Self-checking device and system for anti-countercurrent current transformer

Abstract

The utility model provides a self-checking device and system for an anti-countercurrent current transformer, and effectively solves the problems that the accuracy and the safety are reduced when the current transformer is subjected to self-checking through detection software. The self-checking device comprises a driving module, a sampling module, a voltage source, a preprocessing module and a processing module. The sampling module comprises a first sampling resistor and a second sampling resistor; a first sampling resistor in the sampling module is connected with a current transformer in parallel, the first sampling resistor is further connected with a second sampling resistor and a preprocessing module, the preprocessing module is connected with a processing module, the second sampling resistor is further connected with the ground, the first sampling resistor is further connected with a voltage source, and the voltage source is further connected with the current transformer. The convenience of self-checking of the current transformer CT is ensured, and the safety and the accuracy of self-checking of the current transformer CT are ensured at the same time.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a self-test device and system for a current transformer with backflow prevention. Background Art

[0002] In existing energy storage and off-grid systems, current transformers (CTs) are used to control the anti-backflow function. Currently, there is no such hardware detection circuit. Only detection software can detect the current transformers (CTs) when in operation. By controlling the magnitude and direction of the grid-fed energy, it is detected whether the current transformers (CTs) are operating normally. When the detection software is powered on, the primary side of the isolated sampling circuit cannot detect whether the current transformers (CTs) generate induced current and are in a no-voltage state. Only after the system is running can the power of the current transformers (CTs) be detected. If there is a deviation in the power control during this process, it will lead to false detection or misdetection. In addition, this method of detecting the current transformers (CTs) entirely through software has the following defects:

[0003] 1) Testing when the current transformer (CT) is in operation cannot fully guarantee the safety of electrical equipment and personnel;

[0004] 2) Detection when the current transformer (CT) is in operation affects the user experience;

[0005] 3) When the current transformer CT is in operation, it is impossible to distinguish whether the current transformer CT is disconnected or there is a problem with the power control. Utility Model Content

[0006] In view of this, an embodiment of the present application provides a self-test device and system for a current transformer with backflow prevention. This self-test device and system for a current transformer with backflow prevention effectively solves the problem of decreased accuracy and decreased safety when performing self-test on the current transformer through detection software.

[0007] In a first aspect, an embodiment of the present application provides a self-test device for a current transformer with backflow prevention, the self-test device comprising a driving module, a sampling module, a voltage source, a pre-processing module, and a processing module; the sampling module comprising a first sampling resistor and a second sampling resistor;

[0008] The first sampling resistor in the sampling module is connected in parallel with the current transformer. The first sampling resistor is also connected to the second sampling resistor and the preprocessing module respectively. The preprocessing module is connected to the processing module. The second sampling resistor is also connected to the ground. The first sampling resistor is also connected to the voltage source.

[0009] In some embodiments, the sampling module is used to output a standard voltage signal and a sampled voltage signal to the current transformer respectively, and output the standard voltage signal and the sampled voltage signal to the preprocessing module;

[0010] The driving module is used to drive the sampling module to perform sampling under the control of the processing module;

[0011] The preprocessing module is used to preprocess the received sampled voltage signal and the standard voltage signal and output them to the processing module;

[0012] The processing module is used to control the driving module and process the pre-processed sampled voltage signal and the standard voltage signal to obtain a processing result.

[0013] In some embodiments, the self-test device further comprises a connection control module, wherein the connection control module is connected to the processing module and the sampling module respectively;

[0014] The connection control module is used to enable the sampling module to output a voltage signal and a standard voltage signal respectively under the control of the processing module.

[0015] In some embodiments, the connection control module further includes a connection unit and a control unit, the control unit is connected to the processing module; the connection unit is connected to the sampling module;

[0016] The control unit is used to control the connection state of the connection unit under the control of the processing module;

[0017] The connecting unit is used to enable the sampling module to perform sampling under the control of the control unit;

[0018] The sampling module is used to output a sampling voltage signal and a standard voltage signal respectively under the connection of the connecting unit.

[0019] In some embodiments, the processing module includes a processing unit and a confirmation unit; the processing unit is connected to the confirmation unit and the pre-processing module respectively;

[0020] The processing unit is used to process the preprocessed sampled voltage signal and the standard voltage signal output by the preprocessing module to obtain a processing result, wherein the processing result includes a first processing result and a second processing result;

[0021] The confirmation unit is used to output a re-detection signal to the sampling module after the processing unit outputs the second processing result, so that the sampling module re-samples.

[0022] In some embodiments, the confirmation unit is further configured to output a fault signal after the processing unit continuously outputs the second processing result.

[0023] In some embodiments, the processing module further includes a disconnection unit, wherein the disconnection unit is respectively connected to the processing unit, the confirmation unit and the driving module;

[0024] The disconnection unit is configured to disconnect control of the connection control module after the processing unit outputs the first processing result or the confirmation unit outputs a fault signal.

[0025] In some embodiments, the self-test device further comprises a power grid sampling module, wherein the power grid sampling module is connected to the first sampling resistor and the current transformer in parallel;

[0026] The grid sampling module is used to detect the current of energy storage and off-grid connection to obtain the detection result.

[0027] In some embodiments, the self-test device further comprises a power grid start-up unit, wherein the power grid start-up unit is connected to the power grid sampling module;

[0028] The grid starting unit is used to control the grid sampling module to detect the current of energy storage and off-grid after the disconnection unit stops controlling the connection control module.

[0029] In a second aspect, an embodiment of the present application further provides a self-test system for a current transformer with an anti-backflow function, the system comprising a self-test device for a current transformer with an anti-backflow function as described in any one of the preceding claims and a server, wherein the self-test device is communicatively connected to the server;

[0030] The server is configured to send a detection instruction to the self-test device;

[0031] The self-test device is used to receive a test instruction, and respond to the test instruction to start self-testing the current transformer.

[0032] The embodiments of the present application have the following beneficial effects:

[0033] An embodiment of the present application provides a self-test device for a current transformer with backflow prevention. The self-test device includes a drive module, a sampling module, a voltage source, a preprocessing module, and a processing module. The sampling module includes a first sampling resistor and a second sampling resistor. The first sampling resistor in the sampling module is connected in parallel with the current transformer, the first sampling resistor is further connected to the second sampling resistor and the preprocessing module, the preprocessing module is connected to the processing module, the second sampling resistor is further connected to ground, and the first sampling resistor is further connected to the voltage source. The self-test device includes the drive module, the sampling module, the voltage source, the preprocessing module, and the processing module. The self-test device performs self-test on the current transformer through hardware, enabling detection during operation of the current transformer (CT). This avoids limitations of detection software when detecting the current transformer (CT), ensures the convenience of self-testing the current transformer (CT), and simultaneously ensures the safety and accuracy of self-testing the current transformer (CT). BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. 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 relevant drawings can be obtained based on these drawings without creative work.

[0035] Figure 1 Shows a schematic structural diagram of existing detection software;

[0036] Figure 2 A schematic diagram showing the process of existing detection software;

[0037] Figure 3 A schematic structural diagram of a self-test device for a current transformer with backflow prevention provided in an embodiment of the present application is shown;

[0038] Figure 4 A circuit diagram of a connection control module provided in an embodiment of the present application is shown;

[0039] Figure 5 A schematic diagram showing the connection between the power grid sampling module and the power grid starting unit provided in an embodiment of the present application is shown;

[0040] Figure 6 A structural schematic diagram of a self-test system for a current transformer with anti-backflow protection provided in an embodiment of the present application is shown.

[0041] Description of main symbols:

[0042] 1-Self-test device; 2-Server; 11-Drive module; 12-Sampling module; 13-Voltage source;

[0043] 14- preprocessing module; 15- processing module; 16- connection control module; 17- power grid sampling module;

[0044] 18-grid start unit; 121-first sampling resistor; 122-second sampling resistor;

[0045] 151-processing unit; 152-confirmation unit; 153-disconnection unit; 161-control unit;

[0046] 162-Connection unit. DETAILED DESCRIPTION

[0047] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0048] The components of the embodiments of the present application generally described and illustrated in the drawings herein may be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed application, but rather merely represents selected embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative effort are within the scope of protection of the present application.

[0049] Hereinafter, the terms "including", "having" and their cognates, which may be used in various embodiments of the present application, are intended only to indicate specific features, numbers, steps, operations, elements, components or combinations of the foregoing items, and should not be understood as first excluding the existence of one or more other features, numbers, steps, operations, elements, components or combinations of the foregoing items or the possibility of adding one or more features, numbers, steps, operations, elements, components or combinations of the foregoing items.

[0050] Furthermore, the terms “first,” “second,” “third,” etc., are merely used for distinguishing descriptions and are not to be understood as indicating or implying relative importance.

[0051] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by those skilled in the art to which the various embodiments of the present application belong. The terms (such as those defined in generally used dictionaries) will be interpreted as having the same meaning as in the context of the relevant technical field and will not be interpreted as having an idealized meaning or an overly formal meaning unless clearly defined in the various embodiments of the present application.

[0052] The current detection software detects whether the current transformer CT is working properly by controlling the size and direction of the feed network energy, such as Figure 1 As shown, when the detection software is powered on, the primary side of the isolation sampling circuit cannot detect whether the current transformer CT generates induced current and is in a voltage-free state. Only after it is running, through Figure 2 The power of the current transformer CT can be detected only by following the process shown. However, if there is a deviation in the power control during this process, it will lead to false detection or erroneous detection. In addition, this method of detecting the current transformer CT entirely through software has the following defects: detecting when the current transformer CT is in operation cannot fully guarantee the safety of electrical equipment and personnel; detecting when the current transformer CT is in operation affects the user experience; and it is impossible to distinguish whether the current transformer CT is disconnected or there is a problem with the power control when the current transformer CT is in operation.

[0053] Based on this, the self-test device and system for anti-backflow current transformer provided by the embodiment of the utility model effectively solves the problem of reduced accuracy and safety when performing self-test on the current transformer through detection software, and realizes that detection can also be performed during the operation of the current transformer CT, avoiding the limitations of the detection software when detecting the current transformer CT, and ensuring the convenience of detecting the current transformer CT, while also ensuring the safety and accuracy of detecting the current transformer CT.

[0054] In order to understand this embodiment, a self-test device for a current transformer with anti-backflow function disclosed in an embodiment of the present utility model is first introduced in detail.

[0055] Example 1

[0056] Please refer to Figure 3 , is a self-test device 1 for a current transformer with backflow prevention provided in an embodiment of the present application, the self-test device 1 comprising a driving module 11, a sampling module 12, a voltage source 13, a pre-processing module 14 and a processing module 15; the sampling module 12 comprises a first sampling resistor 121 and a second sampling resistor 122;

[0057] The first sampling resistor 121 in the sampling module is connected in parallel with the current transformer CT. The first sampling resistor 121 is also connected to the second sampling resistor 122 and the preprocessing module 14 respectively. The preprocessing module 14 is connected to the processing module 15. The second sampling resistor 122 is also connected to the ground. The first sampling resistor is also connected to the voltage source 13.

[0058] The self-test device 1 includes a driving module 11, which can be composed of a resistor, a transistor, a MOS tube, or a thyristor, etc., which is not limited here. The sampling module 12 includes a first sampling resistor 121 and a second sampling resistor 122. The current sensor CT is connected in parallel to the first sampling resistor 121. The parallel current sensor CT, the first sampling resistor 121, and the second sampling resistor 122 are connected in series. The first sampling resistor 121 is connected to a voltage source 13, that is, the voltage source 13 supplies power to the sampling module composed of the first sampling resistor 121 and the second sampling resistor 122. The second sampling resistor 122 is also connected to the ground, thereby forming a complete loop, so that the sampling module 12 outputs a standard voltage signal and a sampled voltage signal. In order to facilitate the accuracy of the processing module 15 when processing the standard voltage signal and the sampled voltage signal, the preprocessing module 14 needs to preprocess the standard voltage signal and the sampled voltage signal to ensure the accuracy of the processing module. Block 15 processes the standard voltage signal and the sampled voltage signal, wherein the communication between the driving module 11, the sampling module 12, the voltage source 13, the preprocessing module 14 and the processing module 15 can be through wired communication or wireless communication, which can be specifically set according to the actual situation. For example, if the distances between the driving module 11, the sampling module 12, the voltage source 13, the preprocessing module 14 and the processing module 15 are relatively small, a wired communication method can be adopted. If the distances between the driving module 11, the sampling module 12, the voltage source 13, the preprocessing module 14 and the processing module 15 are relatively far, a wireless communication method can be adopted for communication, thereby achieving a better communication effect. The specifications of the voltage source 13 can be selected according to the actual situation, which can be an AC voltage source or a DC voltage source. The driving module 11, the sampling module 12, the voltage source 13, the preprocessing module 14 and the processing module 15 detect the power end of the current transformer CT.

[0059] In combination with the above embodiment, the sampling module 12 is used to output a standard voltage signal and a sampled voltage signal to the current transformer CT respectively, and output the standard voltage signal and the sampled voltage signal to the pre-processing module 14;

[0060] The driving module 11 is used to drive the sampling module 12 to perform sampling under the control of the processing module 15;

[0061] The pre-processing module 14 is used to pre-process the received sampled voltage signal and the standard voltage signal and output them to the processing module 15;

[0062] The processing module 15 is used to control the driving module 11 and process the pre-processed sampled voltage signal and the standard voltage signal to obtain a processing result.

[0063] The sampling module 12 is configured to output a standard voltage signal and a sampled voltage signal, respectively, with the current transformer CT. Specifically, when the current transformer CT is connected in parallel with the first sampling resistor 121 and in series with the second sampling resistor, i.e., the current transformer CT is already connected to the sampling module 12, and due to the impedance inherent in the current transformer CT, the voltage source 13 powers a voltage divider circuit formed by connecting the parallel current transformer CT and the first sampling resistor 121 in parallel with the second sampling resistor 122, so that the sampling module 12 outputs the standard voltage signal through the second sampling resistor 122. Furthermore, if the current transformer CT is not connected to the sampling module 12, i.e., if the current transformer CT is misconnected or missing, the voltage source 13 powers the first sampling resistor 121 and the second sampling resistor 122 in the sampling module 12, thereby outputting the sampled voltage signal through the second sampling resistor 122.

[0064] The driving module 11 is controlled by the processing module 15. After the self-test device 1 is powered on, the processing module 15 controls the driving module 11 to drive the sampling module 12 to perform self-test on the current transformer CT, thereby outputting a standard voltage signal and a sampled voltage signal.

[0065] The preprocessing module 14 is used to preprocess the received sampled voltage signal and the standard voltage signal respectively and then output them to the processing module 15 to avoid the influence of interference or noise in the sampled voltage signal and the standard voltage signal during acquisition. Since the current transformer CT detects the equipment in the energy storage and off-grid, there will be more interference or noise. Therefore, the preprocessing module 14 differentially amplifies the sampled voltage signal and the standard voltage signal, thereby reducing the influence of interference or noise on the standard voltage signal or the sampled voltage signal, and ensuring the accuracy of the processing result obtained by the processing module 15.

[0066] The processing module 15 is used to control the driving module 11 and process the pre-processed sampled voltage signal and the standard voltage signal to obtain a processing result. After receiving the sampled voltage signal and the standard voltage signal, the processing module 15 processes the voltage value of the standard voltage signal and the voltage value of the sampled voltage signal in a manner including comparison. Due to the parallel connection of the current transformer CT and the R after the first sampling resistor 121, 总 If the voltage value of the standard voltage signal is greater than that of the sampled voltage signal, it can be determined whether the current transformer CT is connected or whether there is a missing or wrong connection. The processing module 15 can adopt an ARM series processing chip or other types of processing chips, and the specific settings can be made according to actual conditions.

[0067] In combination with the above embodiment, the self-test device 1 further includes a connection control module 16, such as Figure 4As shown, the connection control module 16 is connected to the processing module 15 and the sampling module 12 respectively;

[0068] The connection control module 16 is used to enable the sampling module 12 to output a voltage signal and a standard voltage signal respectively under the control of the processing module 15 .

[0069] The connection control module 16 receives a control signal sent by the processing module 15. The control signal is generated by the processing module 15 when it needs to perform a self-test on the current transformer CT. The communication method between the connection control module 16 and the processing module 15 is the same as the communication method between the processing module 15 and the driving module 11, the sampling module 12, etc. After receiving the control signal through the communication method between the connection control module 16 and the processing module 15, the sampling module 12 starts sampling the current transformer CT and outputs a standard voltage signal in response to the control signal.

[0070] In combination with the above embodiment, the connection control module 16 further includes a connection unit 162 and a control unit 161, the control unit 161 is connected to the processing module 15; the connection unit 162 is connected to the sampling module 12;

[0071] The control unit 161 is used to control the connection state of the connection unit 162 under the control of the processing module 15;

[0072] The connecting unit 162 is used to enable the sampling module 12 to perform sampling under the control of the control unit 161;

[0073] The sampling module 12 is used to output a sampled voltage signal and a standard voltage signal respectively under the connection of the connection unit 162 .

[0074] The control unit 161 included in the connection control module 16 is used to control the connection state of the connection unit 162 in response to the control signal output by the processing module 15. The connection state of the connection unit 162 includes two states: closed and open. The control unit 161 in the present application can be a relay with a rated current of 1A and a working voltage of 12V. The connection unit 162 is a pin switch of the relay, and the number is 2, namely S1.1 and S1.2, wherein the pin switch S1.1 is set between the voltage source 13 and the first sampling resistor 121, and the pin switch S1.2 is set between the first sampling resistor 121 and the second sampling resistor 122. The connection unit 162 is used to control the control unit 161. In the embodiment of the present invention, the sampling module 12 performs sampling under the control of the control unit 161, that is, the connection unit 162, i.e., the pin switches S1.1 and S1.2, are closed. At this time, the first sampling resistor 121, the second sampling resistor 122, and the voltage source 13 in the sampling module 12 form a complete loop. At this time, the sampling module 12 outputs a sampled voltage signal and a standard voltage signal respectively under the connection of the connection unit 162. If the control unit 161 does not receive the control signal, the connection unit 162, i.e., the pin switches S1.1 and S1.2, are in the open state. Then, the voltage source 13, the first sampling resistor 121, and the second sampling resistor 122 cannot form a complete loop, and thus cannot output the standard voltage signal and the sampled voltage signal.

[0075] In combination with the above embodiment, the processing module 15 includes a processing unit 151 and a confirmation unit 152; the processing unit is connected to the confirmation unit 152 and the pre-processing module 14 respectively;

[0076] The processing unit 151 is used to process the preprocessed sampled voltage signal and the standard voltage signal output by the preprocessing module 14 to obtain a processing result, which includes a first processing result and a second processing result;

[0077] The confirmation unit 152 is configured to output a re-detection signal to the sampling module 12 after the processing unit 151 outputs the second processing result, so that the sampling module 12 performs sampling again.

[0078] The processing unit 151 is configured to process the sampled voltage signal outputted by the preprocessing module 14 after preprocessing with the standard voltage signal to obtain a processing result. The specific processing method is as follows: comparing the sampled voltage signal with the standard voltage signal to determine whether the voltage value of the sampled voltage signal reaches the voltage value of the standard voltage signal to obtain a processing result. The obtained processing result includes a first processing result and a second processing result, wherein the first processing result is yes and the second processing result is no. Only one of the first processing result and the second processing result can exist, that is, when the first processing result exists, the second processing result does not exist, and when the second processing result exists, the first processing result does not exist. When the processing unit 151 outputs the second processing result, it indicates that the voltage value of the sampled voltage signal at this time does not reach the voltage value of the standard voltage signal. At this time, the confirmation unit 152 generates a re-detection signal and outputs the re-detection signal to the sampling module 12 to control the first sampling resistor 121 and the second sampling resistor 122 in the sampling module 12 to re-sample the current transformer CT to confirm whether the current transformer CT is missing, thereby ensuring the accuracy of the self-test of the current transformer CT.

[0079] The sampling module 12, the pre-processing module 14, and the processing module 15 solve the problem of the current transformer CT being unable to be detected due to missed or wrong connection, and achieve the effect of digitally simulating the self-test of the current transformer CT through hardware, thereby realizing the function of comprehensive detection of the current transformer CT and ensuring the safety and reliability of energy storage and off-grid connection.

[0080] In combination with the above embodiment, the confirmation unit 152 is further configured to output a fault signal after the processing unit 151 continuously outputs the second processing result.

[0081] After the processing unit 151 continuously outputs the second processing result of no, that is, after the confirmation unit 152 outputs the re-detection signal and receives the second processing result output by the processing unit 151 again, and the second processing result received again is still no, the confirmation unit 152 determines that the current transformer CT is missing or wrongly connected at this time. At this time, the confirmation unit 152 generates a fault signal and outputs the fault signal. The fault signal can be sent to the monitoring center or the mobile terminal of the relevant personnel, so as to remind the relevant personnel to pay attention and handle it.

[0082] In combination with the above embodiment, the processing module 15 further includes a disconnection unit 153, and the disconnection unit 153 is connected to the processing unit 151, the confirmation unit 152 and the driving module 11 respectively;

[0083] The disconnection unit 153 is configured to disconnect the control of the connection control module 16 after the processing unit 151 outputs the first processing result or the confirmation unit 152 outputs a fault signal.

[0084] The disconnection unit 153 is used to output a first processing result to the processing unit 151, that is, when the processing unit 151 determines that the current transformer CT exists or that the current transformer CT is not missing or wrongly connected, and the self-test work of the current transformer CT has been completed, the control of the connection control module 16 is disconnected, the connection control module 16 stops being powered, and the self-test work of the current transformer CT is stopped. When the confirmation unit 152 outputs a fault signal, the processing unit 151 determines that the current transformer CT does not exist or that the current transformer CT is missing or wrongly connected, and it is determined that the self-test work of the current transformer CT has been completed, the control of the connection control module 16 is disconnected, the connection control module 16 stops being powered, and the self-test work of the current transformer CT is stopped.

[0085] In combination with the above embodiment, the self-test device 1 further includes a power grid sampling module 17, such as Figure 5 As shown, the grid sampling module 17 is connected to the first sampling resistor 121 and the current transformer CT in parallel;

[0086] The grid sampling module 17 is used to detect the current of the energy storage and off-grid current to obtain the detection result.

[0087] The self-test device 1 also includes a power grid sampling module 17, which is connected to a first sampling resistor 121 and a current transformer CT connected in parallel. That is, when the first sampling resistor 121 and the second sampling resistor 122 cannot form a complete loop, the current of the device in the energy storage and off-grid state is detected via the first sampling resistor 121 and the current transformer CT. The power grid sampling module 17 includes an isolation sampling module and a power grid sampling processing module. The isolation sampling module is a mature and conventional technical module in the prior art and will not be described in detail here. The power grid sampling processing module can use a DSP processing chip or other types of processing chips, and can be specifically configured according to actual conditions. The power grid sampling module 17 further enriches the functions of the self-test device 1. The current transformer CT samples the energy storage and off-grid state via the power grid sampling module 17, and the self-test is performed by the sampling module 12, the pre-processing module 14, and the processing module 15. This ensures electrical isolation between the signals collected from the power end and the grid, realizes diversified functions, and further ensures the effectiveness of the self-test device.

[0088] In combination with the above embodiment, the self-test device 1 further includes a power grid start-up unit 18 , and the power grid start-up unit 18 is connected to the power grid sampling module 17 ;

[0089] The grid starting unit 18 is used to control the grid sampling module 17 to detect the current of energy storage and off-grid after the disconnection unit 153 stops controlling the connection control module 16.

[0090] After the disconnection unit 153 stops controlling the connection control module 16, the grid start-up unit 18 controls the grid sampling module 17 to detect the current of the energy storage and off-grid equipment. That is, after the self-test device 1 completes the self-test of the current transformer CT, the grid start-up unit 18 controls the current transformer CT to detect the current of the energy storage and off-grid equipment, thereby confirming whether there is a reverse flow phenomenon in the current of the energy storage and off-grid, thereby ensuring the safety of the energy storage and off-grid.

[0091] Example 2

[0092] The embodiment of the present application also provides a self-test system for a current transformer to prevent reverse flow, such as Figure 6 As shown, the system includes the self-test device 1 for preventing backflow current transformer and the server 2 as described in any one of the items, and the self-test device 1 is communicatively connected to the server 2;

[0093] The server 2 is used to send a detection instruction to the self-test device 1;

[0094] The self-test device 1 is used to receive a test instruction, and respond to the test instruction to start self-testing the current transformer.

[0095] The server 2 sends a detection instruction to the self-test device 1. The detection instruction can be generated by the server 2 when the self-test device 1 is required to perform self-test of the current transformer CT, or can be pre-stored in the server 2 and called when the self-test device 1 is required to perform self-test of the current transformer CT. The self-test device 1 is used to receive the detection instruction, respond to the detection instruction, start self-test of the current transformer CT, and output the obtained processing results, standard voltage signal, sampled voltage signal and related processing data to the server 2, so that the server 2 can monitor the self-test of the self-test device 1 throughout the process.

[0096] The self-test system for the anti-backflow current transformer provided in this embodiment has the same technical features as the self-test device for the anti-backflow current transformer provided in the above embodiment, and therefore can solve the same technical problems and achieve the same technical effects.

[0097] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the above-described embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above-described embodiments within the technical scope disclosed by the present invention, or replace some of the technical features therein with equivalents. Such modifications, changes, or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A self-test device for a current transformer with backflow prevention, characterized in that: The self-test device includes a driving module, a sampling module, a voltage source, a pre-processing module and a processing module; the sampling module includes a first sampling resistor and a second sampling resistor; The first sampling resistor in the sampling module is connected in parallel with the current transformer. The first sampling resistor is also connected to the second sampling resistor and the preprocessing module respectively. The preprocessing module is connected to the processing module. The second sampling resistor is also connected to the ground. The first sampling resistor is also connected to the voltage source.

2. The self-test device according to claim 1, characterized in that: The sampling module is used to output a standard voltage signal and a sampled voltage signal to the current transformer respectively, and output the standard voltage signal and the sampled voltage signal to the preprocessing module; The driving module is used to drive the sampling module to perform sampling under the control of the processing module; The preprocessing module is used to preprocess the received sampled voltage signal and the standard voltage signal and output them to the processing module; The processing module is used to control the driving module and process the pre-processed sampled voltage signal and the standard voltage signal to obtain a processing result.

3. The self-test device according to claim 1, characterized in that: The self-test device further comprises a connection control module, wherein the connection control module is connected to the processing module and the sampling module respectively; The connection control module is used to enable the sampling module to output a voltage signal and a standard voltage signal respectively under the control of the processing module.

4. The self-test device according to claim 3, characterized in that: The connection control module further includes a connection unit and a control unit, wherein the control unit is connected to the processing module; the connection unit is connected to the sampling module; The control unit is used to control the connection state of the connection unit under the control of the processing module; The connecting unit is used to enable the sampling module to perform sampling under the control of the control unit; The sampling module is used to output a sampling voltage signal and a standard voltage signal respectively under the connection of the connecting unit.

5. The self-test device according to claim 1, characterized in that: The processing module includes a processing unit and a confirmation unit; the processing unit is connected to the confirmation unit and the pre-processing module respectively; The processing unit is used to process the preprocessed sampled voltage signal and the standard voltage signal output by the preprocessing module to obtain a processing result, wherein the processing result includes a first processing result and a second processing result; The confirmation unit is used to output a re-detection signal to the sampling module after the processing unit outputs the second processing result, so that the sampling module re-samples.

6. The self-test device according to claim 5, characterized in that: The confirmation unit is further configured to output a fault signal after the processing unit continuously outputs the second processing result.

7. The self-test device according to claim 6, characterized in that: The processing module further includes a disconnection unit, wherein the disconnection unit is respectively connected to the processing unit, the confirmation unit and the driving module; The disconnection unit is configured to disconnect control of the connection control module after the processing unit outputs the first processing result or the confirmation unit outputs a fault signal.

8. The self-test device according to claim 7, characterized in that: The self-test device further comprises a power grid sampling module, wherein the power grid sampling module is connected to the first sampling resistor and the current transformer in parallel; The grid sampling module is used to detect the current of energy storage and off-grid connection to obtain the detection result.

9. The self-test device according to claim 1, characterized in that: The self-test device further comprises a power grid start-up unit, wherein the power grid start-up unit is connected to the power grid sampling module; The grid starting unit is used to control the grid sampling module to detect the current of energy storage and off-grid after the disconnection unit stops controlling the connection control module.

10. A self-test system for a current transformer with backflow prevention, characterized in that: The system comprises a self-test device for the anti-backflow current transformer according to any one of claims 1 to 9 and a server, wherein the self-test device is communicatively connected to the server; The server is configured to send a detection instruction to the self-test device; The self-test device is used to receive a test instruction, and respond to the test instruction to start self-testing the current transformer.

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