Wiring detection circuit and wiring detection method

Abstract

The invention provides a wiring detection circuit and a wiring detection method, and belongs to the technical field of energy storage inverters. The circuit comprises a switch unit, a voltage sampling unit, a control processing unit and a first controllable switch, the first end of the switch unit is used for connecting a network side zero line, the second end of the switch unit is respectively connected with a load side zero line, the first end of the voltage sampling unit and the first sampling end of the control processing unit, and the third end of the switch unit is connected with the first control end of the control processing unit; the second end of the voltage sampling unit is connected with the first end of the first controllable switch; the second end of the first controllable switch is respectively connected with the second sampling end of the control processing unit, the ground wire and the shell of the energy storage inverter, and the third end of the first controllable switch is connected with the second control end of the control processing unit; and the control processing unit determines the wiring state of the grid-side zero line, the load-side zero line and / or the ground line based on the initial voltage and the comparison voltage. The applicability and the accuracy of the wiring detection circuit can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of energy storage inverters, and in particular to a wiring detection circuit and a wiring detection method. Background Art

[0002] As power technology matures, more and more power systems have introduced energy storage devices to store the power output of photovoltaic, wind power and other new energy generators, and use energy storage inverters to perform peak-shaving and valley-filling dynamic power compensation. In some power systems, the energy storage inverter needs to be connected to the ground wire (PE) separately, and the energy storage inverter also needs to be connected to the neutral wire (N wire) of the grid and the N wire of the load.

[0003] In the related art, in order to avoid safety problems caused by abnormal wiring of the energy storage inverter, related technicians often set up some detection circuits in the energy storage inverter to perform wiring detection. For example, the grounding condition of the casing can be judged by detecting the voltage sampling of the busbar (BUS)-to the casing. Since the AC component will be introduced when the N line and the PE line are short-circuited, it can be judged whether the current energy storage inverter has a poor grounding problem based on the AC component in the sampled DC voltage.

[0004] However, this solution can only detect whether there is a fault in the grounding wire, but cannot detect the neutral wire or zero wire. Moreover, in the three-phase line, TT system, and TN system power system, there may be a possibility that the AC component cannot be introduced or the AC component is weak, which may lead to misjudgment. Therefore, how to provide a grounding detection solution with strong applicability and high accuracy is a technical problem that needs to be solved urgently. Summary of the invention

[0005] The purpose of the present application is to provide a wiring detection circuit and a wiring detection method, which can improve the applicability and accuracy of the wiring detection circuit.

[0006] The embodiment of the present application is implemented as follows:

[0007] In a first aspect of an embodiment of the present application, there is provided a wiring detection circuit, the circuit comprising: a switch unit, a voltage sampling unit, a control processing unit and a first controllable switch;

[0008] The first end of the switch unit is used to connect the grid-side neutral line, the second end of the switch unit is respectively connected to the load-side neutral line, the first end of the voltage sampling unit and the first sampling end of the control processing unit, and the third end of the switch unit is connected to the first control end of the control processing unit; the switch unit is used to be turned on or off under the control of the control processing unit to control the grid-side neutral line to be connected to the circuit;

[0009] The second end of the voltage sampling unit is connected to the first end of the first controllable switch; the voltage sampling unit is used to sample the voltage difference between the ground line of the energy storage inverter and the grid-side neutral line and / or the load-side neutral line;

[0010] The second end of the first controllable switch is respectively connected to the second sampling end of the control processing unit, the ground wire and the housing of the energy storage inverter, and the third end of the first controllable switch is connected to the second control end of the control processing unit; the first controllable switch is used to be turned on under the control of the control processing unit to enable the voltage sampling unit to be powered on and work;

[0011] The control processing unit is used to sample the initial voltage of the voltage sampling unit when the switch unit is turned off, sample the comparison voltage of the voltage sampling unit when the switch unit is turned on, and determine the connection status of the grid-side neutral line, the load-side neutral line and / or the ground line based on the initial voltage and the comparison voltage.

[0012] Optionally, the voltage sampling unit includes at least one acquisition branch;

[0013] The first end of each of the acquisition branches is respectively connected to the second end of the switch unit, the load side neutral line and the first sampling end of the control processing unit, and the second end of each of the acquisition branches is respectively connected to the first end of the first controllable switch;

[0014] Wherein, at the same time, only one of the acquisition branches is connected to the first end of the first controllable switch;

[0015] Optionally, the voltage sampling unit comprises at least: a first resistor and a second resistor;

[0016] The first end of the first resistor is respectively connected to the second end of the switch unit, the load side neutral line and the first sampling end of the control processing unit, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is connected to the first end of the first controllable switch.

[0017] Optionally, the voltage sampling unit further includes: a third resistor and a fourth resistor;

[0018] The first end of the third resistor is connected to the first end of the first resistor, the second end of the third resistor is connected to the first end of the fourth resistor, and the second end of the fourth resistor is used to connect to the first end of the first controllable switch;

[0019] Wherein, at the same time, only one of the fourth resistor and the second resistor is connected to the first controllable switch.

[0020] Optionally, the voltage sampling unit further includes a second controllable switch;

[0021] The first end of the second controllable switch is used to connect the second end of the second resistor or the second end of the fourth resistor, the second end of the second controllable switch is connected to the first end of the first controllable switch, and the third end of the second controllable switch is connected to the third control end of the control processing unit;

[0022] The second controllable switch is used to connect to the second resistor or the fourth resistor under the control of the control processing unit.

[0023] Optionally, the switch unit further includes at least one third controllable switch;

[0024] Each of the third controllable switches is sequentially connected in series between the grid-side neutral line and the first end of the voltage sampling unit, and the control end of each of the third controllable switches is respectively connected to the fourth control end of the control processing unit;

[0025] The third controllable switch is used to be turned on or off under the control of the control processing unit to control the grid-side neutral line to be connected to the circuit.

[0026] Optionally, the control processing unit includes: an acquisition unit and a microcontroller unit (Microcontroller Unit, MCU for short);

[0027] The first input end of the acquisition unit is connected to the first end of the voltage sampling unit, the second input end of the acquisition unit is connected to the second end of the first controllable switch, and the output end of the acquisition unit is connected to the input end of the MCU; the acquisition unit is used to sample the initial voltage of the voltage sampling unit when the switch unit is turned off, sample the comparison voltage of the voltage sampling unit when the switch unit is turned on, and output the initial voltage and the comparison voltage to the MCU;

[0028] The first control terminal of the MCU is connected to the third terminal of the switch unit, and the second control terminal of the MCU is connected to the third terminal of the first controllable switch;

[0029] The MCU is used to determine the connection status of the grid-side neutral line, the load-side neutral line and / or the ground line based on the initial voltage and the comparison voltage.

[0030] A second aspect of an embodiment of the present application provides a wiring detection method, which is applied to any wiring detection circuit provided in the first aspect above, wherein the circuit includes: a switch unit, a voltage sampling unit, a control processing unit, and a first controllable switch; the method includes:

[0031] The control processing unit controls the switch unit to turn off, and controls the first controllable switch to turn on;

[0032] The control processing unit samples the voltage sampling unit in a preset manner to obtain an initial voltage;

[0033] The control processing unit controls the first controllable unit to be turned off, and controls the switch unit to be turned on;

[0034] The control processing unit controls the first controllable unit to be turned on, and resamples the voltage sampling unit in a preset manner to obtain a comparison voltage;

[0035] The control processing unit determines the connection status of the grid-side neutral line, the load-side neutral line and / or the ground line based on the initial voltage and the comparison voltage.

[0036] Optionally, when the voltage sampling unit includes at least two acquisition branches and a second controllable switch, the control processing unit samples the voltage sampling unit in a preset manner to obtain an initial voltage, including:

[0037] Sampling and recording the first voltage value of the voltage sampling unit once at a preset time interval until the sampling number reaches a preset threshold and stops sampling;

[0038] Controlling the second controllable switch to act, and re-sampling and recording the second voltage value of the voltage sampling unit once every preset time interval, until the sampling number reaches a preset threshold and stops sampling;

[0039] When it is determined that voltage sampling is performed on each of the at least two acquisition branches, the sampling is stopped, and the voltage value corresponding to each of the acquisition branches is used as the initial voltage respectively;

[0040] The second controllable switch is connected to one of the at least two collecting branches by default.

[0041] Optionally, the control processing unit determines the connection status of the grid-side neutral line, the load-side neutral line and / or the ground line based on the initial voltage and the comparison voltage, including:

[0042] calculating a voltage difference between the initial voltage and the comparison voltage;

[0043] When the voltage difference is greater than or equal to a preset voltage threshold, determining that the connection of the grid-side neutral line, the load-side neutral line and / or the ground line is normal;

[0044] When the voltage difference is less than a preset voltage threshold, it is determined that the connection of the grid-side neutral line, the load-side neutral line and / or the ground line is abnormal.

[0045] The beneficial effects of the embodiments of the present application include:

[0046] A wiring detection circuit provided in an embodiment of the present application is provided by setting a switch unit, a voltage sampling unit, a control processing unit and a first controllable switch in the wiring detection circuit. The first end of the switch unit is used to connect the grid-side neutral line, the second end of the switch unit is respectively connected to the load-side neutral line, the first end of the voltage sampling unit and the first sampling end of the control processing unit, and the third end of the switch unit is connected to the first control end of the control processing unit. The second end of the voltage sampling unit is connected to the first end of the first controllable switch. The second end of the first controllable switch is respectively connected to the second sampling end of the control processing unit, the ground line and the housing of the energy storage inverter, and the third end of the first controllable switch is connected to the second control end of the control processing unit.

[0047] Among them, since the energy storage inverter itself has a certain impedance, therefore, when the switch unit is turned off and the energy storage inverter is off-grid, there is also a voltage between the load neutral line and the ground line that can reflect the impedance of the energy storage inverter itself, that is, the initial voltage detected by the control processing unit through the voltage sampling unit. When the switch unit is turned on and the energy storage inverter is on the grid, the grid-side neutral line can be connected to the circuit, and then the grid-side neutral line can be connected in parallel to the load-side neutral line. In this way, the grid-side impedance can be introduced into the circuit, which will cause the voltage difference between the load-side neutral line and the ground line to change. However, if the ground line or the grid-side neutral line or the load-side neutral line is in poor contact or not connected correctly, the voltage difference between the load-side neutral line and the ground line will not change. Therefore, the connection state can be accurately determined by comparing the comparison voltage after the grid-side neutral line is connected to the circuit and the initial voltage when the grid-side neutral line is not connected to the circuit.

[0048] In addition, the circuit provided in this embodiment can not only detect the grid-side neutral line, the load-side neutral line and the ground line, but also the circuit can be applied to any other power grid except the IT standard without PE line, such as the TT standard, the TN standard, etc. Moreover, the circuit structure and control logic of the circuit are simple, and there is no need to introduce an additional AC component. Instead, the wiring state can be intuitively detected by detecting the voltage, and the operation of the entire energy storage inverter will not be affected after the wiring detection is completed.

[0049] In this way, the effect of improving the applicability and accuracy of the wiring detection circuit can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0051] Figure 1 A schematic diagram of the structure of a first wiring detection circuit provided in an embodiment of the present application;

[0052] Figure 2 A schematic diagram of the structure of a second wiring detection circuit provided in an embodiment of the present application;

[0053] Figure 3 A schematic diagram of the structure of a third wiring detection circuit provided in an embodiment of the present application;

[0054] Figure 4 A schematic diagram of the structure of a fourth wiring detection circuit provided in an embodiment of the present application;

[0055] Figure 5 A schematic diagram of the structure of a fifth wiring detection circuit provided in an embodiment of the present application;

[0056] Figure 6 A flowchart illustrating the structure of a wiring detection method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0058] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0059] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0060] In the description of the present application, it should be noted that the terms "first", "second", "third", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0061] In the description of this application, it should also be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0062] In the related art, in order to avoid safety problems caused by abnormal wiring of energy storage inverters, related technicians often set up some detection circuits in energy storage inverters to perform wiring detection. For example, the grounding condition of the casing can be judged by detecting the voltage sampling of the casing by BUS-. Since the AC component will be introduced when the N line and the PE line are short-circuited, it can be judged whether the current energy storage inverter has a poor grounding problem based on the AC component in the sampled DC voltage.

[0063] However, this solution can only detect whether there is a fault in the grounding wire, but cannot detect the neutral wire or zero wire. Moreover, in the three-phase line, TT system, and TN system power system, there may be a possibility that the AC component cannot be introduced or the AC component is weak, which may lead to misjudgment. Therefore, how to provide a grounding detection solution with strong applicability and high accuracy is a technical problem that needs to be solved urgently.

[0064] To this end, the embodiment of the present application provides a wiring detection circuit, by setting a switch unit, a voltage sampling unit, a control processing unit and a first controllable switch in the circuit; the first end of the switch unit is used to connect the grid-side neutral line, the second end of the switch unit is respectively connected to the load-side neutral line, the first end of the voltage sampling unit and the first sampling end of the control processing unit, and the third end of the switch unit is connected to the first control end of the control processing unit; the second end of the voltage sampling unit is connected to the first end of the first controllable switch; the second end of the first controllable switch is respectively connected to the second sampling end of the control processing unit, the ground wire and the housing of the energy storage inverter, and the third end of the first controllable switch is connected to the second control end of the control processing unit. In this way, the applicability and accuracy of the wiring detection circuit can be improved.

[0065] The embodiment of the present application is described by taking the wiring detection circuit used in the energy storage inverter as an example, but it does not mean that the embodiment of the present application can only be used for wiring detection in the energy storage inverter.

[0066] The wiring detection circuit provided in the embodiment of the present application is explained in detail below.

[0067] Figure 1 This is a schematic diagram of the structure of a wiring detection circuit provided by this application. Figure 1 The embodiment of the present application provides a wiring detection circuit 100, and the circuit 100 includes: a switch unit 101, a voltage sampling unit 102, a control processing unit 103 and a first controllable switch K1.

[0068] The first end of the switch unit 101 is used to connect the grid-side neutral line, the second end of the switch unit 101 is respectively connected to the load-side neutral line, the first end of the voltage sampling unit 102 and the first sampling end of the control processing unit 103, and the third end of the switch unit 101 is connected to the first control end of the control processing unit 103.

[0069] The second end of the voltage sampling unit 102 is connected to the first end of the first controllable switch K1 .

[0070] The second end of the first controllable switch K1 is respectively connected to the second sampling end of the control processing unit 103 , the ground wire and the housing of the energy storage inverter, and the third end of the first controllable switch K1 is connected to the second control end of the control processing unit 103 .

[0071] The switch unit 101 is used to be turned on or off under the control of the control processing unit 103 to control the grid-side neutral line access circuit 100 .

[0072] Optionally, in general, the switch unit 101 may be a switch device in the energy storage inverter for switching the energy storage inverter off-grid and on-grid. The switch unit 101 may include any device that can realize a switching function, such as the switch unit 101 may include at least one relay, or at least one contactor, or any other possible switch device, which is not limited in the embodiment of the present application.

[0073] Specifically, in the default state, the switch unit 101 may be turned off. At this time, the energy storage inverter is in an off-grid state, and the grid-side neutral line (such as Figure 1 Grid N in the circuit 100 is not connected. Under the control of the control processing unit 103, the switch unit 101 can be switched to the on state, at which time the energy storage inverter is in the grid-connected state, and the grid-side neutral line is connected to the circuit 100.

[0074] In this embodiment, the voltage sampling unit 102 may be any module capable of voltage division. For example, the voltage sampling unit 102 may include any possible components such as a voltage dividing resistor and a voltage dividing diode, which is not limited in this embodiment of the present application.

[0075] Optionally, the voltage sampling unit 102 is used to sample the voltage difference between the ground line of the energy storage inverter and the grid-side neutral line and / or the load-side neutral line.

[0076] It can be understood that when the switch unit 101 is turned off and the grid-side neutral line is not connected to the circuit 100, the voltage across the voltage sampling unit 102 is the load-side neutral line (eg Figure 1 Load N) and ground (such as Figure 1 At this time, the voltage sampled by the voltage sampling unit 102 can be used to reflect the physical parameters matched by the impedance of the energy storage inverter itself.

[0077] When the switch unit 101 is turned on and the grid-side neutral line is connected to the circuit 100, the voltage across the voltage sampling unit 102 is the voltage difference between the load-side neutral line and the grid-side neutral line and the ground line after the neutral line is connected in parallel. At this time, the voltage sampled by the voltage sampling unit 102 can reflect the connection status of the load-side neutral line, the grid-side neutral line and / or the ground line.

[0078] Optionally, the grid-side neutral line refers to the neutral line in the commercial power network, and the load-side neutral line is the neutral line of any electrical equipment connected to the energy storage inverter.

[0079] In this embodiment, the first controllable switch K1 may be any possible switch device. For example, the first controllable switch K1 may be a relay or any possible element such as a contactor, which is not limited in this embodiment of the present application.

[0080] Optionally, the first controllable switch K1 may be turned off in a default state, for example, the first controllable switch K1 may be a normally open contact of a relay. The first controllable switch K1 is used to be turned on under the control of the control processing unit 103 to power on the voltage sampling unit 102 to operate.

[0081] In this embodiment, the control processing unit 103 may be any device that may have the functions of processing, computing, sampling, identifying, controlling, etc. Moreover, the control processing unit 103 may be a unit composed of one device, or a unit composed of multiple devices. This embodiment of the application does not limit this.

[0082] Optionally, the control processing unit 103 is used to sample the initial voltage of the voltage sampling unit 102 when the switch unit 101 is turned off, sample the comparison voltage of the voltage sampling unit 102 when the switch unit 101 is turned on, and determine the connection status of the grid-side neutral line, the load-side neutral line and / or the ground line based on the initial voltage and the comparison voltage.

[0083] In this embodiment, the control processing unit 103 can sample the voltage of the voltage sampling unit 102 in any possible way. For example, the control processing unit 103 can sample the voltage sampling unit 102 once at a specific moment, and use the voltage collected this time as the initial voltage or the comparison voltage. It is also possible to sample the voltage sampling unit 102 multiple times based on a preset interval time within a certain period of time, and use the voltage collected multiple times as the initial voltage or the comparison voltage, or use the average value of the voltage collected multiple times as the initial voltage or the comparison voltage. The embodiment of the present application does not limit this.

[0084] Optionally, the initial voltage refers to the voltage across the voltage sampling unit 102 when the switch unit 101 is turned off and the grid-side neutral line is not connected to the circuit 100. The initial voltage can be used to reflect the physical parameters corresponding to the impedance of the energy storage inverter itself.

[0085] Optionally, the comparison voltage refers to the voltage across the voltage sampling unit 102 when the switch unit 101 is turned on and the grid-side neutral line is connected to the circuit 100. The comparison voltage can be used to reflect the connection status of the load-side neutral line, the grid-side neutral line and / or the ground line.

[0086] In this embodiment, the connection status can be used to indicate whether the grid-side neutral line, the load-side neutral line and / or the ground line have problems such as poor contact, disconnection, etc.

[0087] Exemplarily, the control processing unit 103 can determine the wiring status in the following manner: the control processing unit 103 subtracts the initial voltage from the comparison voltage to determine the voltage difference between the initial voltage and the comparison voltage; compares the voltage difference with a preset voltage threshold; when it is determined that the voltage difference is greater than or equal to the preset voltage threshold, determines that the wiring status of the grid-side neutral line, the load-side neutral line and / or the ground line is a normal state; when it is determined that the voltage difference is less than the preset voltage threshold, determines that the wiring status of the grid-side neutral line, the load-side neutral line and / or the ground line is an abnormal state such as not being connected or having poor contact.

[0088] It is worth noting that in order to better introduce the circuit 100 provided in the embodiment of the present application, the working principle of the circuit 100 is briefly explained below:

[0089] In the default state or the sleep state, the switch unit 101 is turned off and the first controllable switch K1 is disconnected. At this time, the voltage sampling unit 102 does not work, and the control processing unit 103 does not collect the initial voltage or the comparison voltage. At the same time, the control processing unit 103 does not control the switch unit 101 and / or the first controllable switch K1.

[0090] When wiring detection is required, the control processing unit 103 controls the switch unit 101 to remain in the off state and controls the first controllable switch K1 to be turned on. At this time, a path is formed between the load side neutral line (Load N), the voltage sampling unit 102, and the ground line (PE) through the first controllable switch K1. At this time, the voltage sampling unit 102 can sample the voltage difference between the load side neutral line and the ground line, that is, the initial voltage.

[0091] After collecting the initial voltage, the control processing unit 103 controls the first controllable switch K1 to turn off, and then controls the switch unit 101 to turn on, so that the grid-side neutral line (Grid N) is connected in parallel with the load-side neutral line, and then controls the first controllable switch K1 to turn on, so that the grid-side neutral line, the load-side neutral line (Load N), the voltage sampling unit 102, and the ground line (PE) form a path. At this time, the voltage sampling unit 102 can sample the voltage difference between the load-side neutral line and the ground line, that is, the comparison voltage.

[0092] Then, the control processing unit 103 may determine the connection state based on the comparison voltage and the initial voltage in the above manner.

[0093] In addition, when the control processing unit 103 determines that the connection status is an abnormal state or a fault state, it can also output corresponding prompt information (such as sound signals, text signals, light signals, and any other possible information) to prompt the user or relevant technical personnel to handle it.

[0094] It is worth noting that in this embodiment, since the energy storage inverter itself has a certain impedance, when the switch unit 101 is turned off and the energy storage inverter is off-grid, there is also a voltage between the load neutral line and the ground line that can reflect the impedance of the energy storage inverter itself, that is, the initial voltage detected by the control processing unit 103 through the voltage sampling unit 102. When the switch unit 101 is turned on and the energy storage inverter is on the grid, the grid-side neutral line can be connected to the circuit 100, and then the grid-side neutral line can be connected in parallel to the load-side neutral line. In this way, the grid-side impedance can be introduced into the circuit 100, which will cause the voltage difference between the load-side neutral line and the ground line to change. However, if the ground line or the grid-side neutral line or the load-side neutral line is in poor contact or is not properly connected, the voltage difference between the load-side neutral line and the ground line will not change. Therefore, the connection state can be accurately determined by comparing the comparison voltage after the grid-side neutral line is connected to the circuit 100 and the initial voltage when the grid-side neutral line is not connected to the circuit 100.

[0095] In the embodiment of the present application, a switch unit 101, a voltage sampling unit 102, a control processing unit 103 and a first controllable switch K1 are provided in the wiring detection circuit 100. The first end of the switch unit 101 is used to connect the grid-side neutral line, the second end of the switch unit 101 is respectively connected to the load-side neutral line, the first end of the voltage sampling unit 102 and the first sampling end of the control processing unit 103, and the third end of the switch unit 101 is connected to the first control end of the control processing unit 103. The second end of the voltage sampling unit 102 is connected to the first end of the first controllable switch K1. The second end of the first controllable switch K1 is respectively connected to the second sampling end of the control processing unit 103, the ground line and the housing of the energy storage inverter, and the third end of the first controllable switch K1 is connected to the second control end of the control processing unit 103.

[0096] Among them, since the energy storage inverter itself has a certain impedance, therefore, when the switch unit 101 is turned off and the energy storage inverter is off-grid, there is also a voltage between the load neutral line and the ground line that can reflect the impedance of the energy storage inverter itself, that is, the initial voltage detected by the control processing unit 103 through the voltage sampling unit 102. When the switch unit 101 is turned on and the energy storage inverter is on the grid, the grid-side neutral line can be connected to the circuit 100, and then the grid-side neutral line can be connected in parallel to the load-side neutral line. In this way, the grid-side impedance can be introduced into the circuit 100, which will cause the voltage difference between the load-side neutral line and the ground line to change. However, if the ground line or the grid-side neutral line or the load-side neutral line is in poor contact or not connected correctly, the voltage difference between the load-side neutral line and the ground line will not change. Therefore, the connection state can be accurately determined by comparing the comparison voltage after the grid-side neutral line is connected to the circuit 100 and the initial voltage when the grid-side neutral line is not connected to the circuit 100.

[0097] In addition, the circuit 100 provided in this embodiment can not only detect the grid-side neutral line, the load-side neutral line and the ground line, but also the circuit 100 can be applied to any other power grid except the IT standard without PE line, such as the TT standard, the TN standard, etc. Moreover, the circuit structure and control logic of the circuit 100 are simple, and there is no need to introduce an additional AC component. Instead, the wiring state can be intuitively detected by detecting the voltage, and the operation of the entire energy storage inverter will not be affected after the wiring detection is completed.

[0098] In this way, the applicability and accuracy of the wiring detection circuit 100 can be improved.

[0099] In a possible implementation, the voltage sampling unit 102 includes at least one sampling branch.

[0100] The first end of each acquisition branch is respectively connected to the second end of the switch unit 101, the load side neutral line and the first sampling end of the control processing unit 103, and the second end of each acquisition branch is respectively connected to the first end of the first controllable switch K1.

[0101] Among them, at the same time, only one of the acquisition branches is connected to the first end of the first controllable switch K1.

[0102] Optionally, each acquisition branch can be used to sample the voltage difference between the load side neutral line and the ground line. Each acquisition branch can include at least one element for voltage division, such as a voltage division resistor or a voltage division diode.

[0103] In this embodiment, different acquisition branches may have impedances of different magnitudes.

[0104] For example, if the voltage sampling unit 102 includes only one acquisition branch, the control processing unit 103 may directly perform acquisition on the acquisition branch in the manner described in the above embodiment to obtain a set of initial voltages and comparison voltages.

[0105] For another example, if the voltage sampling unit 102 includes two acquisition branches, the control processing unit 103 can respectively acquire data from each acquisition branch in the following manner to obtain multiple groups of initial voltages and comparison voltages:

[0106] Assume that in the default state, the first acquisition branch in the voltage sampling unit 102 is connected to the load side neutral line (LoadN) and the first controllable switch K1, and the control processing unit 103 controls the switch unit 101 to remain in the off state and controls the first controllable switch K1 to be turned on. At this time, the load side neutral line, the first acquisition branch in the voltage sampling unit 102, and the ground line (PE) form a path through the first controllable switch K1. At this time, the voltage sampling unit 102 can sample the voltage difference between the load side neutral line and the ground line to obtain a first group of initial voltages of the first acquisition branch.

[0107] Then, by any possible means, the first acquisition branch in the voltage sampling unit 102 is disconnected from the load side neutral line and the first controllable switch K1, and the second acquisition branch in the voltage sampling unit 102 is connected to the load side neutral line and the first controllable switch K1. At this time, the load side neutral line, the second acquisition branch in the voltage sampling unit 102, and the ground line (PE) can form a path through the first controllable switch K1. At this time, the voltage sampling unit 102 can sample the voltage difference between the load side neutral line and the ground line to obtain a second group of initial voltages of the second acquisition branch.

[0108] In this way, the initial voltages of the two acquisition branches can be obtained respectively.

[0109] Furthermore, after collecting the initial voltage of the first collection branch, the control processing unit 103 controls the first controllable switch K1 to turn off, and then controls the switch unit 101 to turn on, so that the grid-side neutral line (Grid N) is connected in parallel with the load-side neutral line, and then controls the first controllable switch K1 to turn on, so that the grid-side neutral line, the load-side neutral line (Load N), the first collection branch in the voltage sampling unit 102, and the ground line (PE) form a path. At this time, the voltage sampling unit 102 can sample the voltage difference between the load-side neutral line and the ground line to obtain the comparison voltage of the first collection branch.

[0110] Then, the control processing unit 103 controls the switch unit 101 to be turned off again and controls the first controllable switch K1 to be turned on. At this time, the load side neutral line (Load N), the first acquisition branch in the voltage sampling unit 102, and the ground line (PE) form a path through the first controllable switch K1. At this time, the voltage sampling unit 102 can sample the voltage difference between the load side neutral line and the ground line to obtain the comparison voltage of the first acquisition branch.

[0111] Furthermore, by any possible means, the first acquisition branch in the voltage sampling unit 102 is disconnected from the load side neutral line and the first controllable switch K1, and the second acquisition branch in the voltage sampling unit 102 is connected to the load side neutral line and the first controllable switch K1. At this time, the load side neutral line, the second acquisition branch in the voltage sampling unit 102, and the ground line (PE) can form a path through the first controllable switch K1. At this time, the voltage sampling unit 102 can sample the voltage difference between the load side neutral line and the ground line to obtain a second group of comparison voltages of the second acquisition branch.

[0112] In this way, the comparison voltages of the two acquisition branches can be obtained respectively.

[0113] It can be understood that if two groups of comparison voltages and two groups of initial voltages are collected respectively, the control processing unit 103 can compare the comparison voltages and the initial voltages respectively in the above manner to determine the wiring status.

[0114] Exemplarily, the initial voltage and comparison voltage corresponding to the first acquisition branch are recorded as initial voltage 1 and comparison voltage 1 respectively, and the initial voltage and comparison voltage corresponding to the second acquisition branch are recorded as initial voltage 2 and comparison voltage 2 respectively, and it is assumed that the above preset voltage threshold is 2V.

[0115] If the difference between the initial voltage 1 and the comparison voltage 1 is greater than or equal to 2V, and the difference between the initial voltage 2 and the comparison voltage 2 is also greater than or equal to 2V, then it can be determined that the grid-side neutral line, the load-side neutral line and the ground line are well connected, allowing grid connection and allowing the energy storage inverter to operate normally.

[0116] If the difference between the initial voltage 1 and the comparison voltage 1 is less than 2V, and / or the difference between the initial voltage 2 and the comparison voltage 2 is less than 2V, then it is determined that the grid-side neutral line, the load-side neutral line and / or the ground line have poor contact or are not connected.

[0117] It is worth noting that the comparison voltage and the initial voltage detected based on different acquisition branches can be used as different control groups to perform double verification to ensure the reliability of the wiring detection circuit 100.

[0118] In a possible implementation, when the voltage sampling unit 102 includes only one acquisition branch, see Figure 2 The voltage sampling unit 102 at least includes: a first resistor R1 and a second resistor R2.

[0119] The first end of the first resistor R1 is connected to the second end of the switch unit 101, the load side neutral line and the first sampling end of the control processing unit 103 respectively, the second end of the first resistor R1 is connected to the first end of the second resistor R2, and the second end of the second resistor R2 is connected to the first end of the first controllable switch K1.

[0120] Optionally, the first resistor R1 and the second resistor R2 may be resistors of any resistance value. Generally, a resistor of 100KΩ or more may be selected as the first resistor R1 and the second resistor R2. Moreover, the resistance values ​​of the first resistor R1 and the second resistor R2 may be the same or different. This embodiment of the application does not limit this.

[0121] It is worth noting that the first resistor R1 and the second resistor R2 are connected between the load-side neutral line and the first controllable switch K1, and the first controllable switch K1 is connected to the ground line. Therefore, when the first controllable switch K1 is turned on, the first resistor R1 and the second resistor R2 can accurately sample the voltage difference between the load-side neutral line and the first controllable switch K1 (that is, the initial voltage), and when the grid-side neutral line is connected in parallel with the load-side neutral line, the voltage difference between the load-side neutral line and the first controllable switch K1 (that is, the comparison voltage).

[0122] In a possible implementation, when the voltage sampling unit 102 includes two acquisition branches, Figure 2 On the basis of Figure 3 The voltage sampling unit 102 further includes: a third resistor R3 and a fourth resistor R4.

[0123] A first end of the third resistor R3 is connected to a first end of the first resistor R1 , a second end of the third resistor R3 is connected to a first end of the fourth resistor R4 , and a second end of the fourth resistor R4 is used to connect to a first end of the first controllable switch K1 .

[0124] At the same time, only one of the fourth resistor R4 and the second resistor R2 is connected to the first controllable switch K1.

[0125] Optionally, the third resistor R3 and the fourth resistor R4 may be resistors of any resistance value. Generally, a resistor of 100KΩ or more may be selected as the third resistor R3 and the fourth resistor R4. Moreover, the resistance values ​​of the third resistor R3 and the fourth resistor R4 may be the same or different. This embodiment of the application does not limit this.

[0126] In this embodiment, the total resistance after the third resistor R3 and the fourth resistor R4 are connected in series is generally different from the total resistance after the first resistor R1 and the second resistor R2 are connected in series. For example, the total resistance after the third resistor R3 and the fourth resistor R4 are connected in series can be 0.5 times, 2 times, or any other possible multiples of the total resistance after the first resistor R1 and the second resistor R2 are connected in series. This embodiment of the application is not limited to this.

[0127] It is worth noting that, in a special case, if the voltage of the energy storage inverter itself is equal to the voltage difference between the grid-side neutral line and the ground line, even if the neutral lines and the ground line are correctly connected, it may cause the voltage to remain unchanged when the grid-side neutral line is connected in parallel to the load-side neutral line.

[0128] Therefore, by setting two or more acquisition branches, two or more groups of initial voltages and comparison voltages are collected based on each acquisition branch for comparison, thus eliminating the problem of misdetection due to special circumstances. In this way, the practicality and reliability of the wiring detection circuit 100 can be improved.

[0129] In a possible implementation, see Figure 3 , the voltage sampling unit 102 also includes a second controllable switch K2.

[0130] The first end of the second controllable switch K2 is used to connect the second end of the second resistor R2 or the second end of the fourth resistor R4, the second end of the second controllable switch K2 is connected to the first end of the first controllable switch K1, and the third end of the second controllable switch K2 is connected to the third control end of the control processing unit 103.

[0131] The second controllable switch K2 is used to be connected to the second resistor R2 or the fourth resistor R4 under the control of the control processing unit 103 .

[0132] Optionally, the second controllable switch K2 may be any controllable switch device, for example, the second controllable switch K2 may be a relay, a contactor, or any other possible switch, which is not limited in the embodiment of the present application.

[0133] In this embodiment, the second controllable switch K2 can be connected to the second end of the second resistor R2 in a default state. After the control processing unit 103 controls, the second controllable switch K2 can be disconnected from the second resistor R2 and connected to the second end of the fourth resistor R4.

[0134] In this way, automatic switching can be achieved to perform voltage sampling on each sampling branch in the voltage sampling unit 102 respectively.

[0135] It should be noted that the embodiments of the present application are described by taking the voltage sampling unit 102 as including one acquisition branch and two acquisition branches respectively, but it does not mean that the wiring detection circuit 100 provided in the present application can only include one or two acquisition branches. In actual applications, three or more acquisition branches can be set according to actual needs for comparison, and the embodiments of the present application are not limited to this.

[0136] For a possible implementation, see Figure 4 , the switch unit 101 also includes at least one third controllable switch K3.

[0137] Each third controllable switch K3 is serially connected between the grid-side neutral line and the first end of the voltage sampling unit 102 , and a control end of each third controllable switch K3 is connected to a fourth control end of the control processing unit 103 .

[0138] The third controllable switch K3 is used to be turned on or off under the control of the control processing unit 103 to control the grid-side neutral line access circuit 100 .

[0139] In this embodiment, the third controllable switch K3 may be disconnected in the default state, and when the third controllable switch K3 is disconnected, the energy storage inverter is in an off-grid state, and at this time, the grid-side neutral line is not connected to the circuit 100. The third controllable switch K3 may be closed under the control of the control processing unit 103, and when the third controllable switch K3 is closed, the energy storage inverter is in a grid-connected state, and at this time, the grid-side neutral line is connected to the circuit 100.

[0140] It is worth noting that, see Figure 4 , Figure 4 The switch unit 101 in the circuit 100 shown in the figure includes two third controllable switches K3, so that the problem that the energy storage inverter cannot be disconnected from the grid due to a failure of one third controllable switch K3 can be prevented, and the safety of the energy storage inverter and the circuit 100 can be improved. For the specific connection relationship, see Figure 4, the embodiments of the present application will not be described in detail here.

[0141] For a possible implementation, see Figure 5 The control processing unit 103 includes: a collection unit 1031 and an MCU 1032 .

[0142] The first input terminal of the acquisition unit 1031 is connected to the first terminal of the voltage sampling unit 102, the second input terminal of the acquisition unit 1031 is connected to the second terminal of the first controllable switch K1, and the output terminal of the acquisition unit 1031 is connected to the input terminal of the MCU 1032. The first control terminal of the MCU 1032 is connected to the third terminal of the switch unit 101, and the second control terminal of the MCU 1032 is connected to the third terminal of the first controllable switch K1.

[0143] In this embodiment, the acquisition unit 1031 is used to sample the initial voltage of the voltage sampling unit 102 when the switch unit 101 is turned off, sample the comparison voltage of the voltage sampling unit 102 when the switch unit 101 is turned on, and output the initial voltage and the comparison voltage to the MCU1032.

[0144] Optionally, the acquisition unit 1031 may be any device capable of performing voltage detection, which is not limited in the embodiment of the present application.

[0145] Optionally, MCU1032 is used to determine the connection state of the grid-side neutral line, the load-side neutral line and / or the ground line based on the initial voltage and the comparison voltage. Specifically, it can be performed by any of the methods provided in the above embodiments, and the embodiments of the present application are not limited to this.

[0146] In addition, the third control terminal of the MCU1032 can also be connected to the third terminal of the second controllable switch K2, and the fourth control terminal of the MCU1032 can also be connected to the control terminals of each third controllable switch K3. Moreover, if there are multiple third controllable switches K3, then there can also be multiple fourth control terminals of the MCU1032 to achieve separate control of each third controllable switch K3, which is not limited in the embodiment of the present application.

[0147] In this way, the sampling unit 1031 can accurately sample the initial voltage and the comparison voltage, and then the MCU 1032 can determine whether the connection of the energy storage inverter is normal based on the initial voltage and the comparison voltage. In addition, the MCU 1032 can control each controllable switch to realize the automation of the connection detection circuit 100.

[0148] The following describes a wiring detection method for enabling the wiring detection circuit provided in the present application to achieve corresponding functions. The specific implementation process and technical effects are described above and will not be repeated below.

[0149] Figure 6 is a flow chart of a wiring detection method provided in an embodiment of the present application. The wiring detection method is applied to the wiring detection circuit 100 provided in any of the above embodiments, and can be specifically executed by the control processing unit 103 in the wiring detection circuit 100. Figure 6 , the method comprising:

[0150] Step 2001: The control processing unit controls the switch unit to turn off, and controls the first controllable switch to turn on.

[0151] Optionally, the control processing unit may be the above-mentioned control processing unit 103, the switch unit may be the above-mentioned switch unit 101, and the first controllable switch may be the above-mentioned first controllable switch K1.

[0152] It is worth noting that by controlling the switch unit to be turned off, the grid-side neutral line can be disconnected from the wiring detection circuit, making the energy storage inverter off-grid. In addition, by controlling the first controllable switch to be turned on, the voltage sampling unit in the wiring detection circuit 100 can be powered on and divided, which is convenient for collecting voltage.

[0153] Step 2002: The control processing unit samples the voltage sampling unit in a preset manner to obtain an initial voltage.

[0154] Optionally, the voltage sampling unit may be the voltage sampling unit 102 mentioned above.

[0155] Optionally, the preset method may be a sampling method set by relevant technical personnel according to actual needs. For example, the preset method may instruct the control processing unit to sample the voltage sampling unit a certain number of times at a certain interval. The embodiment of the present application does not limit this.

[0156] Step 2003: The control processing unit controls the first controllable unit to be turned off, and controls the switch unit to be turned on.

[0157] It should be noted that after collecting the initial voltage, controlling the first controllable unit to turn off can avoid the impact current that may occur during the process of controlling the switch unit to turn on, causing damage to the voltage sampling unit and / or the control processing unit. After controlling the switch unit to turn on, the grid-side neutral line can be connected to the wiring detection circuit, so that the energy storage inverter is in a grid-connected state, which is convenient for subsequent sampling and comparison of voltage.

[0158] Step 2004: the control processing unit controls the first controllable unit to be turned on, and resamples the voltage sampling unit in a preset manner to obtain a comparison voltage.

[0159] It is worth noting that by sampling in the same manner to obtain the comparison voltage, the problem of a difference between the comparison voltage and the initial voltage due to different sampling methods, which in turn affects the detection result, can be avoided.

[0160] Step 2005: The control processing unit determines the connection status of the grid-side neutral line, the load-side neutral line and / or the ground line based on the initial voltage and the comparison voltage.

[0161] Optionally, the control processing unit may determine the connection status by any of the methods in the above embodiments, which is not limited in the embodiments of the present application.

[0162] In a possible implementation, when the voltage sampling unit includes at least two acquisition branches and the second controllable switch, two acquisition branches are specifically taken as an example in the embodiment of the present application. The control processing unit samples the voltage sampling unit in a preset manner to obtain an initial voltage, including:

[0163] Step 2006: sampling and recording the first voltage value of the voltage sampling unit once at a preset time interval, and stopping sampling when the sampling number reaches a preset threshold.

[0164] Optionally, the preset duration and the preset threshold can be set by relevant technical personnel according to actual needs. Generally, the preset duration can be 20ms and the preset threshold can be 50 times, which is not limited in the embodiment of the present application.

[0165] Optionally, the first voltage value may refer to a voltage obtained by the control processing unit sampling a first acquisition branch in the voltage sampling unit.

[0166] Optionally, after stopping sampling, the first voltage values ​​obtained by sampling can be used as the initial voltage corresponding to the first acquisition branch, or the average value of the first voltage values ​​obtained by sampling can be used as the initial voltage corresponding to the first acquisition branch. This embodiment of the present application does not limit this.

[0167] Step 2007: Control the second controllable switch to act, and re-sample and record the second voltage value of the voltage sampling unit once every preset time interval, until the sampling number reaches a preset threshold and stops sampling.

[0168] The second controllable switch is connected to one of the at least two collecting branches by default.

[0169] Optionally, after controlling the second controllable switch to act, a collection branch in the voltage sampling unit connected to the control processing unit may be switched.

[0170] Optionally, the second voltage value may refer to a voltage obtained by the control processing unit sampling any acquisition branch in the voltage sampling unit except the first acquisition branch.

[0171] Optionally, after stopping sampling, the second voltage values ​​sampled for any acquisition branch can be used as the initial voltage corresponding to any acquisition branch, or the average value of the second voltage values ​​sampled can be used as the initial voltage corresponding to any acquisition branch. This embodiment of the present application does not limit this.

[0172] Step 2008: When it is determined that the voltage of each of the at least two acquisition branches is sampled, the sampling is stopped, and the voltage value corresponding to each acquisition branch is used as the initial voltage.

[0173] It should be noted that when the voltage sampling unit includes more than two acquisition branches, step 2007 can be repeatedly executed so that the control processing unit can collect the initial voltage corresponding to each acquisition branch until each acquisition branch in the voltage sampling unit completes the initial voltage, and then step 2008 is executed.

[0174] It is understandable that the control processing unit samples the comparison voltage in a similar manner to the initial voltage, and specific steps may be referred to steps 2006 to 2008, which will not be elaborated in the present embodiment of the application.

[0175] In a possible implementation, the control processing unit determines the connection state of the grid-side neutral line, the load-side neutral line and / or the ground line based on the initial voltage and the comparison voltage, including:

[0176] Step 2009: Calculate the voltage difference between the initial voltage and the comparison voltage.

[0177] Exemplarily, if the voltage sampling unit includes only one acquisition branch, the difference between the initial voltage and the comparison voltage can be directly calculated, and the absolute value of the difference is used as the voltage difference.

[0178] For another example, if the voltage sampling unit includes only two or more acquisition branches, then it is necessary to make a difference between the initial voltage and the comparison voltage corresponding to the same acquisition branch to obtain the difference corresponding to each acquisition branch, and use the absolute value of each difference as the voltage difference corresponding to each acquisition branch.

[0179] Step 2010: When the voltage difference is greater than or equal to a preset voltage threshold, determine that the connection of the grid-side neutral line, the load-side neutral line and / or the ground line is normal.

[0180] Optionally, the preset voltage threshold may be set by relevant technical personnel according to actual needs. For example, the preset voltage threshold may be 2V or any other possible value, which is not limited in the embodiments of the present application.

[0181] It can be understood that by setting the preset voltage threshold, it is possible to avoid the wiring detection circuit from making misjudgments due to voltage fluctuations caused by operating conditions or performance changes of the energy storage inverter during normal operation, thereby improving the reliability of the wiring detection method.

[0182] Step 2011: when the voltage difference is less than a preset voltage threshold, determining that the grid-side neutral line, the load-side neutral line and / or the ground line are abnormally connected.

[0183] Exemplarily, assuming that the voltage sampling unit includes two acquisition branches, the initial voltage and comparison voltage corresponding to the first acquisition branch are recorded as initial voltage 1 and comparison voltage 1, respectively, and the initial voltage and comparison voltage corresponding to the second acquisition branch are recorded as initial voltage 2 and comparison voltage 2, respectively, and it is assumed that the above-mentioned preset voltage threshold is 3V.

[0184] If the difference between the initial voltage 1 and the comparison voltage 1 is greater than or equal to 3V, and the difference between the initial voltage 2 and the comparison voltage 2 is also greater than or equal to 3V, then it can be determined that the grid-side neutral line, the load-side neutral line and the ground line are well connected, allowing grid connection and allowing the energy storage inverter to operate normally.

[0185] If the difference between the initial voltage 1 and the comparison voltage 1 is less than 3V, and / or the difference between the initial voltage 2 and the comparison voltage 2 is less than 3V, then it is determined that the grid-side neutral line, the load-side neutral line and / or the ground line have poor contact or are not connected.

[0186] It is worth noting that the voltage difference between the initial voltage and the comparison voltage can reflect whether the grid-side impedance is introduced into the circuit 100 when the grid-side neutral line is connected to the circuit through the switch unit. If the voltage difference between the load-side neutral line and the ground line (that is, the initial voltage and the comparison voltage) changes before and after the grid-side neutral line is connected, it can be determined that the wiring of each line is normal; if the voltage difference between the load-side neutral line and the ground line (that is, the initial voltage and the comparison voltage) does not change significantly before and after the grid-side neutral line is connected, it can be determined that at least one of the lines is abnormally wired.

[0187] The above method is used to control the wiring detection circuit provided in the above embodiment to work so that the wiring detection circuit can achieve the corresponding function. The implementation principle and technical effect are similar and will not be repeated here.

[0188] It is understandable that, since the wiring detection circuit and the wiring detection method provided in the embodiment of the present application belong to the same inventive concept, the wiring detection method may also include any other possible steps to control the wiring detection circuit to realize the functions that it can realize and achieve the corresponding technical effects. Similarly, the wiring detection circuit may also include any other possible components to realize the corresponding functions under the control of the wiring detection method, and the embodiment of the present application does not limit this.

[0189] An embodiment of the present application further provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the steps in the above-mentioned method embodiments can be implemented.

[0190] Optionally, the present application also provides a program product, such as a computer-readable storage medium, including a program, which is used to execute any of the above-mentioned wiring detection method embodiments when executed by a processor.

[0191] The above-mentioned integrated unit implemented in the form of a software functional unit can be stored in a computer-readable storage medium. The above-mentioned software functional unit is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) or a processor (English: processor) to perform some steps of the methods of various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (English: Read-Only Memory, abbreviated: ROM), random access memory (English: Random Access Memory, abbreviated: RAM), disk or optical disk and other media that can store program codes.

[0192] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0193] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A wiring detection circuit, characterized in that: Applicable to energy storage inverter; the circuit comprises: a switch unit, a voltage sampling unit, a control processing unit and a first controllable switch; The first end of the switch unit is used to connect the grid-side neutral line, the second end of the switch unit is respectively connected to the load-side neutral line, the first end of the voltage sampling unit and the first sampling end of the control processing unit, and the third end of the switch unit is connected to the first control end of the control processing unit; the switch unit is used to be turned on or off under the control of the control processing unit to control the grid-side neutral line to be connected to the circuit; The second end of the voltage sampling unit is connected to the first end of the first controllable switch; the voltage sampling unit is used to sample the voltage difference between the ground line of the energy storage inverter and the grid-side neutral line and / or the load-side neutral line; The second end of the first controllable switch is respectively connected to the second sampling end of the control processing unit, the ground wire and the housing of the energy storage inverter, and the third end of the first controllable switch is connected to the second control end of the control processing unit; the first controllable switch is used to be turned on under the control of the control processing unit to enable the voltage sampling unit to be powered on and work; The control processing unit is used to sample the initial voltage of the voltage sampling unit when the switch unit is turned off, sample the comparison voltage of the voltage sampling unit when the switch unit is turned on, and determine the connection status of the grid-side neutral line, the load-side neutral line and / or the ground line based on the initial voltage and the comparison voltage.

2. The wiring detection circuit according to claim 1, characterized in that: The voltage sampling unit includes at least one acquisition branch; The first end of each of the acquisition branches is respectively connected to the second end of the switch unit, the load side neutral line and the first sampling end of the control processing unit, and the second end of each of the acquisition branches is respectively connected to the first end of the first controllable switch; Wherein, at the same time, only one of the acquisition branches is connected to the first end of the first controllable switch.

3. The wiring detection circuit according to claim 2, characterized in that: The voltage sampling unit at least includes: a first resistor and a second resistor; The first end of the first resistor is respectively connected to the second end of the switch unit, the load side neutral line and the first sampling end of the control processing unit, the second end of the first resistor is connected to the first end of the second resistor, and the second end of the second resistor is connected to the first end of the first controllable switch.

4. The wiring detection circuit according to claim 3, characterized in that: The voltage sampling unit further includes: a third resistor and a fourth resistor; The first end of the third resistor is connected to the first end of the first resistor, the second end of the third resistor is connected to the first end of the fourth resistor, and the second end of the fourth resistor is used to connect to the first end of the first controllable switch; Wherein, at the same time, only one of the fourth resistor and the second resistor is connected to the first controllable switch.

5. The wiring detection circuit according to claim 3, characterized in that: The voltage sampling unit also includes a second controllable switch; The first end of the second controllable switch is used to connect the second end of the second resistor or the second end of the fourth resistor, the second end of the second controllable switch is connected to the first end of the first controllable switch, and the third end of the second controllable switch is connected to the third control end of the control processing unit; The second controllable switch is used to connect to the second resistor or the fourth resistor under the control of the control processing unit.

6. The wiring detection circuit according to claim 1, characterized in that: The switch unit further comprises at least one third controllable switch; Each of the third controllable switches is sequentially connected in series between the grid-side neutral line and the first end of the voltage sampling unit, and the control end of each of the third controllable switches is respectively connected to the fourth control end of the control processing unit; The third controllable switch is used to be turned on or off under the control of the control processing unit to control the grid-side neutral line to be connected to the circuit.

7. The wiring detection circuit according to claim 1, characterized in that: The control processing unit includes: a collection unit and a micro control unit; The first input end of the acquisition unit is connected to the first end of the voltage sampling unit, the second input end of the acquisition unit is connected to the second end of the first controllable switch, and the output end of the acquisition unit is connected to the input end of the micro control unit; the acquisition unit is used to sample the initial voltage of the voltage sampling unit when the switch unit is turned off, sample the comparative voltage of the voltage sampling unit when the switch unit is turned on, and output the initial voltage and the comparative voltage to the micro control unit; The first control terminal of the micro control unit is connected to the third terminal of the switch unit, and the second control terminal of the micro control unit is connected to the third terminal of the first controllable switch; The micro control unit is used to determine the connection status of the grid-side neutral line, the load-side neutral line and / or the ground line based on the initial voltage and the comparison voltage.

8. A wiring detection method, characterized in that: The wiring detection circuit applied to any one of claims 1 to 7 above, the circuit comprising: a switch unit, a voltage sampling unit, a control processing unit and a first controllable switch; the method comprising: The control processing unit controls the switch unit to turn off, and controls the first controllable switch to turn on; The control processing unit samples the voltage sampling unit in a preset manner to obtain an initial voltage; The control processing unit controls the first controllable unit to be turned off, and controls the switch unit to be turned on; The control processing unit controls the first controllable unit to be turned on, and resamples the voltage sampling unit in a preset manner to obtain a comparison voltage; The control processing unit determines the connection status of the grid-side neutral line, the load-side neutral line and / or the ground line based on the initial voltage and the comparison voltage.

9. The wiring detection method according to claim 8, characterized in that: In the case where the voltage sampling unit includes at least two acquisition branches and a second controllable switch, the control processing unit samples the voltage sampling unit in a preset manner to obtain an initial voltage, including: Sampling and recording the first voltage value of the voltage sampling unit once at a preset time interval until the sampling number reaches a preset threshold and stops sampling; Controlling the second controllable switch to act, and re-sampling and recording the second voltage value of the voltage sampling unit once every preset time interval, until the sampling number reaches a preset threshold and stops sampling; When it is determined that voltage sampling is performed on each of the at least two acquisition branches, the sampling is stopped, and the voltage value corresponding to each of the acquisition branches is used as the initial voltage respectively; The second controllable switch is connected to one of the at least two collecting branches by default.

10. The wiring detection method according to claim 8, characterized in that: The control processing unit determines the connection state of the grid-side neutral line, the load-side neutral line and / or the ground line based on the initial voltage and the comparison voltage, including: calculating a voltage difference between the initial voltage and the comparison voltage; When the voltage difference is greater than or equal to a preset voltage threshold, determining that the connection of the grid-side neutral line, the load-side neutral line and / or the ground line is normal; When the voltage difference is less than a preset voltage threshold, it is determined that the connection of the grid-side neutral line, the load-side neutral line and / or the ground line is abnormal.

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