Power grid phase sequence determination method, controller and system of power converter

Abstract

The invention relates to a power grid phase sequence determination method of a power converter, a controller and a system. The method of one aspect is used in a first controller, and comprises the following steps: when all single-phase power converters are in a grid-connected power generation state, controlling other phase circuits in a multi-phase power grid system to be disconnected from corresponding single-phase power converters, and sending a first state query request to each single-phase power converter, and according to received first feedback information corresponding to the first state query request, determining a single-phase power converter of which the power grid phase sequence is a target phase circuit, the target phase circuit corresponding to any phase circuit in the multi-phase power grid system, and the other phase circuits corresponding to phase circuits except the target phase circuit in the multi-phase power grid system. By adopting the method, the accuracy of power grid phase sequence determination can be improved.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a method, controller, controller and system for determining a power grid phase sequence of a power converter. Background Art

[0002] In a photovoltaic three-phase system, multiple single-phase power converters (such as micro inverters) are connected to the first phase circuit, the second phase circuit and the third phase circuit of the three-phase grid system. In order to improve power generation efficiency or balance the three-phase output, it is necessary to accurately determine the grid phase sequence of each single-phase power converter in the three-phase grid system, that is, to determine which phase circuit each single-phase power converter is connected to, so as to control the single-phase power converter corresponding to each phase circuit separately.

[0003] However, because the physical distance between each phase line is very close, when each single-phase power converter communicates with the controller, the communication signal may be crosstalked between each phase. Therefore, when determining the grid phase sequence of the single-phase power converter in the three-phase grid system, the controller cannot accurately distinguish the signals from each phase, resulting in low accuracy of the grid phase sequence determination results of each single-phase power converter. Summary of the invention

[0004] Based on this, it is necessary to provide a method, controller and system for determining the grid phase sequence of a power converter with high accuracy in order to solve the above technical problems.

[0005] In a first aspect, the present application provides a method for determining a grid phase sequence of a power converter, the method being used for a first controller, and the method being used to determine a grid phase sequence corresponding to each single-phase power converter connected to a multi-phase grid system; the method comprising:

[0006] When all single-phase power converters are in a state of grid-connected power generation, controlling the remaining phase circuits in the multi-phase power grid system to be disconnected from the corresponding single-phase power converters;

[0007] Sending a first status query request to each single-phase power converter;

[0008] Determine, according to the received first feedback information corresponding to the first state query request, a single-phase power converter whose grid phase sequence is a target phase circuit;

[0009] The target phase circuit corresponds to any phase circuit in the multi-phase power grid system, and the remaining phase circuits correspond to phase circuits other than the target phase circuit in the multi-phase power grid system.

[0010] In one embodiment, the communication method between the first controller and each single-phase power converter includes a wireless communication method or a power carrier communication method;

[0011] Determining the grid phase sequence as a single-phase power converter of a target circuit according to the received first feedback information corresponding to the first state query request, including:

[0012] Determine the grid phase sequence of the single-phase power converter whose first feedback information includes first state information as the target phase circuit, wherein the first state information is used to indicate that the corresponding single-phase power converter is in a working state;

[0013] The grid phase sequence of the single-phase power converter whose first feedback information includes second state information is determined to be not a target phase circuit, and the second state information is used to indicate that the corresponding single-phase power converter is not in a working state.

[0014] In one of the embodiments, the communication method between the first controller and each single-phase power converter includes a one-to-one wired communication method;

[0015] Determining, according to the received first feedback information corresponding to the first state query request, a single-phase power converter whose grid phase sequence is a target phase circuit, comprising:

[0016] The grid phase sequence of the single-phase power converter that feeds back the first feedback information is determined as a target phase circuit.

[0017] In one embodiment, the multi-phase power grid system is a three-phase power grid system, the target phase circuit includes a first phase circuit, and the remaining phase circuits include a second phase circuit and a third phase circuit;

[0018] Controlling the remaining phase circuits in the multi-phase power grid system to be disconnected from the corresponding single-phase power converters, including: controlling the second phase circuit and the third phase circuit to be disconnected from the corresponding single-phase power converters;

[0019] Determining, according to the received first feedback information corresponding to the first state query request, a single-phase power converter whose grid phase sequence is a target phase circuit, comprising:

[0020] According to the first feedback information, it is determined that the phase sequence of the power grid is a single-phase power converter of the first phase circuit.

[0021] In one embodiment, after determining the grid phase sequence as a single-phase power converter of a target phase circuit according to the received first feedback information corresponding to the first status query request, the method further includes:

[0022] Controlling the second phase circuit and the third phase circuit to be connected to corresponding single-phase power converters;

[0023] When all the single-phase power converters are in a state of grid-connected power generation, controlling the first phase circuit and the third phase circuit to be disconnected from the corresponding single-phase power converters;

[0024] Sending a second state query request to each single-phase power converter whose grid phase sequence is not the first phase circuit;

[0025] According to the received second feedback information corresponding to the second state query request, it is determined that the phase sequence of the power grid is a single-phase power converter of the second phase circuit.

[0026] In one embodiment, after determining that the grid phase sequence is a single-phase power converter of a second phase circuit according to the received second feedback information corresponding to the second state query request, the method further includes:

[0027] Controlling the first phase circuit and the third phase circuit to be connected to corresponding single-phase power converters;

[0028] When all single-phase power converters are in a state of grid-connected power generation, controlling the first phase circuit and the second phase circuit to be disconnected from the corresponding single-phase power converters;

[0029] Sending a third state query request to each single-phase power converter whose grid phase sequence is not the first phase circuit and the second phase circuit;

[0030] According to the received third feedback information corresponding to the third state query request, it is determined that the phase sequence of the power grid is a single-phase power converter of the third phase circuit.

[0031] In one embodiment, after determining that the grid phase sequence is a single-phase power converter of a second phase circuit according to the received second feedback information corresponding to the second state query request, the method further includes:

[0032] The grid phase sequence of the single-phase power converter whose grid phase sequence is not the first phase circuit and the second phase circuit is determined as the third phase.

[0033] In one embodiment, the following steps are followed to determine whether all single-phase power converters are in a state of grid-connected power generation:

[0034] Sending a fourth state query request to all single-phase power converters;

[0035] If the first number is equal to the second number, it is determined that all single-phase power converters are in a state of grid-connected power generation; the first number is the number of fourth feedback information corresponding to the fourth state query request received within a preset time length, and the second number is the number of single-phase power converters connected to the multi-phase power grid system;

[0036] If the first number is not equal to the second number, it is determined that not all single-phase power converters are in the state of grid-connected power generation.

[0037] In a second aspect, the present application provides a method for determining a grid phase sequence of a power converter, the method being used in a first controller, the first controller being communicatively connected to a second controller, the second controller being used to control the on / off between each single-phase power converter and a corresponding phase circuit of a multi-phase grid system, the method being used to determine the grid phase sequence corresponding to each single-phase power converter connected to the multi-phase grid system, the method comprising:

[0038] When all single-phase power converters are in a state of grid-connected power generation, a first control signal is sent to the second controller, where the first control signal is used for the second controller to execute opening of the remaining switches;

[0039] Sending a first status query request to each single-phase power converter;

[0040] Determine, according to the received first feedback information corresponding to the first state query request, a single-phase power converter whose grid phase sequence is a target phase circuit;

[0041] Among them, the remaining switches are used to control the on and off of the single-phase power converters and the remaining phase circuits corresponding to the remaining phase circuits in the multi-phase power grid system. The target phase circuit corresponds to any phase circuit in the multi-phase power grid system, and the remaining phase circuits correspond to the phase circuits in the multi-phase power grid system except the target phase circuit.

[0042] In a third aspect, the present application provides a method for determining a grid phase sequence of a power converter, the method being used in a second controller, the second controller being used to control the on / off between each single-phase power converter and a corresponding phase circuit of a multi-phase grid system, the method being used to determine the grid phase sequence corresponding to each single-phase power converter connected to the multi-phase grid system, the method comprising:

[0043] When all single-phase power converters are in a state of grid-connected power generation, receiving a first control signal sent by a first controller;

[0044] Based on the first control signal, the remaining switches are opened, so that the first controller sends a first state query request to each single-phase power converter when the target switch is closed and the remaining switches are opened, and determines the single-phase power converter whose grid phase sequence is the target phase circuit according to the first feedback information corresponding to the received first state query request;

[0045] Among them, the target switch is used to control the on and off of the single-phase power converter and the target phase circuit corresponding to the target phase circuit in the multi-phase power grid system, and the remaining switches are used to control the on and off of the single-phase power converter and the remaining phase circuits corresponding to the remaining phase circuits in the multi-phase power grid system. The target phase circuit corresponds to any one phase circuit in the multi-phase power grid system, and the remaining phase circuits correspond to the phase circuits other than the target phase circuit in the multi-phase power grid system.

[0046] In a fourth aspect, the present application provides a first controller including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the method of the first aspect and / or the second aspect are implemented.

[0047] In one embodiment, the first controller includes a switch module, and the process of the processor executing control to disconnect the remaining phase circuits in the multi-phase power grid system from the corresponding single-phase power converter includes: the processor is used to control the remaining phase circuits to disconnect from the corresponding single-phase power converter through the switch module.

[0048] In a fifth aspect, the present application provides a second controller including a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the method in the third aspect when executing the computer program.

[0049] In a sixth aspect, the present application provides a power system, comprising: a plurality of single-phase power converters, a relay and a first controller; wherein,

[0050] A first end of a target switch in a relay is connected to a controller and a target phase circuit for connecting to a multi-phase power grid system, a second end of the target switch is connected to a single-phase power converter corresponding to the target phase circuit, a first end of the remaining switches of the relay is connected to a gateway controller and the remaining phase circuits for connecting to the multi-phase power grid system, and a second end of the remaining switches is connected to the single-phase power converter corresponding to the remaining phase circuits, wherein the target phase circuit corresponds to any one phase circuit in the multi-phase power grid system, and the remaining phase circuits correspond to phase circuits other than the target phase circuit in the multi-phase power grid system;

[0051] The gateway control comprises a memory and a processor, the memory stores a computer program, and the processor implements the steps of the method of the first aspect and / or the second aspect when executing the computer program.

[0052] The grid phase sequence determination method, controller and system of the above-mentioned power converter, one aspect of the method is used in the first controller to determine the grid phase sequence corresponding to each single-phase power converter connected to the multi-phase power grid system, by controlling the remaining phase circuits and corresponding single-phase power converters in the multi-phase power grid system to be disconnected when all single-phase power converters are in the state of grid-connected power generation, sending a first status query request to each single-phase power converter, and determining the single-phase power converter whose grid phase sequence is the target phase circuit based on the first feedback information received corresponding to the first status query request, wherein the target phase circuit corresponds to any one phase circuit in the multi-phase power grid system, and the remaining phase circuits correspond to phase circuits other than the target phase circuit in the multi-phase power grid system. In this way, when all the single-phase power converters connected to the multi-phase power grid system can be normally connected to the grid for power generation, the connection between the target phase circuit and the corresponding single-phase power converter is maintained, and the connection between the remaining phase circuits and the corresponding single-phase power converter is disconnected, so that when the multi-phase power grid system is in a state where only one phase circuit is connected to the corresponding single-phase power converter and there is no power transmission in the remaining phase circuits, the working state of each single-phase power converter is actively queried, and the grid phase sequence of the single-phase power converter is determined based on the feedback information of the single-phase power converter, so as to avoid the influence of communication crosstalk between the phase circuits on the accuracy of grid phase sequence identification. The above-mentioned grid phase sequence determination method can improve the accuracy of grid phase sequence identification when the single-phase power converter is connected to the multi-phase power grid system, thereby improving the start-up efficiency of the single-phase power converter being connected to the grid. The above-mentioned grid phase sequence determination method is adopted to accurately identify the grid phase sequence of each single-phase power converter, thereby supporting the precise power control of each phase circuit and improving the power generation income of the power system. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, the drawings required for use in the embodiments or the related technical descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0054] Figure 1 An application environment diagram of a method for determining a phase sequence of a power grid in one embodiment;

[0055] Figure 2 is an application environment diagram of a method for determining a phase sequence of a power grid in another embodiment;

[0056] Figure 3 A schematic diagram of a flow chart of a method for determining a phase sequence of a power grid in one embodiment;

[0057] Figure 4 is a flow chart of a method for determining a phase sequence of a power grid in another embodiment;

[0058] Figure 5 A schematic diagram of a flow chart for determining whether all single-phase power converters are in a grid-connected power generation state in one embodiment;

[0059] Figure 6 is a flow chart of a method for determining a phase sequence of a power grid in another embodiment;

[0060] Figure 7 A schematic flow chart of a method for determining a grid phase sequence in another embodiment. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0062] The power converters involved in the embodiments of the present application are a type of power conversion equipment used to convert electrical energy from one form to another to achieve energy transmission and control under different power requirements; the power converters may be micro inverters, energy storage converters, and the like. For example, a micro inverter may convert DC power into AC power, the DC end (input) of the micro inverter is connected to a DC source (photovoltaic module), and the AC end (output) of the power converter may be connected to an AC power grid and an AC device. Among them, a single-phase power converter refers to a single-phase output or single-phase input on the AC side, and a single-phase power converter is connected to one of the phase circuits of an AC power grid or an AC device; a single-phase power converter may be a single-phase micro inverter, a single-phase energy storage converter, and the like.

[0063] In an exemplary embodiment, the power grid phase sequence determination method provided by the power converter can be applied to Figure 1 or Figure 2 Please refer to the application environment shown. Figure 1 and 2, multiple single-phase power converters are respectively connected to the first phase circuit, the second phase circuit or the third phase circuit of the three-phase power grid system. The multiple single-phase power converters can be regarded as a single-phase power converter array. The gateway controller is used as the control center of the single-phase power converter array, connected to each phase circuit and the zero-phase circuit of the three-phase power grid system, and communicates with each single-phase power converter respectively, monitors the working status of all single-phase power converters, and controls the output of each single-phase power converter to achieve precise power control of each phase circuit of the three-phase power grid system, and is used to send the device data of each single-phase power converter to the management system cooperation and cloud network management through FE (Fast Ethernet) or WLAN (Wireless Local Area Network) or 4G or 5G communication methods. In other embodiments, other types of controllers can also be connected to each single-phase power converter in communication and control the on and off of each single-phase power converter and the multi-phase power grid system.

[0064] For example, Figure 1 and Figure 2 The three lines connected to the switch represent the three live phase lines 100 of the three-phase power grid system, and the remaining line represents the zero line 200 (or neutral line) of the three-phase power grid system. The cylinder represents the wire tube 300 outside the three live phase lines 100 and the zero line 200, that is, the four phase lines are located in one cable; it should be noted that Figure 1 and 2 Each single-phase power converter shown in the figure is connected to a corresponding phase circuit during on-site wiring, but the gateway controller does not obtain the wiring relationship at this time.

[0065] exist Figure 1 In the example of the application environment shown, the gateway controller includes a processor and a switch module, wherein the processor is used to communicate with the single-phase power converter, and the switch module is used to control the connection or disconnection between each single-phase power converter and the corresponding phase circuit of the three-phase power grid system. Among them, the switch module can realize the control of the on and off of each single-phase power converter and the corresponding phase circuit respectively. Optionally, the switch module is a multi-pole multi-throw structure. It can be understood that Figure 1 The gateway controller is a gateway controller with integrated relay.

[0066] exist Figure 2 In the application environment example shown, a separate relay is provided, and the gateway controller controls the connection or disconnection between each single-phase power converter and the corresponding phase circuit of the three-phase power grid system through the relay.

[0067] The grid phase sequence in the embodiment of the present application is used to characterize which phase circuit of the first phase circuit, the second phase circuit and the third phase circuit in the three-phase grid system the single-phase power converter is connected to; during the wiring process of the single-phase power converter connected to the three-phase grid system, the grid phase sequence will not be pre-configured in the gateway controller. In the related art, when determining the grid phase sequence of the single-phase power converter, because each phase line is in the same wire tube, the physical distance between each phase line is very close, and there may be communication crosstalk between the single-phase power converters connected to each phase circuit during communication, resulting in a low accuracy of the grid phase sequence determination result. In view of this, the embodiment of the present application provides a method for determining the grid phase sequence of a power converter.

[0068] In an exemplary embodiment, the provided method for determining the grid phase sequence of a power converter can also be applied in other multi-phase grid systems such as a two-phase grid system, and is not limited to a three-phase grid system.

[0069] In an exemplary embodiment, Figure 3 As shown, a method for determining the grid phase sequence of a power converter is provided, which is used in a first controller, and the method is used to determine the grid phase sequence corresponding to each single-phase power converter connected to a multi-phase grid system. The first controller can be a gateway controller, or other controller that can communicate with each single-phase power converter and control the on and off of each single-phase power converter and the multi-phase grid system; for example, in the case where the multi-phase grid system is a three-phase grid system, the first controller can be Figure 1 or Figure 2 In this embodiment, the method includes steps 302 to 306, wherein:

[0070] Step 302: When all the single-phase power converters are in a state of grid-connected power generation, control the remaining phase circuits in the multi-phase power grid system to be disconnected from the corresponding single-phase power converters.

[0071] In this embodiment, although the first controller cannot determine the grid phase sequence of each single-phase power converter, it can determine the total number of single-phase power converters in the multi-phase grid system.

[0072] Among them, after the first controller is started, all single-phase power converters are controlled to be connected to the corresponding phase circuits, that is, each phase circuit is controlled to be connected to the corresponding single-phase power converter to determine whether each single-phase power converter can work normally. After determining that all single-phase power converters are in the state of grid-connected power generation, the grid phase sequence of the single-phase power converter is determined to avoid the failure of a single-phase power converter, which leads to inaccurate determination of the grid phase sequence of the overall single-phase power converter.

[0073] In this embodiment, each phase circuit in the multi-phase power grid system is divided into a target phase circuit and other phase circuits, wherein the target phase circuit corresponds to any phase circuit in the multi-phase power grid system, and the other phase circuits correspond to phase circuits in the multi-phase power grid system except the target phase circuit.

[0074] In a possible implementation, the multi-phase power grid system is a three-phase power grid system, and the three-phase power grid system includes a first phase circuit, a second phase circuit, and a third phase circuit; the target phase circuit may be the first phase circuit, and the remaining circuits may be the second phase circuit and the third phase circuit. In this implementation, after the first controller is started, the first phase circuit, the second phase circuit, and the third phase circuit are controlled to be connected to the corresponding single-phase power converter to determine whether each single-phase power converter can work normally.

[0075] In a possible implementation, the multi-phase power grid system is a two-phase power grid system; the two-phase power grid system includes a first phase circuit and a second phase circuit, the target phase circuit may be the first phase circuit, and the remaining phase circuits may be the second phase circuit. In this implementation, after the first controller is started, the first phase circuit and the second phase circuit are controlled to be connected to the corresponding single-phase power converters to determine whether each single-phase power converter can work normally.

[0076] Among them, the remaining phase circuits are controlled to be disconnected from the corresponding single-phase power converters, so that the single-phase power converters corresponding to the remaining phase circuits change from a power generation state to a non-power generation state. At this time, only the single-phase power converter corresponding to the target phase circuit is in a power generation state, which can avoid power transmission on the remaining phase circuits and cause crosstalk to the communication between the single-phase power converter connected to the target phase circuit and the first controller.

[0077] Exemplarily, being in a non-power generating state includes being in a standby state or in a fault state.

[0078] In one possible implementation, the processor in the first controller controls all single-phase power converters to be connected to corresponding phase circuits through a switch module; after determining that all single-phase power converters are in a state of grid-connected power generation, the processor controls the remaining phase circuits in the multi-phase power grid system to be disconnected from the corresponding single-phase power converters through the switch module.

[0079] Step 304: Send a first status query request to each single-phase power converter.

[0080] Among them, the state query request is used for the single-phase power converter to feedback the current working state of the device based on the state query request; the first state query request refers to the state query request sent by the first controller to all single-phase power converters. Optionally, the current working state of the single-phase power converter may include a state identification code maintained by the single-phase power converter based on its own working state. For example, the state identification code is "00" indicating that the single-phase power converter is currently in a standby state, the state identification code is "01" indicating that the single-phase power converter is currently in a working state, and the state identification code is "11" indicating that the single-phase power converter is currently in a fault state. Optionally, the current working state of the single-phase power converter may include the current power generation power of the single-phase power converter. For example, when the single-phase power converter is connected to the corresponding phase circuit in the multi-phase power grid system, the power generation power is 5500 watts (W), and when the single-phase power converter is disconnected from the corresponding phase circuit in the multi-phase power grid system, the power generation power is 0W.

[0081] In a possible implementation manner, the first controller broadcasts the first status query request to all single-phase power converters in a broadcasting manner.

[0082] Step 306: Determine, based on the received first feedback information corresponding to the first status query request, that the grid phase sequence is a single-phase power converter of a target phase circuit.

[0083] Among them, the first feedback information refers to the feedback information made by the single-phase power converter based on the first state query request, including the current working state of the single-phase power converter. Exemplarily, when the single-phase power converter is in a power generation state, the feedback information includes a state identification code corresponding to the working state, and when the single-phase power converter is in a non-power generation state, the feedback information includes a state identification code corresponding to the standby state or the fault state. Optionally, the feedback information may also include the current power generation power of the single-phase power converter. It can be understood that the power generation power in the feedback information is 0 when the single-phase power converter is in a standby state or a fault state.

[0084] When the target phase circuit is connected to the corresponding single-phase power converter and the remaining phase circuits are disconnected from the corresponding single-phase power converters, only the single-phase power converter connected to the target phase circuit is in the power generation state, that is, it is in the working state and has power generation power; the single-phase power converter connected to the remaining phase circuits will not reply to the first status query request, that is, it will not send the first feedback information, or the current working state included in the first feedback information replied by the single-phase power converter connected to the remaining phase circuits is a non-working state; therefore, the first controller can identify the single-phase power converter connected to the target phase circuit based on the received first feedback information, and determine the grid phase sequence of these single-phase power converters connected to the target phase circuit as the target phase circuit.

[0085] In the first possible implementation of the present embodiment, after identifying the single-phase power converter connected to the target phase circuit, the first controller controls the remaining phase circuits to be connected to the corresponding single-phase power converter, re-determines one phase circuit from the remaining phase circuits as the current target phase circuit, and then determines the phase circuits other than the current target phase circuit as the remaining phase circuits, and re-executes "when all the single-phase power converters are in the state of grid-connected power generation, controls the remaining phase circuits in the multi-phase power grid system to be disconnected from the corresponding single-phase power converter; sends a first status query request to each of the single-phase power converters; determines the single-phase power converter whose grid phase sequence is the target phase circuit based on the first feedback information received corresponding to the first status query request", and repeats the above process until all phase circuits in the multi-phase power grid system are used as target phase circuits, and the grid phase sequence corresponding to the corresponding single-phase power converter is determined.

[0086] It can be understood that in the above-mentioned first embodiment, the first controller is equivalent to repeating the steps shown in steps 302 to 306 for multiple times, changing the phase circuit that is currently in a connected state during each execution, and shutting down the remaining phase circuits, and sending a first status query request to all single-phase power converters during each execution to identify the single-phase power converters corresponding to the remaining phase circuits.

[0087] In the first application scenario of the first embodiment described above, the multi-phase power grid system is a three-phase power grid system, and the three-phase power grid system includes a first-phase circuit, a second-phase circuit and a third-phase circuit. During the first identification, the second-phase circuit and the third-phase circuit are controlled to be disconnected from the corresponding single-phase power converter, and the single-phase power converter whose grid phase sequence is the first-phase circuit is identified. During the second identification, the second-phase circuit and the third-phase circuit are controlled to be connected to the corresponding single-phase power converter. When all the single-phase power converters are in a state of grid-connected power generation, the first-phase circuit and the third-phase circuit are controlled to be disconnected from the corresponding single-phase power converter; each of the single-phase power converters is connected to the grid. The power converter sends a first status query request; according to the received first feedback information corresponding to the first status query request, the single-phase power converter whose phase sequence of the power grid is the second phase circuit is determined; then, the first phase circuit and the third phase circuit are controlled to be linked with the corresponding single-phase power converter, and when all the single-phase power converters are in the state of grid-connected power generation, the first phase circuit and the second phase circuit are controlled to be disconnected from the corresponding single-phase power converter, and a first status query request is sent to each single-phase power converter, and according to the received first feedback information corresponding to the first status query request, the single-phase power converter whose phase sequence of the power grid is the third phase circuit is determined.

[0088] In the second application scenario of the first embodiment mentioned above, the multi-phase power grid system is a two-phase power grid system, and the two-phase power grid system includes a first phase circuit and a second phase circuit. After identifying the single-phase power converter connected to the first phase circuit, the second phase circuit is controlled to be connected to the corresponding single-phase power converter. When all the single-phase power converters are in the state of grid-connected power generation, the first phase circuit is controlled to be disconnected from the corresponding single-phase power converter; a first status query request is sent to each of the single-phase power converters; and based on the received first feedback information corresponding to the first status query request, the grid phase sequence is determined to be the single-phase power converter of the second phase circuit.

[0089] In other application scenarios of the first embodiment mentioned above, the multi-phase power grid system can correspond to a multi-phase power grid system other than a two-phase power grid system or a three-phase power grid system. The specific implementation process can refer to the implementation method of the three-phase power grid system or the two-phase power grid system, which will not be repeated here.

[0090] In a second possible implementation of this embodiment, after identifying the single-phase power converter connected to the target phase circuit, in the process of identifying the single-phase power converters connected to the remaining phase circuits, subsequent status query requests are no longer sent to the single-phase power converters whose grid phase sequence has been determined, so as to improve the identification efficiency.

[0091] In a first application scenario of the second implementation mode, the multi-phase power grid system is a three-phase power grid system, and the three-phase power grid system includes a first phase circuit, a second phase circuit and a third phase circuit. In steps 302 to 306, the target phase circuit includes the first phase circuit, and the remaining phase circuits include the second phase circuit and the third phase circuit. The process of controlling the remaining phase circuits in the multi-phase power grid system to be disconnected from the corresponding single-phase power converters in step 302 includes: controlling the second phase circuit and the third phase circuit to be disconnected from the corresponding single-phase power converters; in step 306, the process of determining that the power grid phase sequence is a single-phase power converter of the target phase circuit according to the received first feedback information corresponding to the first status query request includes: determining that the power grid phase sequence is a single-phase power converter of the first phase circuit according to the first feedback information; in this example, after step 306, according to Figure 4 Steps 402 to 408 shown determine the grid phase sequence as a single-phase power converter of the second phase circuit:

[0092] Step 402: Control the second phase circuit and the third phase circuit to be connected to corresponding single-phase power converters.

[0093] Step 404: when all the single-phase power converters are in a state of grid-connected power generation, the first phase circuit and the third phase circuit are controlled to be disconnected from the corresponding single-phase power converters.

[0094] Step 406: Send a second status query request to each single-phase power converter whose grid phase sequence is not the first phase circuit.

[0095] Among them, the second status query request means that the recipients of the request only include the single-phase power converters whose grid phase sequence is not the first phase circuit. The difference from the "first status query request" in step 304 is that the recipients of the request are not all the same. The recipients of the first status query request include all single-phase power converters controlled by the gateway controller, and the recipients of the second status query request do not include the single-phase power converter whose grid phase sequence has been determined as the first phase circuit.

[0096] Step 408: Determine, based on the received second feedback information corresponding to the second state query request, that the grid phase sequence is a single-phase power converter of a second phase circuit.

[0097] The second feedback information refers to feedback information made by the single-phase power converter based on the second state query request.

[0098] In the first application scenario of the second embodiment described above, after determining that the grid phase sequence is a single-phase power converter of the second phase circuit, the following can be used: Figure 4 The implementation shown in steps 410 to 416 is to determine a single-phase power converter whose grid phase sequence is the third phase, wherein steps 410 to 416 include:

[0099] Step 410: Control the first phase circuit and the third phase circuit to be connected to corresponding single-phase power converters.

[0100] Step 412: When all the single-phase power converters are in a state of grid-connected power generation, the first phase circuit and the second phase circuit are controlled to be disconnected from the corresponding single-phase power converters.

[0101] Step 414: Send a third status query request to each single-phase power converter whose grid phase sequence is neither the first phase circuit nor the second phase circuit.

[0102] Among them, the third status query request means that the recipients of the request only include single-phase power converters whose grid phase sequence is not the first phase and the second phase. The difference from the first status query request and the second status query request is that the recipients are not all the same.

[0103] Step 416: Determine, based on the received third feedback information corresponding to the third state query request, that the grid phase sequence is a single-phase power converter of a third phase circuit.

[0104] In the first application scenario of the second embodiment mentioned above, after determining that the grid phase sequence is a single-phase power converter of the second phase circuit, the grid phase sequence of the single-phase power converter whose grid phase sequence is neither the first phase circuit nor the second phase circuit can be directly determined as a third phase circuit; in this way, based on the single-phase power converter corresponding to the two-phase circuit that has been determined, the single-phase power converter corresponding to the remaining one-phase circuit is directly determined, thereby improving the efficiency of determining the grid phase sequence.

[0105] In a second application scenario of the second embodiment, the multi-phase power grid system is a two-phase power grid system, and the two-phase power grid system includes a first phase circuit and a second phase circuit; exemplarily, after identifying the single-phase power converter connected to the first phase circuit, the second phase circuit can be controlled to be connected to the corresponding single-phase power converter, and when all the single-phase power converters are in a state of grid-connected power generation, the first phase circuit is controlled to be disconnected from the corresponding single-phase power converter, and a second state query request is sent to each single-phase power converter whose grid phase sequence is not the first phase circuit, and the single-phase power converter whose grid phase sequence is the second phase circuit is determined according to the second feedback information corresponding to the second state query request received; exemplarily, after identifying the single-phase power converter connected to the first phase circuit, the grid phase sequence of the single-phase power converter whose grid phase sequence is not the first phase circuit can be directly determined as the second phase circuit; in this way, based on the single-phase power converter corresponding to the determined first phase circuit, the single-phase power converter corresponding to the remaining one phase circuit is directly determined, thereby improving the efficiency of determining the grid phase sequence.

[0106] In other application scenarios of the above-mentioned second embodiment, the multi-phase power grid system can correspond to a multi-phase power grid system other than a two-phase power grid system or a three-phase power grid system. The specific implementation process can refer to the implementation method of the three-phase power grid system or the two-phase power grid system, which will not be repeated here.

[0107] After the grid phase sequence identification of all single-phase power converters is completed, each phase circuit in the multi-phase grid system is controlled to be connected to the corresponding single-phase power converter, so that all single-phase power converters generate electricity normally.

[0108] The grid phase sequence determination method of the power converter provided in the above embodiment is used in a first controller, and the method is used to determine the grid phase sequence corresponding to each single-phase power converter connected to the multi-phase power grid system by controlling the remaining phase circuits and the corresponding single-phase power converters in the multi-phase power grid system to be disconnected when all single-phase power converters are in a grid-connected power generation state, sending a first status query request to each single-phase power converter, and determining the single-phase power converter whose grid phase sequence is the target phase circuit based on the first feedback information received corresponding to the first status query request, wherein the target phase circuit corresponds to any one phase circuit in the multi-phase power grid system, and the remaining phase circuits correspond to phase circuits other than the target phase circuit in the multi-phase power grid system. In this way, when all the single-phase power converters connected to the multi-phase power grid system can be normally connected to the grid for power generation, the connection between the target phase circuit and the corresponding single-phase power converter is maintained, and the connection between the remaining phase circuits and the corresponding single-phase power converter is disconnected, so that when the multi-phase power grid system is in a state where only one phase circuit is connected to the corresponding single-phase power converter and there is no power transmission in the remaining phase circuits, the working state of each single-phase power converter is actively queried, and the grid phase sequence of the single-phase power converter is determined based on the feedback information of the single-phase power converter, so as to avoid the influence of communication crosstalk between the phase circuits on the accuracy of grid phase sequence identification. The grid phase sequence determination method provided by the above embodiment can improve the accuracy of grid phase sequence identification when the single-phase power converter is connected to the multi-phase power grid system, thereby improving the start-up efficiency of the single-phase power converter connected to the grid. The grid phase sequence determination method provided by the above embodiment is used to accurately identify the grid phase sequence of each single-phase power converter, thereby supporting the precise power control of each phase circuit and improving the power generation income of the power system.

[0109] In an exemplary embodiment, the communication method between the first controller and each single-phase power converter includes a wireless communication method or a power line communication method (PowerLine Communication, PLC for short). In this embodiment, according to the received first feedback information corresponding to the first state query request, the process of determining the single-phase power converter whose power grid phase sequence is the target phase circuit includes: determining the power grid phase sequence of the single-phase power converter whose first feedback information includes the first state information as the target phase circuit; determining the power grid phase sequence of the single-phase power converter whose first feedback information includes the second state information as not being the target phase circuit, wherein the first state information is used to indicate that the corresponding single-phase power converter is in a working state, and the second state information is used to indicate that the corresponding single-phase power converter is not in a working state.

[0110] Optionally, the first state information includes that the working state parameter of the single-phase power converter is "in working state", and the working state identification code is exemplarily "01". The second state information includes that the working state parameter of the single-phase power converter is "in standby state" or "in fault state", and the working state identification code is exemplarily "10" or "11".

[0111] Optionally, the first state information includes that the power generation power of the single-phase power converter is greater than 0; and the second state information includes that the power generation power of the single-phase power converter is 0.

[0112] Optionally, or, the first state information includes that the power generation power of the single-phase power converter is greater than a first threshold and less than a second threshold; the second state information includes that the power generation power of the single-phase power converter is between the first threshold and the second threshold, wherein the range from the first threshold to the second threshold is the normal power generation power range of the single-phase power converter.

[0113] In the case where the communication mode between the controller and each single-phase power converter is wireless communication, when the remaining phase circuits are disconnected from the corresponding single-phase power converters, the single-phase power converters connected to the remaining phase circuits are not in the power generation state, but can reply to the first feedback information through wireless communication, that is, all single-phase power converters will reply to the first feedback information to the first controller; the first controller determines the single-phase power converter in the working state according to the content included in the first feedback information, and determines the single-phase power converter with the grid phase sequence as the target phase. If the first feedback information includes the first state information, it means that the single-phase power converter is in the working state, and the grid phase sequence of the single-phase power converter is marked as the target phase circuit; if the first feedback information includes the second state information, it means that the single-phase power converter is not in the working state, and the grid phase sequence of the single-phase power converter is determined as not being the target phase circuit.

[0114] When the communication mode between the first controller and each single-phase power converter is PLC, when the remaining phase circuits are disconnected from the corresponding single-phase power converters, the communication connection between the single-phase power converters connected to the remaining phase circuits and the first controller is also disconnected. In theory, the single-phase power converters connected to the remaining phase circuits will not receive the first status query request nor reply to the first status query request. Figure 1 and Figure 2As shown, multiple live phase lines and neutral lines connecting each single-phase power converter are generally located in the same wire tube. When PLC is used, although there is no power transmission in the remaining phase circuits disconnected from the single-phase power converter, only one phase circuit has power transmission. However, because the distance between the phase lines is very close, the target phase circuit with power transmission will generate PLC crosstalk to the remaining phase circuits, causing some single-phase power converters connected to the target phase circuit to reply to the first status query request. In this embodiment, the grid-connected phase sequence of the single-phase power converter whose first feedback information includes the first status information but not the second status information is determined as the target phase circuit. Since the characteristics of the first status information and the second status information are not exactly the same, the first feedback information can be distinguished based on this, thereby screening out the first feedback information that crosstalks to the target phase circuit, excluding the corresponding single-phase power converter, and avoiding the influence of PLC crosstalk on the accuracy of grid phase sequence determination.

[0115] In an exemplary embodiment, the communication method between the first controller and each single-phase power converter includes a one-to-one wired communication method. Exemplarily, the one-to-one wired communication method includes an RS 485 (Recommended Standard 485) communication method. In this embodiment, according to the received first feedback information corresponding to the first status query request, the process of determining the grid phase sequence of the single-phase power converter of the target phase circuit includes: determining the grid phase sequence of the single-phase power converter that feeds back the first feedback information as the target phase circuit.

[0116] In this embodiment, a one-to-one wired communication method is used between the first controller and each single-phase power converter. When the single-phase power converters corresponding to the remaining phase circuits are disconnected, the communication connection between the single-phase power converters connected to the remaining phase circuits and the controller is also disconnected, and the single-phase power converters connected to the remaining phase circuits will not receive the first status query request or reply to the first status query request; therefore, in this embodiment, the single-phase power converters whose grid phase sequence is the target phase circuit can be directly determined based on which single-phase power converters have fed back the first feedback information.

[0117] In an exemplary embodiment, please refer to Figure 5 In the power grid phase sequence determination method provided by the power converter, it is determined whether all single-phase power converters are in a state of grid-connected power generation according to the process shown in steps 502 to 506, wherein:

[0118] Step 502: Send a fourth status query request to all single-phase power converters.

[0119] After all phase circuits are controlled to be connected to the corresponding single-phase power converters, a fourth state query request is sent to all single-phase power converters to obtain the current working state of each single-phase power converter.

[0120] Exemplarily, the request content of the fourth status query request is the same as the first status query request, the second status query request, and the third status query request.

[0121] Step 504: if the first number is equal to the second number, it is determined that all single-phase power converters are in a state of grid-connected power generation.

[0122] The first number is the number of fourth feedback information corresponding to the fourth status query request received within a preset time period, and the second number is the number of single-phase power converters connected to the multi-phase power grid system.

[0123] In one possible implementation, within a preset time period, the first controller sends a fourth status query request to each single-phase power converter according to a preset query frequency until the preset time period ends or all single-phase power converters reply with fourth feedback information, so as to improve the efficiency of obtaining the working status of all single-phase power converters.

[0124] In one possible implementation, the first controller sends a fourth state query request to each single-phase power converter, and counts the number of single-phase power converters that respond to the fourth state query request within a preset time period; if some single-phase power converters respond to the fourth state query request after the preset time period, it is considered that the single-phase power converter is not in a grid-connected power generation state and is not counted.

[0125] Step 506: If the first number is not equal to the second number, it is determined that not all single-phase power converters are in a state of grid-connected power generation.

[0126] Among them, when the first number is not equal to the second number, some single-phase power converters may have a power generation function failure, or there may be a communication failure between some single-phase power converters and the gateway controller, or there may be other principles; therefore, when the first number is not equal to the second number, it is determined that not all single-phase power converters are in a state of grid-connected power generation, and the subsequent grid phase sequence determination method is not executed to avoid inaccurate identification.

[0127] In an exemplary embodiment, please refer to Figure 6 , provides a method for determining the grid phase sequence of a power converter, the method is used in a first controller, the first controller is communicatively connected to a second controller, the second controller is used to control the on-off between each single-phase power converter and the corresponding phase circuit of the multi-phase grid system, the method is used to determine the grid phase sequence corresponding to each single-phase power converter connected to the multi-phase grid system; wherein the first controller and the second controller are independent of each other; wherein the first controller may be Figure 2 The gateway controller shown in the figure, the second controller can be Figure 2The switch controller in the relay shown in FIG. 1 is a switch controller in the relay shown in FIG. 2 ; it can be understood that the first controller can also be other controllers that can communicate with each single-phase power converter and control the on / off of each single-phase power converter and the multi-phase power grid system through an external switch. Figure 6 As shown, the method includes steps 602 to 606.

[0128] Step 602: When all single-phase power converters are in a state of grid-connected power generation, a first control signal is sent to a second controller, wherein the first control signal is used for the second controller to execute opening of the remaining switches.

[0129] In this embodiment, each phase circuit in the multi-phase power grid system is divided into a target phase circuit and other phase circuits, wherein the target phase circuit corresponds to any one phase circuit in the multi-phase power grid system, and the other phase circuits correspond to the phase circuits other than the target phase circuit in the multi-phase power grid system; the other switches are used to control the on-off of the single-phase power converter and the other phase circuits corresponding to the other phase circuits in the multi-phase power grid system. Correspondingly, in this embodiment, the on-off of the single-phase power converter and the first phase circuit corresponding to the target phase circuit in the multi-phase power grid system is achieved by controlling the target switch.

[0130] In a possible implementation, the multi-phase power grid system is a three-phase power grid system, the target switch includes a first switch, and the remaining switches include a second switch and a third switch; the first control signal is used for the second controller to execute at least one action of opening the second switch or opening the third switch.

[0131] In one example of the above implementation, Figure 2 As shown, the first switch, the second switch, the third switch and the switch controller are arranged inside the relay, and the switch controller can be a processor inside the relay; the gateway controller controls the connection and disconnection between the corresponding phase circuit and each single-phase power converter through the relay; the first end of the first switch of the relay is connected to the gateway controller and the first phase circuit, the second end of the first switch is connected to the single-phase power converter corresponding to the first phase circuit, the first end of the second switch in the relay is connected to the gateway controller and the second phase circuit, the second end of the second switch is connected to the single-phase power converter corresponding to the second phase circuit, the first end of the third switch in the relay is connected to the gateway controller and the third phase circuit, and the second end of the third switch is connected to the single-phase power converter corresponding to the third phase circuit; the switch controller is used to control the on and off of the first switch, the second switch and the third switch; in this embodiment, when the switch controller receives the first control signal, it turns on the second switch and the third switch.

[0132] Optionally, the first switch, the second switch and the third switch are the first contact, the second contact and the third contact in the multi-pole multi-throw structure inside the relay, and each contact is equivalent to a switch, which controls the on-off of the circuit between the corresponding phase circuit and the single-phase power converter.

[0133] In another example of the above-mentioned embodiment, the multi-phase power grid system is a three-phase power grid system, the target switch includes a first switch, and the remaining switches include a second switch and a third switch; the first switch, the second switch and the third switch each correspond to a switch controller; each switch controller is connected to a gateway controller respectively; the switch controller corresponding to the first switch keeps the first switch in a closed state when receiving a first control signal, the switch controller corresponding to the second switch opens the second switch when receiving the first control signal, and the switch controller corresponding to the third switch opens the third switch when receiving the first control signal.

[0134] Step 604: Send a first status query request to each single-phase power converter.

[0135] Step 606: Determine, based on the received first feedback information corresponding to the first status query request, that the grid phase sequence is a single-phase power converter of a target phase circuit.

[0136] Among them, after the first controller determines that the grid phase sequence is the single-phase power converter of the target phase circuit, it sends a control signal to the second controller to close the switches between all phase circuits and the corresponding single-phase power converters, or sends a control signal to the second controller to close the remaining switches, so that all single-phase power converters can be in a state of grid-connected power generation; and then executes the subsequent determination of the single-phase power converters corresponding to other grid phase sequences.

[0137] In a possible implementation, the multi-phase power grid system is a three-phase power grid system. After determining that the power grid phase sequence is a single-phase power converter of a first phase circuit, the first controller sends a control signal to close the switch between all phase circuits and the corresponding single-phase power converter to the second controller, or sends a control signal to close the second switch and the third switch to the second controller, so that all single-phase power converters can be in a state of grid-connected power generation, and then sends a second control signal to the second controller to determine that the power grid phase sequence is a single-phase power converter of a second phase circuit, wherein the second control signal is used for the second controller to execute opening the first switch and opening the third switch. At least one action in the switch; thereafter, after determining that the grid phase sequence is the single-phase power converter of the second phase circuit, the first controller sends a control signal to close the switches between all phase circuits and the corresponding single-phase power converters to the second controller, or sends a control signal to close the first switch and the third switch to the second controller, so that all single-phase power converters can be in a state of grid-connected power generation, and then sends a third control signal to the second controller to determine that the grid phase sequence is the single-phase power converter of the target phase circuit, wherein the third control signal is used for the second controller to perform at least one action of opening the second switch or opening the first switch.

[0138] Optionally, the second control signal and the third control signal are preconfigured. Optionally, the second control signal is obtained by modifying the first control signal after the first controller identifies that the grid phase sequence is a single-phase power converter of the first phase circuit, and the third control signal is obtained by modifying the second control signal after the first controller identifies that the grid phase sequence is a single-phase power converter of the second phase circuit.

[0139] The present embodiment provides a method for determining a grid phase sequence, wherein a first controller is connected to a second controller, the second controller is used to control the on / off of each single-phase power converter and a corresponding phase circuit of a multi-phase grid system, the first controller sends a relevant control signal to the second controller, so that the second controller controls one phase circuit in the multi-phase grid system to be connected to the corresponding single-phase power converter, and the remaining phase circuits are disconnected from the corresponding single-phase power converter, the first controller actively queries the working status of each single-phase power converter, determines to connect the single-phase power converter that is currently in a connected state based on the feedback of the single-phase power converter, and then identifies the grid phase sequence corresponding to each single-phase power converter, thereby improving the accuracy of the grid phase sequence determination and improving the start-up efficiency of the single-phase power converter connected to the grid.

[0140] In an exemplary embodiment, please refer to Figure 7 , provides a method for determining the phase sequence of a power grid of a power converter, and takes the method applied to a second controller as an example for explanation, the second controller is used to control the on-off between each single-phase power converter and the corresponding phase circuit of the multi-phase power grid system. Figure 7 As shown, the method for determining the phase sequence of a power grid provided in this embodiment includes step 702 and step 704 .

[0141] Step 702: When all single-phase power converters are in a state of grid-connected power generation, a first control signal sent by a first controller is received.

[0142] Step 704, based on the first control signal, executes opening of the remaining switches, so that the first controller sends a first status query request to each single-phase power converter when the target switch is closed and the remaining switches are opened, and determines the single-phase power converter whose grid phase sequence is the target phase circuit based on the first feedback information corresponding to the received first status query request.

[0143] Among them, the target switch is used to control the on and off of the single-phase power converter and the target phase circuit corresponding to the target phase circuit in the multi-phase power grid system, and the remaining switches are used to control the on and off of the single-phase power converter and the remaining phase circuits corresponding to the remaining phase circuits in the multi-phase power grid system; the target phase circuit corresponds to any one phase circuit in the multi-phase power grid system, and the remaining phase circuits correspond to the phase circuits in the multi-phase power grid system except the target phase circuit.

[0144] In a possible implementation, the multi-phase power grid system is a three-phase power grid system, the target phase circuit in step 702 and step 704 corresponds to the first phase circuit, the target switch corresponds to the first switch, the remaining phase circuits correspond to the second phase circuit and the third phase circuit, and the remaining switches correspond to the second switch and the third switch. The process of opening the remaining switches based on the first control signal in step 704 includes: executing at least one action of opening the second switch or the third switch based on the first control signal; in this implementation, after the first controller determines that the grid phase sequence is a single-phase power converter of the first phase circuit, the second controller receives a control signal sent by the first controller to close the switch between all phase circuits and the corresponding single-phase power converter, or receives a control signal sent by the first controller to close the second switch and the third switch, and after executing the corresponding control signal, all switches are in a closed state; after the first controller determines that all single-phase power converters are in a state of grid-connected power generation, A second control signal is received from the first controller, and based on the second control signal, at least one of the actions of opening the first switch and opening the third switch is performed, so that the first controller determines that the grid phase sequence is a single-phase power converter of the second phase circuit; after the first controller determines that the grid phase sequence is a single-phase power converter of the second phase circuit, the second controller receives a control signal sent by the first controller to close the switches between all phase circuits and the corresponding single-phase power converters, or receives a control signal sent by the first controller to close the first switch and close the second switch, and after executing the corresponding control signal, all switches are in a closed state; after the first controller determines that all single-phase power converter ports are in a state of grid-connected power generation, the second controller receives a third control signal sent by the first controller, and based on the third control signal, at least one of the actions of opening the second switch or opening the first switch is performed, so that the first controller determines that the grid phase sequence is a single-phase power converter of the third phase circuit.

[0145] The grid phase sequence determination method of the power converter provided in this embodiment is applied to the second controller. The second controller serves as an on-off control device between each single-phase power converter and the corresponding phase circuit of the multi-phase power grid system. It receives the relevant control signal of the first controller, controls one of the phase circuits in the multi-phase power grid system to be connected to the corresponding single-phase power converter, and disconnects the remaining phase circuits from the corresponding single-phase power converter, so that the first controller can query the working status of each single-phase power converter in this on-off state, and then determine the grid phase sequence of each single-phase power converter, thereby improving the accuracy of the grid phase sequence determination and improving the start-up efficiency of the single-phase power converter connected to the grid.

[0146] In an exemplary embodiment, the second controller and each switch are arranged in a relay. In an embodiment in which the multi-phase power grid system is a three-phase power grid system, Figure 2As shown, a first switch, a second switch, a third switch and a switch controller are arranged in a relay, and the first controller is a gateway controller; wherein, a first end of the first switch is connected to the gateway controller and a first phase circuit of a three-phase power grid system, a second end of the first switch is connected to a single-phase power converter corresponding to the first phase circuit, a first end of the second switch is connected to the gateway controller and a second phase circuit of the three-phase power grid system, a second end of the second switch is connected to a single-phase power converter corresponding to the second phase circuit, a first end of the third switch is connected to the gateway controller and a third phase circuit of the three-phase power grid system, and a second end of the third switch is connected to a single-phase power converter corresponding to the third phase circuit.

[0147] In this embodiment, the process of opening the remaining switches based on the first control signal includes: opening the second switch and the third switch based on the first control signal.

[0148] It should be understood that, although the steps in the flowcharts involved in the above embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above embodiments may include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0149] It is understood that the term "based on" used in this application is used to describe one or more factors that affect the determination, and does not exclude other factors that may affect the determination. For example, the phrase "determine A based on B" means that the determination of A can be based entirely or at least partially on factor B, that is, B is a factor that affects the determination of A, but does not exclude that the determination of A is also based on C.

[0150] Based on the same inventive concept, the embodiment of the present application also provides a power grid phase sequence determination device for implementing the power grid phase sequence determination method of the power converter involved above. The implementation scheme for solving the problem provided by the device is similar to the implementation scheme recorded in the above method, so the specific limitations in the embodiments of the power grid phase sequence determination device for one or more power converters provided below can refer to the limitations of the power grid phase sequence determination method for the power converter above, and will not be repeated here.

[0151] In an exemplary embodiment, a power grid phase sequence determination device for a power converter is provided, which is used in a first controller to identify the power grid phase sequence corresponding to each single-phase power converter connected to a multi-phase power grid system. The power grid phase sequence determination device includes: an on-off control module, a state query module and a phase sequence determination module, wherein:

[0152] The on-off control module is used to control the remaining phase circuits in the multi-phase power grid system to be disconnected from the corresponding single-phase power converters when all single-phase power converters are in the state of grid-connected power generation;

[0153] A state query module, used for sending a first state query request to each single-phase power converter;

[0154] A phase sequence determination module, configured to determine, based on the received first feedback information corresponding to the first state query request, that the grid phase sequence is a single-phase power converter of a target phase circuit;

[0155] The target phase circuit corresponds to any phase circuit in the multi-phase power grid system, and the remaining phase circuits correspond to phase circuits other than the target phase circuit in the multi-phase power grid system.

[0156] In an exemplary embodiment, the communication method between the controller and each single-phase power converter includes a wireless communication method or a power carrier communication method; the phase sequence determination module is used to determine the grid phase sequence of the single-phase power converter whose first feedback information includes first state information as a target phase circuit, and the first state information is used to indicate that the corresponding single-phase power converter is in a working state; the grid phase sequence of the single-phase power converter whose first feedback information includes second state information is determined as not being a target phase circuit, and the second state information is used to indicate that the corresponding single-phase power converter is not in a working state.

[0157] In an exemplary embodiment, the communication mode between the controller and each single-phase power converter includes a one-to-one wired communication mode; the phase sequence determination module is used to determine the grid phase sequence of the single-phase power converter that feeds back the first feedback information as the target phase circuit.

[0158] In an exemplary embodiment, the multi-phase power grid system is a three-phase power grid system, the target phase circuit includes a first phase circuit, and the remaining phase circuits include a second phase circuit and a third phase circuit; the on-off control module is used to control the second phase circuit and the third phase circuit to be disconnected from the corresponding single-phase power converter; the phase sequence determination module is used to determine that the grid phase sequence is the single-phase power converter of the first phase circuit based on the first feedback information.

[0159] In an exemplary embodiment, the on-off control module is also used to control the second phase circuit and the third phase circuit to be connected to the corresponding single-phase power converter; when all single-phase power converters are in the state of grid-connected power generation, the first phase circuit and the third phase circuit are controlled to be disconnected from the corresponding single-phase power converter; the state query module is also used to send a second state query request to each single-phase power converter whose grid phase sequence is not the first phase circuit; the phase sequence determination module is also used to determine the single-phase power converter whose phase sequence is the second phase circuit based on the second feedback information received corresponding to the second state query request.

[0160] In an exemplary embodiment, the on-off control module is also used to control the first phase circuit and the third phase circuit to be connected to the corresponding single-phase power converters; when all single-phase power converters are in a state of grid-connected power generation, the first phase circuit and the second phase circuit are controlled to be disconnected from the corresponding single-phase power converters; the state query module is also used to send a third state query request to each single-phase power converter whose grid phase sequence is not the first phase circuit and the second phase circuit; the phase sequence determination module is also used to determine the single-phase power converter whose phase sequence is the third phase circuit based on the third feedback information received corresponding to the third state query request.

[0161] In an exemplary embodiment, the grid phase sequence determination module is further configured to determine the grid phase sequence of the single-phase power converter whose grid phase sequence is not the first phase circuit and the second phase circuit as the third phase circuit.

[0162] In an exemplary embodiment, the status query module is also used to send a fourth status query request to all single-phase power converters. If the first number is equal to the second number, it is determined that all single-phase power converters are in a state of grid-connected power generation; the first number is the number of fourth feedback information corresponding to the fourth status query request received within a preset time length, and the second number is the number of single-phase power converters connected to the three-phase power grid system; if the first number is not equal to the second number, it is determined that not all single-phase power converters are in a state of grid-connected power generation.

[0163] In an exemplary embodiment, a power grid phase sequence determination device for a power converter is provided, which is used in a first controller, the first controller is connected to a second controller, and the second controller is used to control the on-off between each single-phase power converter and the corresponding phase circuit of the multi-phase power grid system; the power grid phase sequence determination device is used to determine the power grid phase sequence of each single-phase power converter connected to the three-phase power grid system. The power grid phase sequence determination device includes: an on-off control module, a state query module and a phase sequence determination module, wherein:

[0164] The on-off control module is used to send a first control signal to the second controller when all single-phase power converters are in a state of grid-connected power generation, and the first control signal is used for the second controller to execute opening of the remaining switches;

[0165] A state query module, used for sending a first state query request to each single-phase power converter;

[0166] A phase sequence determination module, configured to determine, based on the received first feedback information corresponding to the first state query request, that the grid phase sequence is a single-phase power converter of a target phase circuit;

[0167] Among them, the remaining switches are used to control the on and off of the single-phase power converters and the remaining phase circuits corresponding to the remaining phase circuits in the three-phase power grid system. The target phase circuit corresponds to any phase circuit in the multi-phase power grid system, and the remaining phase circuits correspond to the phase circuits in the multi-phase power grid system except the target phase circuit.

[0168] In an exemplary embodiment, a power converter grid phase sequence determination device is provided, which is used in a second controller. The device is used to determine the grid phase sequence of each single-phase power converter connected to a multi-phase grid system, and the device includes a signal receiving module and an on-off execution module, wherein:

[0169] A signal receiving module, used for receiving a first control signal sent by a first controller when all single-phase power converters are in a state of grid-connected power generation;

[0170] An on-off execution module is used to execute opening of the remaining switches based on a first control signal, so that the first controller sends a first state query request to each single-phase power converter when the target switch is closed and the remaining switches are opened, and determines the single-phase power converter whose grid phase sequence is the target phase circuit according to the first feedback information corresponding to the received first state query request; wherein the target switch is used to control the on-off of the single-phase power converter and the target phase circuit corresponding to the target phase circuit in the multi-phase power grid system, and the remaining switches are used to control the on-off of the single-phase power converter and the remaining phase circuits corresponding to the remaining phase circuits in the multi-phase power grid system, the target phase circuit corresponds to any one phase circuit in the multi-phase power grid system, and the remaining phase circuits correspond to phase circuits other than the target phase circuit in the multi-phase power grid system.

[0171] Each module in the above-mentioned power grid phase sequence determination device of the power converter can be implemented in whole or in part by software, hardware and a combination thereof. Each of the above-mentioned modules can be embedded in or independent of the processor in the network device in the form of hardware, or can be stored in the memory in the network device in the form of software, so that the processor can call and execute the operations corresponding to each of the above modules.

[0172] In an exemplary embodiment, a first controller is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the steps in the above-mentioned embodiments of the method for determining the phase sequence of the power grid in the first controller are implemented.

[0173] In an exemplary embodiment, a first controller is provided that includes a switch module, wherein the processor is configured to control the remaining phase circuits to be disconnected from the corresponding single-phase power converter through the switch module.

[0174] In an exemplary embodiment, a first controller is provided and connected to a second controller, and the process in which the processor controls the remaining phase circuits in a multi-phase power grid system to disconnect from the corresponding single-phase power converters includes: the processor is used to send a first control signal to the second controller, and the first control signal is used for the second controller to execute opening of the remaining switches.

[0175] In an exemplary embodiment, a second controller is provided, which includes a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps in the above-mentioned embodiments of the method for determining the phase sequence of a power grid in the second controller when executing the computer program.

[0176] In an exemplary embodiment, a relay is provided. The relay includes the second controller and switches provided in the above embodiment.

[0177] In an exemplary embodiment, a power system is provided, please refer to Figure 2 , the power system includes: a plurality of single-phase power converters, a relay and a first controller; wherein the first end of the first switch in the relay is connected to the first controller and a target phase circuit for connecting to a multi-phase power grid system, the second end of the first switch is connected to a single-phase power converter corresponding to the target phase circuit, the first ends of the remaining switches of the relay are connected to the first controller and the remaining phase circuits for connecting to the multi-phase power grid system, the second end of the second switch is connected to a single-phase power converter corresponding to the remaining phase circuits, the first controller includes a memory and a processor, the memory stores a computer program, and the processor implements the steps in the above-mentioned embodiments of the method for determining the power grid phase sequence of the power converter in the first controller when executing the computer program.

[0178] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments are implemented.

[0179] In one embodiment, a computer program product is provided, including a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0180] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0181] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0182] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0183] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for determining a power grid phase sequence of a power converter, characterized in that: The method is used for a first controller, and the method is used to determine the grid phase sequence corresponding to each single-phase power converter connected to a multi-phase grid system; the method comprises: When all the single-phase power converters are in a state of grid-connected power generation, controlling the remaining phase circuits in the multi-phase power grid system to be disconnected from the corresponding single-phase power converters; Sending a first status query request to each of the single-phase power converters; Determine, according to the received first feedback information corresponding to the first status query request, a single-phase power converter whose grid phase sequence is a target phase circuit; The target phase circuit corresponds to any one phase circuit in the multi-phase power grid system, and the remaining phase circuits correspond to phase circuits in the multi-phase power grid system except the target phase circuit.

2. The method according to claim 1, characterized in that: The communication method between the first controller and each of the single-phase power converters includes a wireless communication method or a power carrier communication method; The method of determining the grid phase sequence as a single-phase power converter of a target circuit according to the received first feedback information corresponding to the first status query request includes: Determine the grid phase sequence of the single-phase power converter whose first feedback information includes first state information as the target phase circuit, wherein the first state information is used to indicate that the corresponding single-phase power converter is in a working state; The grid phase sequence of the single-phase power converter whose first feedback information includes second state information is determined to be not the target phase circuit, and the second state information is used to indicate that the corresponding single-phase power converter is not in a working state.

3. The method according to claim 1, characterized in that The communication method between the first controller and each of the single-phase power converters includes a one-to-one wired communication method; The method of determining, according to the received first feedback information corresponding to the first status query request, a single-phase power converter whose grid phase sequence is a target phase circuit comprises: The grid phase sequence of the single-phase power converter that feeds back the first feedback information is determined as the target phase circuit.

4. The method according to claim 1, characterized in that The multi-phase power grid system is a three-phase power grid system, the target phase circuit includes a first phase circuit, and the remaining phase circuits include a second phase circuit and a third phase circuit; The controlling the remaining phase circuits in the multi-phase power grid system to be disconnected from the corresponding single-phase power converters includes: controlling the second phase circuit and the third phase circuit to be disconnected from the corresponding single-phase power converters; The method of determining, according to the received first feedback information corresponding to the first status query request, a single-phase power converter whose grid phase sequence is a target phase circuit comprises: According to the first feedback information, it is determined that the phase sequence of the power grid is a single-phase power converter of the first phase circuit.

5. The method according to claim 4, characterized in that After the step of determining, according to the received first feedback information corresponding to the first status query request, that the grid phase sequence is a single-phase power converter of a target phase circuit, the method further includes: Controlling the second phase circuit and the third phase circuit to be connected to corresponding single-phase power converters; When all the single-phase power converters are in a state of grid-connected power generation, controlling the first phase circuit and the third phase circuit to be disconnected from the corresponding single-phase power converters; Sending a second state query request to each of the single-phase power converters whose grid phase sequence is not the first phase circuit; According to the received second feedback information corresponding to the second state query request, it is determined that the phase sequence of the power grid is a single-phase power converter of the second phase circuit.

6. The method according to claim 5, characterized in that After the step of determining, according to the received second feedback information corresponding to the second state query request, that the grid phase sequence is a single-phase power converter of the second phase circuit, the method further includes: Controlling the first phase circuit and the third phase circuit to be connected to corresponding single-phase power converters; When all the single-phase power converters are in a state of grid-connected power generation, controlling the first phase circuit and the second phase circuit to be disconnected from the corresponding single-phase power converters; Sending a third state query request to each of the single-phase power converters whose grid phase sequence is not the first phase circuit and the second phase circuit; According to the received third feedback information corresponding to the third state query request, it is determined that the grid phase sequence is a single-phase power converter of the third phase circuit.

7. The method according to claim 5, characterized in that After the step of determining, according to the received second feedback information corresponding to the second state query request, that the grid phase sequence is a single-phase power converter of the second phase circuit, the method further includes: The grid phase sequence of the single-phase power converter whose grid phase sequence is not the first phase circuit and the second phase circuit is determined as the third phase.

8. The method according to claim 1, characterized in that Determine whether all the single-phase power converters are in a grid-connected power generation state by following the steps below: Sending a fourth status query request to all the single-phase power converters; If the first number is equal to the second number, it is determined that all the single-phase power converters are in a state of grid-connected power generation; the first number is the number of fourth feedback information corresponding to the fourth state query request received within a preset time length, and the second number is the number of single-phase power converters connected to the multi-phase power grid system; If the first number is not equal to the second number, it is determined that not all of the single-phase power converters are in a state of grid-connected power generation.

9. A method for determining the phase sequence of a power grid of a power converter, characterized in that: The method is used in a first controller, the first controller is communicatively connected with a second controller, the second controller is used to control the on-off between each single-phase power converter and a corresponding phase circuit of a multi-phase power grid system, the method is used to determine the grid phase sequence corresponding to each single-phase power converter connected to the multi-phase power grid system, and the method includes: When all the single-phase power converters are in a state of grid-connected power generation, a first control signal is sent to the second controller, wherein the first control signal is used for the second controller to execute opening of the remaining switches; Sending a first status query request to each of the single-phase power converters; Determine, according to the received first feedback information corresponding to the first status query request, a single-phase power converter whose grid phase sequence is a target phase circuit; Among them, the remaining switches are used to control the on and off of the single-phase power converters and the remaining phase circuits corresponding to the remaining phase circuits in the multi-phase power grid system, the target phase circuit corresponds to any one phase circuit in the multi-phase power grid system, and the remaining phase circuits correspond to the phase circuits in the multi-phase power grid system except the target phase circuit.

10. A method for determining the phase sequence of a power grid of a power converter, characterized in that: The method is used in a second controller, the second controller is used to control the on-off between each single-phase power converter and the corresponding phase circuit of the multi-phase power grid system, the method is used to determine the grid phase sequence corresponding to each single-phase power converter connected to the multi-phase power grid system, and the method includes: When all the single-phase power converters are in a state of grid-connected power generation, receiving a first control signal sent by a first controller; Based on the first control signal, the remaining switches are opened, so that the first controller sends a first state query request to each of the single-phase power converters when the target switch is closed and the remaining switches are opened, and determines the single-phase power converter whose grid phase sequence is the target phase circuit according to the first feedback information corresponding to the received first state query request; Among them, the target switch is used to control the on-off of the single-phase power converter and the target phase circuit corresponding to the target phase circuit in the multi-phase power grid system, and the remaining switches are used to control the on-off of the single-phase power converter and the remaining phase circuits corresponding to the remaining phase circuits in the multi-phase power grid system. The target phase circuit corresponds to any one phase circuit in the multi-phase power grid system, and the remaining phase circuits correspond to the phase circuits in the multi-phase power grid system except the target phase circuit.

11. A controller, comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 9 are implemented.

12. The controller according to claim 11, characterized in that: The first controller includes a switch module, and the process in which the processor controls the remaining phase circuits in the multi-phase power grid system to be disconnected from the corresponding single-phase power converter includes: the processor is used to control the remaining phase circuits to be disconnected from the corresponding single-phase power converter through the switch module.

13. A second controller, characterized in that: The second controller includes a memory and a processor, the memory stores a computer program, and is characterized in that the processor implements the steps of the method according to claim 10 when executing the computer program.

14. A power system, characterized in that: The power system comprises: a plurality of single-phase power converters, a relay and a first controller; wherein, A first end of the target switch in the relay is connected to the controller and a target phase circuit for connecting to a multi-phase power grid system, a second end of the target switch is connected to a single-phase power converter corresponding to the target phase circuit, a first end of the remaining switches of the relay is connected to the first controller and the remaining phase circuits for connecting to the multi-phase power grid system, and a second end of the remaining switches is connected to the single-phase power converter corresponding to the remaining phase circuits, wherein the target phase circuit corresponds to any one phase circuit in the multi-phase power grid system, and the remaining phase circuits correspond to phase circuits in the multi-phase power grid system except the target phase circuit; The first control comprises a memory and a processor, the memory stores a computer program, and the processor implements the steps of the method according to any one of claims 1 to 9 when executing the computer program.

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