the previous method for detecting incorrect neutral and live wire connections at the power grid port, the judgment is made based on the collected phase voltage, combined with preset sixth and seventh voltage thresholds. The sixth voltage threshold is set based on the allowable error range relative to the power grid phase voltage (Un), and the seventh voltage threshold is set based on the allowable error range relative to the power grid line voltage (Un). The allowable error range setting for Un); If the judgment result is (Y), that is, the phase voltage of a certain phase is equal to the grid phase voltage, such as the rated phase voltage of the grid, and the phase voltages of the other two phases are equal to the grid line voltage, such as the rated line voltage of the grid, then it is determined that the load port corresponding to the phase voltage whose difference from the grid phase voltage is less than or equal to the sixth voltage threshold has a wiring error (i.e., the live wire and neutral wire of that phase are incorrectly connected). If the judgment result is negative (N), that is, the three-phase phase voltage samples are all grid phase voltages, then it is determined that there is no incorrect wiring at the load port (i.e. the wiring is normal).

[0135] The following is combined Figure 16 This document explains the detection process for missing wiring when the circuit structure consists of multiple power conversion devices.

[0136] The relay inside the main power conversion device is activated to bring the grid voltage to the load port; at the same time, the relays of the other power conversion devices (slave devices) are kept in the open state. The three-phase phase voltage U at the sampling load port load_xn (x=A, B, C); Similar to detecting missing connections at the grid port mentioned earlier, determine whether the phase voltage of each phase at the load port is less than or equal to the fifth voltage threshold (threshold, threshold). If the judgment result is yes (Y), that is, the phase voltage of a certain phase is ≤thres (the fifth voltage threshold), then it is determined that there is a missing connection at the load port corresponding to the phase voltage (i.e., the load line of that phase is missing). If the judgment result is negative (N), that is, the phase voltage of a certain phase is greater than the fifth voltage threshold, then it is determined that there is no missing connection at the load port corresponding to the phase voltage (that is, the phase connection is normal).

[0137] In some embodiments, step 120 further includes: When the second detection target is the phase sequence consistency state, based on the phase voltage of each phase at the grid port and the phase voltage of each phase at the load port, the number of phases whose difference between the phase voltage difference and the grid line voltage is less than or equal to the eighth voltage threshold is obtained. When the number of phases is the first quantity, ensure that the phase sequence between the grid port and the load port is consistent; If the number of phases is not the first number, it is determined that the phase sequence between the grid port and the load port is inconsistent.

[0138] In this embodiment, the eighth voltage threshold is a criterion set based on the phase sequence consistency status.

[0139] The phase voltage difference is determined based on the phase voltage of each phase at the grid port and the phase voltage of each phase at the load port.

[0140] The difference between phase voltage differential and grid line voltage refers to the difference or deviation between the actual value of phase voltage differential and the value of grid line voltage.

[0141] The number of phases with a difference less than or equal to the eighth voltage threshold indicates the number of phases with inconsistent phase sequence between the grid port and the load port.

[0142] The first quantity can be set to 0. When the number of phases is the first quantity (i.e., the number of phases is 0), it means that the number of phases that meet the above-mentioned difference degree is less than or equal to the eighth voltage threshold is 0, that is, the phase sequence of each phase is consistent.

[0143] The number of phases that is not the first can be set to be greater than the first number. For example, in a three-phase power conversion system, the number of phases that is not the first can be 2 or 3. "Not the first number" means that the number of phases is greater than the first number (i.e., greater than 0). For example, in a three-phase power conversion system, the number of phases can be 2 or 3, meaning that the phase sequence between the grid port and the load port is inconsistent.

[0144] In some embodiments, the eighth voltage threshold may be set based on the allowable error range relative to the grid line voltage.

[0145] For ease of description, the judgment condition that "the difference between the phase voltage difference and the grid line voltage is less than or equal to the eighth voltage threshold" will be referred to as "the phase voltage difference equals the line voltage"; correspondingly, the number of phases that satisfy this judgment condition will be referred to as "the number of times the voltage difference equals the line voltage".

[0146] In some embodiments, after step 120, the method further includes: Based on the number of phases, determine the number of times the phase sequence of the grid port and the load port is inconsistent.

[0147] It should be noted that the technical solution of this application is not limited to three-phase systems, but is also applicable to multi-phase power supply systems with N (N>3) phases. In multi-phase power supply systems, the number of phases exhibiting line voltage characteristics can also be greater than 3.

[0148] In some embodiments, determining the number of phase sequence inconsistencies between the grid port and the load port based on the number of phases includes: When the number of phases is the second number, the phase sequence of the second number of phases at the grid port and the load port is inconsistent; When the number of phases is the third, it is determined that the phase sequence of the third number of phases at the grid port and the load port is inconsistent; If the number of phases is greater than the third number, it is determined that the phase sequence of the third or more phases at the grid port and the load port is inconsistent.

[0149] In this embodiment, the second quantity and the third quantity are preset judgment criteria corresponding to different phase sequence wiring error modes. For example, the second quantity is 2, which can correspond to the wiring condition in which the positions of two local live wires in a three-phase power supply system cross; the third quantity is 3, which can correspond to the wiring condition in which the overall phase shift or misalignment of the three live wires in a three-phase power supply system.

[0150] The following is combined Figure 20 The detection process for phase sequence consistency is explained when the circuit structure consists of multiple power conversion devices.

[0151] The system controls the relays inside the power conversion device (which acts as the master unit) to engage, while simultaneously controlling the relays in the slave unit to remain disconnected.

[0152] When the phase sequence at the grid port and the load port is inconsistent, the grid-load voltage difference of the slave device will exhibit line voltage characteristics. Obtain the three-phase grid-load voltage difference U of the slave device. grid_loadxn (x=A, B, C), count the number of times N is the voltage difference equal to the grid line voltage: Determine if N is equal to 0: If the result is yes (Y), it means that the voltage difference between each phase is not the line voltage, and the wiring is normal (i.e., the phase sequence is consistent); if the result is no (N), proceed to the next step of judgment.

[0153] Determine if N equals 2: If the result is yes (Y), then it is determined that a two-phase phase sequence wiring abnormality has occurred. Swapping the wiring of the two phases will resolve the fault. If the judgment result is negative (N), it indicates that there is a three-phase sequence inconsistency, i.e., N=3, which can be divided into the following categories: Figure 18 or Figure 19 There are two scenarios.

[0154] To further differentiate, the phase angle θ_grid of the phase-locked loop at the grid port and the phase-locked loop θ_load at the load port are calculated separately, and the misalignment type can be determined by comparing the phase difference between the two phase-locked loops. If the grid phase-locked loop (PLL) leads the load PLL phase, it is determined that the grid port connection phase leads the load port connection phase (corresponding to...). Figure 18 If the grid phase-locked loop lags behind the load phase-locked loop phase, then the grid port connection phase is determined to lag behind the load port connection phase (corresponding to...). Figure 19 ).

[0155] The wiring detection method provided in this application can be executed by a wiring detection device. This application uses a wiring detection device executing the wiring detection method as an example to illustrate the wiring detection device provided in this application.

[0156] This application also provides a wiring detection device.

[0157] like Figure 23 As shown, the wiring detection device includes: a first processing module 2310 and a second processing module 2320.

[0158] The first processing module 2310 is used to acquire the phase voltage corresponding to the target port when controlling each power conversion device to be in the corresponding working state; the target port is at least one of multiple grid ports and multiple load ports, and the target port is determined based on the detection target and the circuit structure of the power conversion system. The second processing module 2320 is used to determine the wiring status corresponding to the detection target based on the phase voltage.

[0159] According to the wiring detection device provided in the embodiments of this application, by acquiring the phase voltage of the target port while controlling each power conversion device to be in the corresponding working state, the electrical interference of internal unrelated circuits is reduced, so that the collected voltage data can truly reflect the external physical wiring situation; at the same time, the target port is determined based on the detection target and the circuit structure of the power conversion system, and the corresponding voltage sampling port can be selectively selected according to the specific fault type to be investigated and the single / parallel architecture, reducing redundant sampling and unnecessary detection of irrelevant ports, thereby reducing the difficulty of wiring fault investigation and location.

[0160] In some embodiments, the first processing module 2310 may also be used for: In the case of a single power conversion device in a circuit structure, the phase voltage of the grid port or load port is obtained based on a first detection target; the first detection target includes: missing wiring, incorrect wiring, or mixed wiring. In the case of a circuit structure consisting of multiple power conversion devices, the phase voltage of the load port or the phase voltage of the load port and the phase voltage of the grid port are obtained based on the second detection target; the second detection target includes: missing wiring, incorrect wiring, or phase sequence consistency status.

[0161] In some embodiments, the first processing module 2310 may also be used for: When the first detection target is a mixed wiring, the phase voltage of each phase of the load port is determined as the phase voltage corresponding to the target port. When the first detection target is a missing or incorrect wiring connection, the phase voltage of each phase at the grid port is determined as the phase voltage corresponding to the target port.

[0162] In some embodiments, the second processing module 2320 may also be used for: If the first detection target is a missing connection and the phase voltage is less than or equal to the first voltage threshold, it is determined that there is a missing connection at the grid port corresponding to the phase voltage. If the first detection target is a wiring misconnection, and the difference between the phase voltage of one phase and the grid phase voltage is less than or equal to the second voltage threshold, and the difference between the phase voltage of the remaining phases and the grid line voltage is less than or equal to the third voltage threshold, then it is determined that there is a wiring misconnection at the grid port corresponding to the phase voltage whose difference between the phase voltage and the grid phase voltage is less than or equal to the second voltage threshold. If the first detection target is a mixed wiring connection and the phase voltage is less than or equal to the fourth voltage threshold, it is determined that there is no mixed wiring connection between the load port and the grid port corresponding to the phase voltage.

[0163] In some embodiments, the first processing module 2310 may also be used for: When the second detection target is a missing or incorrect wiring connection, the phase voltage of each phase of the load port is determined as the phase voltage corresponding to the target port. When the second detection target is the phase sequence consistency state, the phase voltage of each phase of the grid port and the phase voltage of each phase of the load port are determined as the phase voltage corresponding to the target port.

[0164] In some embodiments, the second processing module 2320 may also be used for: If the second detection target is a missing connection and the phase voltage is less than or equal to the fifth voltage threshold, it is determined that there is a missing connection at the load port corresponding to the phase voltage. If the second detection target is a wiring misconnection, and the difference between the phase voltage of one phase and the grid phase voltage is less than or equal to the sixth voltage threshold, and the difference between the phase voltage of the remaining phases and the grid line voltage is less than or equal to the seventh voltage threshold, then it is determined that there is a wiring misconnection at the load port corresponding to the phase voltage whose difference between the phase voltage and the grid phase voltage is less than or equal to the sixth voltage threshold.

[0165] In some embodiments, the second processing module 2320 may also be used for: When the second detection target is the phase sequence consistency state, based on the phase voltage of each phase at the grid port and the phase voltage of each phase at the load port, the number of phases whose difference between the phase voltage difference and the grid line voltage is less than or equal to the eighth voltage threshold is obtained. When the number of phases is the first quantity, ensure that the phase sequence between the grid port and the load port is consistent; If the number of phases is not the first number, it is determined that the phase sequence between the grid port and the load port is inconsistent.

[0166] In some embodiments, the wiring detection device may further include a third processing module for: Based on the number of phases, determine the number of times the phase sequence of the grid port and the load port is inconsistent.

[0167] In some embodiments, the third processing module may also be used for: When the number of phases is the second number, the phase sequence of the second number of phases at the grid port and the load port is inconsistent; When the number of phases is the third, it is determined that the phase sequence of the third number of phases at the grid port and the load port is inconsistent; If the number of phases is greater than the third number, it is determined that the phase sequence of the third or more phases at the grid port and the load port is inconsistent.

[0168] In some embodiments, the first processing module 2310 may also be used for: In the case of a single power conversion device in a circuit structure, the electrical connection between the grid port and the load port of the power conversion device is disconnected. In the case of a circuit structure consisting of multiple power conversion devices, the system controls the establishment of an electrical connection between the grid port and the load port of the target power conversion device to bring the grid voltage to the load port, and controls the disconnection of the electrical connection between the grid port and the load port of all other power conversion devices except the target power conversion device; wherein, the target power conversion device is any one of the multiple power conversion devices.

[0169] The wiring detection device in this application embodiment can be an electronic device or a component within an electronic device, such as an integrated circuit or a chip. The electronic device can be a terminal or other devices besides a terminal; this application embodiment does not impose specific limitations.

[0170] The wiring detection device in this application embodiment can be a device with an operating system. This operating system can be Android, iOS, or other possible operating systems; this application embodiment does not specifically limit it.

[0171] The wiring detection device provided in this application embodiment can achieve... Figures 1 to 22 The various processes implemented in the method implementation examples will not be described again here to avoid repetition.

[0172] This application also provides a power conversion device, including: multiple terminals.

[0173] The power conversion equipment detects the wiring status based on the wiring detection method provided in any of the above embodiments.

[0174] In some embodiments, such as Figure 2 As shown, the terminals include power grid terminals connected to the power grid port and load terminals connected to the load port. To avoid repetition, they will not be described again.

[0175] In some embodiments, the power conversion device further includes: a plurality of switches.

[0176] In this embodiment, multiple switches are used to connect the load terminal and the corresponding power grid terminal.

[0177] This application also provides a power conversion system, including at least one power conversion device.

[0178] The power conversion system detects the wiring status based on the wiring detection method provided in any embodiment.

[0179] like Figure 2 As shown, the power conversion system includes multiple grid ports for connecting to the power grid and multiple load ports for connecting to the load. To avoid repetition, these will not be described in detail.

[0180] In some embodiments, when the power conversion system includes multiple power conversion devices, the grid port of each power conversion device is connected in parallel to the power grid, and the load port of each power conversion device is connected in parallel to the load.

[0181] In some embodiments, such as Figure 24As shown, this application embodiment also provides an electronic device 2400, including a processor 2401, a memory 2402, and a computer program stored in the memory 2402 and executable on the processor 2401. When the program is executed by the processor 2401, it implements the various processes of the above-described wiring detection method embodiment and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0182] It should be noted that the electronic devices in the embodiments of this application include the mobile electronic devices and non-mobile electronic devices described above.

[0183] This application also provides a non-transitory computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the various processes of the above-described wiring detection method embodiments and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0184] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0185] This application also provides a computer program product, including a computer program that, when executed by a processor, implements the above-described wiring detection method.

[0186] The processor is the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0187] This application embodiment also provides a chip, which includes a processor and a communication interface. The communication interface is coupled to the processor. The processor is used to run programs or instructions to implement the various processes of the above-described wiring detection method embodiment and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0188] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0189] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0190] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a computer software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0191] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

[0192] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0193] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A method of detecting a connection, characterized by, An application is made in a power conversion system, the power conversion system including at least one power conversion device, the power conversion system including multiple grid ports for connection to the power grid and multiple load ports for connection to loads; the method includes: While controlling each power conversion device to be in its corresponding working state, the phase voltage corresponding to the target port is obtained; the target port is at least one of the plurality of grid ports and the plurality of load ports, and the target port is determined based on the detection target and the circuit structure of the power conversion system; Based on the phase voltage, the wiring status corresponding to the detection target is determined.

2. The method of claim 1, wherein The step of obtaining the phase voltage corresponding to the target port while controlling each power conversion device to be in its corresponding operating state includes: In the case where the circuit structure is a single power conversion device, the phase voltage of the grid port or load port is obtained based on a first detection target; the first detection target includes: missing wiring, incorrect wiring, or mixed wiring. In the case where the circuit structure consists of multiple power conversion devices, the phase voltage of the load port or the phase voltage of the load port and the phase voltage of the grid port are obtained based on the second detection target; the second detection target includes: missing wiring, incorrect wiring, or phase sequence consistency status.

3. The wiring detection method according to claim 2, characterized in that, In the case where the circuit structure is a single power conversion device, obtaining the phase voltage of the grid port or load port based on the first detection target includes: In the case where the first detection target is a mixed wiring, the phase voltage of each phase of the load port is determined as the phase voltage corresponding to the target port; If the first detection target is a missing or incorrect wiring connection, the phase voltage of each phase of the power grid port is determined as the phase voltage corresponding to the target port.

4. The wiring detection method according to claim 3, characterized in that, Determining the wiring state corresponding to the detection target based on the phase voltage includes: If the first detection target is a missing connection and the phase voltage is less than or equal to a first voltage threshold, it is determined that the missing connection exists at the power grid port corresponding to the phase voltage. If the first detection target is a wiring misconnection, and the difference between the phase voltage of one phase and the grid phase voltage is less than or equal to a second voltage threshold, and the difference between the phase voltage of the remaining phases and the grid line voltage is less than or equal to a third voltage threshold, then it is determined that the grid port corresponding to the phase voltage whose difference from the grid phase voltage is less than or equal to the second voltage threshold has the wiring misconnection. If the first detection target is a mixed wiring connection, and the phase voltage is less than or equal to the fourth voltage threshold, it is determined that there is no mixed wiring connection between the load port and the grid port corresponding to the phase voltage.

5. The method of claim 2, wherein In the case where the circuit structure comprises multiple power conversion devices, obtaining the phase voltage of the load port or the phase voltage of the load port and the phase voltage of the grid port based on the second detection target includes: When the second detection target is a missing or incorrect wiring connection, the phase voltage of each phase of the load port is determined as the phase voltage corresponding to the target port. When the second detection target is in a phase sequence consistency state, the phase voltage of each phase of the grid port and the phase voltage of each phase of the load port are determined as the phase voltage corresponding to the target port.

6. The method of claim 5, wherein, Determining the wiring state corresponding to the detection target based on the phase voltage includes: If the second detection target is a missing connection and the phase voltage is less than or equal to the fifth voltage threshold, it is determined that the missing connection exists at the load port corresponding to the phase voltage. If the second detection target is a wiring misconnection, and the difference between the phase voltage of one phase and the grid phase voltage is less than or equal to the sixth voltage threshold, and the difference between the phase voltage of the remaining phases and the grid line voltage is less than or equal to the seventh voltage threshold, then it is determined that the load port corresponding to the phase voltage whose difference between the phase voltage and the grid phase voltage is less than or equal to the sixth voltage threshold has the wiring misconnection.

7. The method of claim 5, wherein Determining the wiring state corresponding to the detection target based on the phase voltage includes: When the second detection target is a phase sequence consistency state, based on the phase voltage of each phase of the grid port and the phase voltage of each phase of the load port, the number of phases whose difference between the phase voltage difference and the grid line voltage is less than or equal to the eighth voltage threshold is obtained. When the number of phases is a first quantity, it is determined that the phase sequence between the power grid port and the load port is consistent; If the number of phases is not a first number, it is determined that the phase sequence between the power grid port and the load port is inconsistent.

8. The method of claim 7, wherein, After determining the phase sequence inconsistency between the grid port and the load port, the method further includes: Based on the number of phases, determine the number of times the phase sequence of the power grid port and the load port is inconsistent.

9. The method of claim 8, wherein, Determining the number of times the phase sequence of the power grid port and the load port is inconsistent based on the number of phases includes: When the number of phases is the second quantity, it is determined that the phase sequence of the second quantity of phases at the power grid port and the load port is inconsistent; When the number of phases is the third number, it is determined that the phase sequence of the third number of phases at the power grid port and the load port is inconsistent; If the number of phases is greater than a third number, it is determined that the phase sequence of the third or more phases at the power grid port and the load port is inconsistent.

10. The method of claim 1-9, wherein, The step of obtaining the phase voltage corresponding to the target port while controlling each power conversion device to be in its corresponding operating state includes: In the case where the circuit structure is a single power conversion device, the electrical connection between the grid port and the load port of the power conversion device is disconnected. In the case where the circuit structure comprises multiple power conversion devices, an electrical connection is established between the grid port and the load port of the target power conversion device to bring the grid voltage to the load port, and the electrical connection between the grid port and the load port of all other power conversion devices except the target power conversion device is disconnected; wherein, the target power conversion device is any one of the multiple power conversion devices.

11. A wiring detection device characterized by comprising: An application in a power conversion system, the power conversion system including at least one power conversion device, the power conversion system including multiple grid ports for connection to the power grid and multiple load ports for connection to loads, the device comprising: The first processing module is used to acquire the phase voltage corresponding to the target port while controlling each power conversion device to be in the corresponding working state; the target port is at least one of the plurality of grid ports and the plurality of load ports, and the target port is determined based on the detection target and the circuit structure of the power conversion system. The second processing module is used to determine the wiring status corresponding to the detection target based on the phase voltage.

12. An electric energy conversion device, characterized by include: Multiple terminals, including: a power grid terminal connected to a power grid port and a load terminal connected to a load port; The power conversion equipment detects the wiring status based on the wiring detection method as described in any one of claims 1-10.

13. The power conversion device according to claim 12, characterized in that, The power conversion equipment includes: Multiple switches are used to connect the load terminals and the corresponding power grid terminals.

14. A power conversion system, characterized in that, include: At least one power conversion device, the power conversion system comprising a plurality of grid ports for connection to the power grid and a plurality of load ports for connection to loads; The power conversion system detects the wiring status based on the wiring detection method as described in any one of claims 1-10.

15. The electric energy conversion system of claim 14, wherein, In the case where the power conversion system includes multiple power conversion devices, the grid port of each power conversion device is connected in parallel to the power grid, and the load port of each power conversion device is connected in parallel to the load.

Images